SPACE NEWS
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SPACE NEWS
--within the Solar System
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. . See also: "The Drake Equation" on the likelihood of life elsewhere.
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. . Click here for the clearest explanation I've found on dark energy & the expansion of the universe. (eXit to return)
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See Here's our page on just the Space-Elevator concept.
Regardless of when Hubble stops being scientifically useful, it will remain safely in orbit until at least 2013.
The Mars Foundation's hope for humanity's future on Mars is neatly summed up by their slogan: "To arrive, survive and thrive!" Mars Foundation: http://www.marshome.org/
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Dec 29, 06: NASA Ames officials are looking at how the Orion exploration vehicle could be used for a human mission to an NEO, McKay explained. The study is only about halfway complete but initial results look to be positive, he said. McKay said that the main question seems to be finding a NEO that allows for missions that are not too long. Once on station at a planetisimal, crewmembers might release a probe to "crash" onto it. [more like a touchdown...]
. . Progress is being made on defining a human mission to a planetisimal. Experts at several NASA centers are sketching out a prospective piloted stopover at a planetisimal --a trek that could return samples from a targeted space rock as well as honing astronaut proficiency and test needed equipment for other space destinations. "There are many planetisimals that have very low relative velocities with respect to Earth", Lu observed. Identifying an "ideal" NEO is one that's both slow moving and comes close to Earth.
. . A human voyage to a planetisimal would not only trial run Orion equipment --particularly putting high-speed heat shield technology through its paces-- but also could become part of the test program for lunar landings. "There are no handholds on the surface", Lu said. "It may not be a solid surface anyway."
. . Lu said that an Orion spaceship would hover in close proximity to the NEO. "We're talking about an object that's more than likely just 330 feet (100 meters) across, or less. We're talking a big rock or probably a big rubble pile, and likely rotating." From their spot in space, a crew could deploy a remotely-piloted vehicle. Looking out spacecraft windows, an astronaut might fly a robotic probe via a joy stick, Lu envisioned, dropping off packages on the NEO or scooping up select samples for return to Earth.
. . The study is only about halfway complete but initial results look to be positive. In the end, Griffin said, "human expansion into our solar system is fundamentally about the survival of the species, about ensuring better odds for our survival through the promulgation of our species. But one assumption that I know will be justified is that the Moon, the near-Earth planetisimals, and the rest of the solar system contain the resources that will take mankind to the next level of civilization and prosperity. I don't know when it will occur or who will do it, but it will happen. I hope that it will be soon, and that we will be the agents of this great endeavor."
. . "There are a lot of unknowns relative to asteroids", Ailor said, like how they are put together --a key piece of information required in order to deflect any Earth-threatening space rock. "One of the issues that you have is that there's probably some variability.
Dec 26, 06: Russia will cooperate with China on space projects, but will not transfer sensitive technologies that could enable Beijing to become a rival in a future space race, the head of Russia's space agency said.
Dec 22, 06: The environment at the poles of the Moon is relatively benign, making it easier to design a habitat. Temperatures at the poles vary no more than about 50 C all year round, while temps at the equator can vary 250 degrees C from day to night.
. . Astronomers recently utilized Earth-based radio-telescopes to scan the 2 km wide inner edge of the Shackleton crater ridge. The report is that they were not able to identify a distinctive signature of ice deposits pigeon holed within that south pole region.
Dec 20, 06: Mars may currently be too chilly for human colonists, but a U of Arizona student named Rigel Woida is out to change that. Backed by a grant received from NASA, Woida is working on a project for installing large-aperture, lightweight mirrors in orbit above Mars that would heat up a small portion of the planet to help humans colonize the area.
. . The mirrors would sit on 150 segmented, 150-meter-diameter Mylar balloons that would collect sunlight and shine it down over a one-square-kilometer area of Mars's surface. According to Woida, the reflectors would provide daytime illumination and temperatures comparable to those of Tucson, Arizona. One of several benefits to astronauts exploring the planet would be that the heat would save them from having to thaw water needed for fuel on a return trip to Earth.
Dec 15, 06: NASA's planned moon base announced last week could pave the way for deeper space exploration to Mars, but one of the biggest beneficiaries may be the terrestrial energy industry.
. . Nestled among the agency's 200-point mission goals is a proposal to mine Luna for fuel used in fusion reactors --futuristic power plants that have been demoed in proof-of-concept but are likely decades away from commercial deployment. Helium-3 is considered a safe, environmentally friendly fuel candidate for these generators, and while it is scarce on Earth it is plentiful on Luna.
. . While still theoretical, nuclear fusion is touted as a safer, more sustainable way to generate nuclear energy: Fusion plants produce much less radioactive waste, especially if powered by helium-3. But experts say commercial-sized fusion reactors are at least 50 years away.
Dec 15, 06: Scientists studying the tiny grains of material recovered from Comet Wild-2 by Nasa's Stardust mission have found large, complex carbon-rich molecules. They are of the type that could have been important precursor components of the initial reactions that gave rise to the planet's biochemistry. The probe swept up particles fizzing off the object's surface as it passed some 240km from the comet's core.
. . These Wild-2 compounds lack the aromaticity, or carbon ring structures, frequently found in meteorite organics. They are very rich in oxygen and nitrogen, and they probably pre-date the existence of our Solar System.
. . Dr Sandford explained: "That's of interest because we know that in laboratory simulations where we irradiate ice analogues of types we know are out there, these same experiments produce a lot of organic compounds, including amino acids and a class of compounds called amphiphiles which if you put them in water will spontaneously form a membrane so that they make little cellular-like structures."
Dec 14, 06: The Cassini spacecraft orbiting Saturn caused a stir when it spied what appeared to be Yellowstone-like geysers spouting from the south pole of Enceladus. Scientists speculated the eruptions were driven by shallow pools of water lurking just below the icy surface.
. . In an alternative view, other researchers propose that buried ice clathrates —-not liquid water-— are responsible for releasing the towering plumes through a sudden tectonic shift in the crust that causes cracks in the ice and gas to vent.
Dec 14, 06: Detailed observations from the first comet samples returned to Earth are debunking some of science's long-held beliefs on how the icy, celestial bodies form. Scientists expected the minute grains retrieved from a comet Wild 2 to be made up mostly of interstellar dust —-tiny particles that flow through the solar system thought to be from ancient stars that exploded and died.
. . Instead, they found an unusual mix of primordial material as if the solar system had turned itself inside out. Hot particles from the inner solar system migrated out to the cold, outer fringes beyond Pluto where they intermingled and congealed to form a comet. "People imagine that comets form in total isolation, which is definitely not true", said Don Brownlee, a University of Washington astronomer who is the principal scientist. Brownlee estimated that up to 10% of materials in comets may come from the inner solar system.
Dec 14, 06: Astronomers have peered beneath the smooth surface of baby-face regions of Mars. Craggy lines and craters wrinkle the subsurface, revealing an impact-riddled past whose history has since been covered over in the low plains of Mars' northern hemisphere.
. . The abundance of buried craters that the radar has detected beneath Mars' smooth northern plains means the underlying crust of the northern hemisphere is extremely old, "perhaps as ancient as the heavily cratered highland crust in the southern hemisphere." Mars shows a striking difference between its northern and southern hemispheres. Almost the entire southern hemisphere has rough, heavily cratered highlands, while most of the northern hemisphere is smoother and lower in elevation.
Dec 13, 06: Scientists are deadlocked over the severity of the next sunspot cycle, which could produce powerful solar storms that can disrupt communication systems on Earth.
Dec 13, 06: The international Cassini spacecraft spotted a nearly 1.5km-high mountain range shrouded in hazy clouds on Saturn's giant moon Titan, scientists reported.
. . The mountains, which stretch for nearly 150 km, surprised researchers who re-analyzed the images to double-check that they were real and not shadows of other surface features. The mountains are the tallest ever seen on Titan and probably formed from the same process that occurs in the Earth's mid-ocean ridge. Scientists speculated that hot material beneath Titan's surface gushed up when tectonic plates pulled apart, creating the mountain range. Cassini found the summit of the range capped with brilliant white layers that are likely deposits of methane or another organic material.
Dec 11, 06: A study found man's burning of fossil fuels and increase of CO2 emissions will make the Earth's outer atmosphere above 100km 3% less dense by 2017. They found a decrease of about 5% between 1970 and 2000.
. . Although scientists say that CO2 contributes to global warming closer to Earth's surface, in the thinner outer atmosphere where space craft orbit, a cooling effect takes place. Solar activity also impacts the outer atmosphere.
. . A steady stream of space launches since Sputnik has left about 10,000 objects bigger than the size of a grapefruit, and 100,000 larger than a centimeter. The International Space Station now in orbit must readjust its path several times a year to avoid colliding with such debris; a chance hit with a spacewalking astronaut could prove fatal.
. . A Russian cosmonaut increased by one the number of man-made objects in space by hitting a golf ball into the final frontier during a space walk last month.
Dec 8, 06: A major flare on the Sun earlier this week generated what scientists are calling a solar tsunami. The tsunami-like shock wave, formally called a Moreton wave, rolled across the hot surface, destroying two visible filaments of cool gas on opposite sides of the visible face of the Sun. Astronomers using a prototype of a new solar telescope in New Mexico recorded the action.
Dec 6, 06: Images taken by NASA's Mars Global Surveyor spacecraft suggest the presence of liquid water on the Martian surface, a tantalizing find for scientists wondering if the Red Planet ever has harbored life. The orbiting U.S. spacecraft allowed scientists to detect changes in the walls of two Martian craters that may have been caused by the recent flow of water, a team of researchers said. Scientists previously had established that two forms of water --ice at the poles and water vapor-- exist on Mars, but liquid water is crucial to nurture life.
. . The scientists compared images of the Martian surface taken seven years apart and found the existence of 20 newly formed craters caused by impact from space debris as well as the evidence suggesting liquid water trickling down crater walls. The paper said water seemed to have flowed down two gullies in the past few years, even though liquid water cannot remain long on the planet's frigid, nearly airless surface because it would rapidly freeze or evaporate. This seemed to support the notion that liquid water may exist close enough to the planet's surface in some places that it can seep out from time to time.
. . The scientists proposed that water could remain in liquid form long enough on the surface to transport debris downslope before freezing. The two bright new deposits are each several hundred meters or yards long.
. . They cited a possible alternative explanation that these features were caused by movement of dry dust down a slope.
Dec 4, 06: NASA has decided to pursue a base on Luna. The space agency rolled out today a strategy and rationale for robotic and human exploration of Luna --determining that a lunar outpost is the best approach to achieve a sustained human presence there.
. . The base would be built in incremental steps, starting with four-person crews making several seven-day visits. The first mission would begin by 2020, with the base growing over time, beefed up with more power, mobility rovers and living quarters. The Lunar base would eventually support 180-day stays, a stretch of time seen as the best avenue to establish a permanent presence there, as well as prepare for future human exploration of Mars.
. . "What we're looking at are polar locations... both the north pole and south pole", said NASA Deputy Administrator Shana Dale. Picking between the two poles will be done once NASA's Lunar Reconnaissance Orbiter begins surveying Luna after its launch in October 2008.
. . One particular area that's already receiving high marks by NASA's lunar architecture team is at the South Pole --a spot on the rim of Shackleton Crater that's almost permanently sunlit. "It's also adjacent to a permanently dark region in which there are potentially volatiles that we can extract and use."
. . A key technology yet to be defined is a lunar lander--hardware that can be used in piloted or unpiloted mode to develop a capability on Luna more rapidly. The lander will be designed to touchdown anywhere on Luna... likened to a lunar pickup truck.
. . "The door is wide open in terms of participation by internationals", Dale noted, and that includes providing power, habitats, mobility on the lunar surface, as well as technology to use the resources on Luna to life off the land. Dale said that 2007 will feature "extensive dialogue with other countries" about the ways in which they want to participate in exploration activities.
. . The plan would take 16 years, twice as long as NASA's first trip to Luna took in planning. NASA has refused to estimate a price tag for the project.
. . The new UK science minister has met the Nasa chief to discuss possible involvement in lunar missions.
Dec 1, 06: Potentially dangerous small space rocks are smashing into the Moon a lot more often than was expected, according to an ongoing NASA study. "We've now seen 11 and possibly 12 lunar impacts since we started monitoring the Moon one year ago", said Bill Cooke, head of NASA's Meteoroid Environment Office. "That's about four times more hits than our computer models predicted.
. . If further study proves the pace to be accurate, it could figure into plans for putting people there. A collision with a spacesuit or a habitation module, even from a small object, could be fatal.
. . Most meteoroids that enter Earth's atmosphere burn up harmlessly. The bulk of shooting stars are caused by stuff no bigger than sand grains and a few pea-sized objects. But even something as big as a basketball will usually burn up, in a spectacular fireball, before hitting Earth's surface. The Moon, with no atmosphere, sees it all rain down.
. . They documented two impacts during last month's Leonid meteor shower. "The flashes we saw were caused by Leonid meteoroids 5 to 8 cm in diameter", Cooke said today in a NASA statement. They hit with energies equal to 150 to 300 pounds of TNT.
. . Leonid meteors, leftover chunks from a comet, are particularly dangerous because they move against the path of our own orbit around the Sun, so we hit them head-on at greater speed than much other debris. This results in a greater release of energy at impact.
Nov 30, 06: Now heading outward on its lengthy trek to tiny Pluto, NASA's New Horizons spacecraft is on course to zip by gigantic Jupiter early next year. It's caught the first glimpse of its distant destination: the dwarf-planet Pluto.
. . The New Horizons probe, set to swing by Pluto and its 3 moons in 2015, plucked the small planet from a star-filled image during a checkout period using the spacecraft's long range camera. It's snapped photos of the planetisimal JF56 --during a June 13 pass-- as well as the star Messier 7 and the gas giant Jupiter. They're hoping to send their spacecraft past Pluto to visit at least one other icy object in the distant Kuiper Belt.
. . New Horizons is currently speeding through the solar system at about 20.8 kilometers per second with respect to the Sun. That's about 74,880 kph.
Nov 29, 06: China's unfolding space plans include that country's first foray into exploration of the Moon. A Chang'e I lunar orbiter is nearing final construction, being readied for rocketing to the Moon in 2007.
Nov 29, 06: If NASA's 2009 Mars Science Laboratory (MSL) reaches the red planet's surface in one piece, the agency will owe a debt of gratitude to the Sikorsky S-64 Skycrane heavy-lift helicopter.
. . Like its namesake, NASA's Sky Crane carrier platform will hover above its drop site--albeit with retrorockets rather than rotor blades--and lower its payload, the compact car-sized MSL rover, to the surface using a winch and tether. As soon as the rover is ready to roll, the tether connection will be severed and the Sky Crane will fly off and crash land a short distance away.
. . NASA settled on the Sky Crane approach in 2003 after concluding that the 775-kilogram nuclear-powered MSL was too massive for the airbag landing that worked so well for the 1996 Mars Pathfinder and the 2003 Mars Exploration Rovers. Another possibility was a three- or four-legged lander assisted by parachutes and retrorockets, he said. But after the failure of the Mars Polar Lander, which employed that mode, NASA was open to trying something a little different
. . Thrusters on the Sky Crane landing system ignite at 1,000 meters above the surface, providing a controlled descent. At 35 meters, the Sky Crane will begin lowering the rover on a tether --similar to the way the Sikorsky S-64 delivers underslung payloads-- as it continues its descent. When the rover's wheels touchdown, the tether is severed and the Sky Crane platform flies off to land 500 meters to 1000 meters away, Steltzner said.
. . While some scientists would like NASA to put instruments on the Sky Crane, essentially transforming it into a stationary lander, Steltzner said that is not currently in the plans.
Nov 29, 06: Japanese scientists have expressed their delight at the performance of the Hinode spacecraft which was sent into orbit in September to study the Sun. The probe has returned remarkable close-up images of solar features that researchers hope will yield valuable new insights into the star's activity. Hinode's primary goal is to investigate solar flares, colossal explosions that occur in the Sun's atmosphere. The new pictures, which have been colored and turned into movies, show the behavior of sunspots.
Nov 28, 06: Astrophysicists are discussing Lunar plans, including the idea of setting up telescopes on the surface. Now that scientists have developed a blueprint for how the next generation of astronauts will whisk back to the Moon, it's time to figure out what to do when they get there.
. . One idea is to set up a liquid-mirror telescope there. They spin to create a parabola at the surface. The handful of these telescopes on Earth are limited in size because the spinning creates wind that disrupts the mirror-like surface. By placing infrastructure there, future missions could rely on the already established equipment, meaning less payload to lug up there.
. . There are also hurdles to ponder. A layer of fine, particles, the consistency of talcum powder, covers the lunar bedrock and reaches several feet thick. It can generate dense dust clouds. Unlike the household variety, lunar dust is glass-like with a core of iron, giving it magnetic properties. Figuring out ways to ensure dust-free instruments is a major priority. Another issue is levitated dust, which occurs when the Sun's energy cause dust grains to become electrically charged. [So it might settle on the surface of the mirror!]
Nov 27, 06: Arizona's famous Meteor Crater is a long way from the Moon. But for a menagerie of intelligent robots hoping to earn supporting roles in NASA's lunar exploration plans, the massive impact crater west of Flagstaff is center stage.
. . In September, several such robots and an autonomous Moon buggy called Scout were put through their paces in the rough desert terrain. In addition to Scout, NASA's current line up of field assistants includes a nimble six-legged rover called Athlete, a dexterous humanoid torso on wheels called Centaur, and K-10, a boxy little rover specially equipped for site survey work.
. . Culbert said all four robots help NASA in one way or another to address the three big themes of the Human Robotics Systems program: surface mobility, surface handling, and human-systems interaction. "The interaction between robots and humans is very important to me", Culbert said. "Industrial robots are typically behind barriers and big alarms ring if humans come within 10 feet. Our robots live with the humans."
. . The funding reduction ruled out building a high-fidelity prototype out of mission-grade components as the team originally proposed. But the team has managed to build three somewhat lower fidelity Athlete prototypes, including two fully-functional vehicles, from commercially-available components. The semi-autonomous rovers run software brought over from the Mars Exploration Rover program.
. . If additional money is forthcoming, Culbert said the program would like to build a new moon buggy next year equipped with an active suspension system tuned to handle tougher terrain. Human Robotic Systems group may also build a crane in 2007 and possibly add it to one of the Athlete rovers.
Nov 17, 06: A U of Arizona (UA) project doesn't want to 'terraform' the whole Red Planet. In fact, this project is funded with a very modest $9,000 grant from NASA and just wants to heat a one-square kilometer area of Mars' surface by using space mirrors as reports New Scientist. The plan is to establish a 1.5-kilometer diameter array made up of 150 segmented, 150-meter-diameter mylar balloons that would collect sunlight and shine it down over a future Mars base camp where the temperature would be 20°C.
. . The concept calls for 300 reflective balloons, each 150 meters across, arranged side-by-side to create a 1.5-kilometer-wide mirror in orbit around Mars. The mirror would focus sunlight onto a 1-kilometer-wide patch of Mars's surface. This would raise the temperature in this patch to a balmy 20° Celsius (68° Fahrenheit) from Mars's typical surface temperature of between -140° C and -60° C (-220° and -76° F).
. . The extra warmth would mean the astronauts would not need heavily insulated suits or living quarters, allowing them to work more easily. The extra sunlight would also boost power from solar cells.
Nov 16, 06: NASA is appraising a human mission to a near-Earth planetisimal --gauging the scientific merit of the endeavor while testing out spacecraft gear, as well as mastering techniques that could prove useful if a space rock ever took aim for our planet.
. . Major pieces of the Constellation Program --such as the Orion crew vehicle-- are meant to support transport of humans and cargo to the Moon and to the Space Station, while future efforts would sustain missions to Mars and beyond. Astronauts, engineers and scientists at NASA's Johnson Space Center have been looking into the capabilities of the Orion vehicle for a mission to a near-Earth planetisimal.
. . Former Apollo astronaut, Russell Schweickart, Chairman of the B612 Foundation, a group with the goal of significantly altering the orbit of an planetisimal, in a controlled manner, by 2015. Schweickart said that there are a number of "forward looking reasons" to put planetisimals on NASA's lofty Moon, Mars and beyond agenda.
. . The value of planetisimals for on-the-spot resources, for one, was noted by Schweickart. Secondly, validating command and control skills in piloting up to an planetisimal would be beneficial, he said. Furthermore, a human venture to a space rock may well accelerate precursor robotic surveys of planetisimals, Schweickart observed. "Early unmanned visits to planetisimals...it's the same pattern as we did with the Moon and we're doing right now with Mars. "That kind of early demonstration mission might last no more than 60 or 90 days", Durda said, "and take the crew no farther than a few lunar distances away from Earth."
. . Durda said he could imagine that such a flight might be made before the first lunar landing even --perhaps after a lunar orbital mission or two-- in order to try out spacecraft systems on an even longer-duration flight. "Astronauts could collect a rich array of samples from the most scientifically interesting sites on the near-Earth object--dating back to the earliest days of the solar system--set up a pilot resource extraction experiment, demonstrate technology necessary for a future near-Earth object deflection mission, and look back at Earth from millions of miles away. The view would be breathtaking", he said.
. . A human journey to an planetisimal stretches our deep-space legs, Jones said, "and challenges ourselves operationally even after we return to the Moon.
Nov 14, 06: The lunar surface is a harsh landscape; a bone dry expanse of impact-pummelled rock whose "seas" have long been known as a misnomer. The only precipitation is in the form of solar and cosmic radiation that gradually darkens the dust and corrupts the cells of any astronauts present.
. . Yet amidst this hostile landscape, a number of safer havens exist where the lunar surface escapes much of this sleet of radiation. One such benign feature, named Reiner Gamma, lies on Luna's Earth-facing side and is marked by a 60 km-long bright swirl and one of the strongest magnetic fields found on the lunar surface.
. . "The Moon presently has no global magnetic field similar to the Earth's. The observed fields [such as that at Reiner Gamma] are caused by permanent magnetization of parts of the lunar crust", said Lon Hood of the University of Arizona. "Current evidence suggests that impact-basin ejecta materials [material blasted out by huge planetisimal or comet impacts] are the most likely sources of many or all of the magnetic fields", Hood said. "These ejecta contain microscopic metallic iron particles that are the carriers of the magnetization."
. . The bright swirls of Reiner Gamma are a by-product of the contorted magnetic field arching overhead, and there are currently two models for the formation of the enigmatic swirls associated with the fields.
. . The first hypothesis is that the swirls consist of secondary crater ejecta whose bright deposits have been preserved by a strong local crustal magnetic field. One likely candidate for the bright ejecta preserved at Reiner Gamma is that of the nearby three-billion-year-old crater Cavalerius. The magnetic field present over Reiner Gamma would deflect the solar wind and preserve the ejecta as a bright footprint of the magnetic field above.
. . The second mechanism for the swirls' formation is the relatively recent impact of a comet nucleus. Such an event would create a feature similar to Reiner Gamma and also magnetize the lunar surface.
. . Not only does the magnetic field preserve an unsullied lunar surface but it would partially protect any astronauts strolling beneath, 'The lunar fields are strong enough to deflect solar wind ions with energies of several kilo-electron-volts,' Hood said.
. . Reiner Gamma's magnetic shield also channels the solar ions it does divert into narrow regions surrounding the feature, another boon for human exploration. "This would concentrate solar wind hydrogen and helium-3 locally which might be beneficial to increase the efficiency of mining these for resource applications", Hood said. Helium-3 is a light isotope of helium carried in the solar wind and is a potential fuel for efficient and non-polluting nuclear fusion. The hydrogen would also be essential to the manufacture of water for a lunar outpost.
Nov 11, 06: The European Space Agency (Esa) has pushed back the launch of its rover mission to Mars from 2011 to 2013.
. . The decision will not significantly delay the mission's arrival at Mars. But it does reflect a growing will to push for an upgrade to the ExoMars project which could raise its cost from roughly 500m euros to 800m euros. It would involve launching the rover on an Ariane 5 rocket instead of a Russian Soyuz, releasing enough mass to send an orbiting spacecraft along for the ride. The orbiter would communicate with the lander and relay data with Earth.
. . The move to 2013 will allow more time for negotiating a new budget. In addition, some technology envisaged for the mission is unlikely to be ready by 2011.
. . The current mission scenario envisages ExoMars using a US spacecraft called Mars Reconnaissance Orbiter (MRO) for data relay. However, officials have no guarantee that MRO will still be operational by the time ExoMars arrives.
. . Another way is to use novel "vented airbags" to cushion the rover's landing. These inflate like pillows under the rover and can support heavier payloads than "classical" or "bouncing ball" airbags.
. . With a launch in 2011, ExoMars would have spent two years in a heliocentric orbit waiting for Martian dust storms to settle down so that it could land. Dr Coradini said that by missing out these two years in space, the spacecraft would be spared extensive bombardment by charged particles originating in the Sun and outside the Solar System which could damage delicate scientific instruments.
Nov 10, 06: The Indian Space Research Agency (ISRO) has proposed starting a human spaceflight program, with the first manned flight taking place by 2014 leading up to landing an Indian national on the Moon by 2020, ahead of China.
Nov 8, 06: It's believed that Luna hasn't experienced any volcanic activity for at least three million years, but a new look at some old evidence suggests otherwise. Examining photographs and data from the Apollo missions, scientists noticed that volcanic gas has been released from the lunar surface within the last 1 million to 10 million years.
. . The researchers focused on a D-shaped area first noticed by the Apollo astronauts, called the Ina Structure. Its surface expressions were very fresh with sharp edges, hinting to the fact that they were only recently exposed. "Something that razor sharp shouldn't stay around long", Schulz said. "It ought to be destroyed within 50 million years."
Nov 8, 06: A freaky storm two-thirds the diameter of Earth and unlike anything ever seen has been spotted on Saturn. The tempest, some 8,000 kilometers wide (5,000 miles), has an oddly human-looking hurricane-like eye. But it is very different from a terrestrial hurricane, scientists said today.
. . NASA's Cassini spacecraft photographed the huge storm. It swirls with 350 mph winds at the ringed planet's south pole. It has a remarkably well-defined eye ringed by clouds that soar 30 to 75 km high, or up to five times taller than hurricane clouds on Earth. "It looks like a hurricane, but it doesn't behave like a hurricane." The storm's eye, eye-wall and spiral arms are all "hurricane-like", they say.
. . Yet this storm rotates around Saturn's south pole --astronomers say the pole seems to be within the storm's eye and the system seems locked in place. It has a well-developed eye ringed by towering clouds that soar 20-45 miles above those in the dark center, two to five times higher than clouds in our thunderstorms and hurricanes. Its winds howl clockwise at 550 kph (350 mph). Other gas-planet storms, like the Red Spot on Jupiter and many smaller storms on both Saturn and Jupiter, do not have eyes.
. . This newfound storm's eye offers a window into Saturn. "The clear skies over the eye appear to extend down to a level about twice as deep as the usual cloud level observed on Saturn, and reveals a mysterious set of dark clouds at the bottom of the eye."
. . The images --essentially a 14-frame movie-- were captured over a period of three hours on October 11 by the U.S. space agency's Cassini spacecraft as it passed about 210,000 miles from the planet.
India's state-run space agency approved its first indigenous manned mission into space on Tuesday, aiming to put an astronaut outside the earth's atmosphere by 2014.
Nov 7, 06: China's next Shenzhou spacecraft to launch astronauts into orbit is under construction as officials draw up plans for the 2008 space shot, the country’s state-run media reported.
. . The country's next crewed spaceflight, Shenzhou 7, is slated to launch three astronauts spaceward and include at least one spacewalk as China moves forward with plans to build an orbital space station.
. . They'll don $20 million spacesuits, which weigh about 100 kg on Earth.
. . One major difference is the Shenzhou’s ability to leave its solar array-equipped orbital module in space for months at a time. Such modules could serve as a docking target for future spacecraft, or as the foundation of a small space station.
Nov 7, 06: Ultra-tiny dust grains can gum up the works of vital hardware on Luna. There's also a possible risk to health from breating the dust. Moonwalkers were covered from helmet to boot with lunar dust. Also tagged as the "dirty dozen", astronauts on the various Apollo missions worked long hours in the lunar environment, setting up science equipment and collectively bagged 382 kg of rock and other surface material for shipment back to Earth.
. . As NASA planners gear up to replant astronauts on the lunar surface before 2020, scientists and engineers are grappling with how best to certify a safe and productive stay for 21st-century moonwalkers. From gauge dials, helmet sun shades to spacesuits and tools, the "stick-to-itness" of dust during the Apollo missions proved to be a noteworthy problem, Halekas reported. Most amusingly, he added, even the vacuum cleaner that was designed to clean off the dust clogged up and jammed.
. . Although the lunar environment is often considered to be essentially static, Halekas and his fellow researchers reported at the workshop that, in fact, it is very electrically active. The surface of the Moon charges in response to currents incident on its surface, and is exposed to a variety of different charging environments during its orbit around the Earth. Those charging currents span several orders of magnitude.
. . Dust adhesion is likely increased by the angular barbed shapes of lunar dust, found to quickly and effectively coat all surfaces it comes into contact with. Additionally, that clinging is possibly due to electrostatic charging.
. . The most critical effect of lunar dust, however, may be on astronaut health. With each Apollo mission to the Moon, astronauts remarked about the "gun powder" smell when they took off their helmets inside their lunar lander after climbing back in from a moonwalk. Several astronauts reported respiratory or eye irritation.
. . There's the possibility that ultra-small particles of the lunar dust are capable of moving from human lungs directly into the blood stream. Moreover, these fine particles consist almost entirely of glass containing myriads of nanophase metallic iron --a constituent that might interact with a person's hemoglobin and spur oxygen-deprivation effects.
. . The Lunar Soil Magnetic Collection device-the LSMAC for short, would not only pull the iron-tainted soil down a tube but also effectively capture the dust as well. The operation of this "coil vacuum" equipment on the Moon is foreseen as a kind of electronic conveyor belt.
. . Conceptually, Eimer and Taylor reported that a lunar surface-mining operation could use the LSMAC to gather and transport soil-plus dust-across stretches of moonscape to processing plants. This method of handling and collecting lunar surface materials would help keep in check the stirring up of dust in the process.
Oct 31, 06: The surviving portion of the Deep Impact space probe that watched as its other half smashed into a comet on July 4 is being sent on a mission to study another comet. NASA announced that it has accepted a proposal by the University of Maryland, which developed and manages Deep Impact, to send the vehicle on an extended mission to intercept Comet Boethin. Deep Impact will pass by it in December 2008, & its instruments can examine the comet.
Oct 28, 06: An ocean of water once wrapped around Mars, suggests the discovery of soil chemicals by NASA’s rovers. But the same chemicals also indicate that life was not widespread on the planet at the time the ocean was present.
. . Sulphates, which form most readily in liquid water, had already been detected by the Spirit and Opportunity rovers. The minerals have been interpreted as evidence for past bodies of water on the surface. But it has not been clear how large these bodies of water might have been. Now, a new analysis of rover data suggests that the sulphates were once dissolved in a planet-wide ocean.
. . The researchers point out that phosphates, which are also linked to water, are also present at both sites. More importantly, the ratio of phosphates to sulphates is about the same at both locations. They say the most likely explanation for this is that any local variations were smoothed out by mixing in a planet-wide ocean.
. . The phosphorus was probably leached from rocks in the form of calcium phosphate, the researchers say. The fact that it appears to have been dissolved and mixed with sulphates in large amounts suggests that the hypothesised ocean must have been very acidic, because calcium phosphate only dissolves well in acidic water.
. . A phosphorus-rich ocean is a bad sign for past Mars life. Phosphorus is an important element for life on Earth, and is quickly extracted from the environment by organisms. If life were extensive on Mars, it would not have left so much phosphorus dissolved in the water, the researchers say.
Oct 24, 06: NASA’s twin Viking spacecraft may have missed signs of life during their examination of the Martian surface 30 years ago. Researchers now say that the landers’ experiments were not sensitive enough to find life and in any case may not have been able to spot the strange forms that Martian life might take.
. . It's now claimed that the GCMS instrument was incapable of detecting organic compounds even in Mars-like soils from various locations on Earth. This includes Chile's Atacama desert, where other tests prove that living microbes are indeed present. In some soils –-including samples taken from Rio Tinto in Spain, which contain iron compounds similar to those detected in Mars soils by NASA's rover Opportunity-- the sensitivity of the GCMS was actually a million times lower than its claimed threshold for detection.
Oct 23, 06: NASA's goal of returning astronauts to Luna by 2020 and pushing on to Mars will require significant strides in both understanding and warding off of hazardous space radiation, according to a report. NASA has long known that astronauts on long-duration flights to the Moon or Mars will be subjected to higher levels of radiation from solar flares and cosmic rays than those aboard the
. . International Space Station (ISS), flies within the Earth's protective magnetic field. But those far-flung missions may prove intractable unless the space agency makes major leaps on both the biological and solar physics fronts.
. . NASA's current guidelines set career caps on the radiation exposure for astronauts with the limits designed to lead to a less than 3% increase in the risk of death from cancer, according to the report. Those radiation limits vary with age and gender. For 30-year-old astronauts, the maximum allowable mission length for a female is set at 54 days and reaches 91 days for male spaceflyers, the report stated. By age 55, the total days in space max out at 159 days for female astronauts and 268 days for their male counterparts. All of those limits are less than three consecutive six-month ISS missions, as well as an extended 1,000-day Mars mission.
. . A potential tool kit, suggested in the report, blends several methods of radiation detection and risk mitigation including: active and passive shielding for lunar or Martian bases, solar storm shelters and alert systems, dosimeters, forecast models and a series of other potential countermeasures.
. . Last month, the space agency announced the selection of 12 new radiation biology research proposals specifically aimed at understanding and reducing risks for Moon- or Mars-bound astronauts.
Oct 23, 06: Earth's recent warming trend might in part be due to a lack of star"light" reaching our planet, a new study suggests. But other scientists are not so sure.
. . According to a theory proposed a decade ago, when a star explodes far away in the Milky Way, cosmic rays --high-speed atomic particles-- go through the Earth's atmosphere and produce ions and free electrons. The released electrons act as catalysts and accelerate the formation of small clusters of sulfuric acid and water molecules, the building blocks of clouds. Therefore, cosmic rays would increase cloud cover on Earth, reflecting sunlight and keeping the planet relatively cool.
. . However, because the Sun's magnetic field --which shields the Earth from these rays-- doubled in intensity during the last century, there has been a reduction in cloudiness, a possible contributor to Earth's warming.
. . Scientists at the Danish National Space Center mimicked chemistry of the lower atmosphere in a large reaction chamber. They created a mixture that contained gasses at realistic concentrations and used an ultraviolet lamp to act as the Sun. Microscopic droplets, precursor to clouds, started floating in the air of the reaction chamber.
. . The results however, may not transfer to natural conditions outside the controlled laboratory environment. "Studies that have evaluated the claims that global cloud cover is related to changes in cosmic rays find that if you re-examine this matter outside of the brief period which they used, the relationship falls apart", said Raymond Bradley director of the Climate System Research Center at the University of Massachusetts.
Oct 20, 06: Right now, the materials to support an elevator capable of traveling all the way to geosynchronous orbit are not available. However, it is believed that super-strong materials like carbon nanotubes, could open up a whole new means of space travel, one that could eliminate the need for expensive rockets with dangerous propellants. The technology, therefore, is worth researching.
. . Today, of course, the goal is less lofty: 13 teams are vying for the opportunity to prove that their respective "space elevators" can climb up a 200-foot ribbon. The teams, staffed mostly by engineering students, have come up with a wide array of creative ideas.
Oct 18, 06: New high-resolution radar images of Luna have diminished hopes that the lunar poles might harbor water that could sustain future lunar and solar system explorations.
Oct 17, 06: A near-Earth planetisimal is made of two motley parts that dance around each other like a miniature Earth and Luna, a new study finds. In May 2001, the planetisimal 1999 KW4 passed within about 4.8 million km of Earth. Scientists bounced radar off the planetisimal's surface and, by measuring the strength and lag time of the returning signals, were able to calculate many of its physical properties.
. . The radar imaging shows that Alpha, KW4's larger component, is about 1.5 km wide and essentially a floating pile of rubble held together by gravity; about 50% of it is empty space. The smaller piece, Beta, is about a quarter of Alpha's size and elongated, like a peanut. Beta orbits Alpha every 17 hours from a distance of about 2.5 km.
. . Alpha is spinning at close to its break-up speed. It makes one complete revolution in about three hours; if it spun any faster, material from its equator would fly off into space. Scientists think that KW4's two pieces once belonged to a larger planetisimal that broke apart during a perilously close pass by the Earth.
. . Another possibility is that sunlight shining on the precursor planetisimal caused it to spin so fast it broke in two. Because of their odd shapes, planetisimals can sometimes act like solar sails, catching sunlight the way sailboats catch wind.
. . The latest observations show that there is no chance that KW4 will hit Earth within the next 1,000 years.
Oct 17, 06: Scientists were excited when they pulled a 154-pound meteorite from deep below a Kansas wheat field, but what got them most electrified was the way they unearthed it. The team uncovered the find a meter under a meteorite-strewn field using new ground-penetrating radar technology that someday might be used on Mars. It was that technology which pinpointed the site and proved for the first time that it could be used to find objects buried deep in the ground and to make an accurate three-dimensional image of them.
. . Fewer than 1% of the meteorites discovered on earth are pallasite meteorites, known for their crystals embedded in iron.
. . More than 15,000 pounds of meteorites have been recovered from the area.
Oct 17, 06: A NASA spacecraft orbiting Mars is using the most powerful cameras ever pointed at the Red Planet to study its climate cycles and whether there is enough water to support a manned mission.
. . Images taken during a test of the Mars Reconnaissance Orbiter's instruments showed clay-rich areas that could have supported life and frost, and layered deposits of ice and dirt at the polar ice cap indicate "dynamic climate changes" as recently as 100,000 years ago.
. . The orbiter dropped into a low orbit around Mars last month to map the planet's subsurface minerals, monitor its atmosphere and look for evidence of enough subsurface ice or water to process into oxygen, concrete and rocket fuel for manned exploration.
. . The orbiter will also use HiRISE, its super high-resolution camera, to find landing sites for the Phoenix Mars Lander, set to arrive in 2008, and for the 2009 arrival of the Mars Science Laboratory, a larger version of the twin robotic geologists Spirit and Opportunity.
Oct 12, 06: Scientists at the Division of Planetary Sciences meeting in Pasadena, California, this week said that data streaming from the Venus Express probe had provided unprecedented detail of the Venusian atmosphere and the first-ever peek at its lower strata.
. . They hope the spacecraft will help answer fundamental questions about the planet's atmospheric composition and dynamics, as well as solve key Venus puzzles: what drives its "super-rotation"; are its volcanoes active; and just what is the strange ultraviolet-absorbing substance swirling at the cloud tops? What happened to the oceans on Venus, and what triggered its runaway greenhouse?
. . Some clues may be found in understanding the role and amount of sulphur dioxide (SO2) in the atmosphere, said Dr Mills. When oxidized, it produces sulphuric acid, the main component of Venusian clouds and a tremendous greenhouse gas.
Oct 10, 06: Just a little more than a year ago, the small spot on Jupiter was a pale white; now it matches the reddish hue of its bigger sibling, the Great Red Spot, and boasts 400 mph winds, according to new data from the Hubble Space Telescope. It's probably picked up red material from lower in the Jupiter atmosphere, most likely some form of sulfur which turns red as part of a chemical reaction.
Oct 10, 06: "We thought Ceres had a flat surface", said Benoit Carry, from the Observatoire Paris-Meudon, "but our images show that it is rich in surface features." Carry's team has produced 360 infrared images of Ceres while observing it in rotation at the Keck observatory in Mauna Kea. The images are the first of an planetisimal/dwarf planet using infrared and advanced adaptive optics, a technique that uses deformable mirrors on a telescope to correct the blurring caused by turbulence in Earth's atmosphere. The success of the combined technique on Ceres recommends its use on other relatively small objects, such as the large planetisimal Vesta.
. . The Keck results also support Ceres' suspected oblate shape, which scientists say could be the result of as much as 25% water ice in it mantle. If so, the amount may be greater than all the fresh water on Earth.
. . The US space agency is preparing a spacecraft known as Dawn. It is set for launch next year and will use an ion engine to visit the planetisimal Vesta in 2011, and Ceres in 2015.
Sept 25, 06: It's not hard to sell attendees of the Space 2006 conference on permanent human settlements in space. For the futurists mapping the humans path to space, the destination makes all the difference in the world.
. . In low gravity, muscles atrophy and bones loose calcium and become brittle. Children --being adapted to the moon's one-sixth gravity or Mars' three-eighths gravity-- may not be able to function on Earth, Globus argues. That's a deal breaker, in Globus' opinion. The space researcher instead argues that rotating space stations that can produce near-Earth gravity would be the best bet for long-term human inhabitants. These stations could produce more energy because certain orbits could bring them more sunshine than is possible if they were land-based. And the stations would be hours away, rather than three days for the moon or, at best, six months for Mars. The proximity to Earth makes tourism a possibility and makes resupplying the stations a snap.
. . Robert Bigelow, a Las Vegas real estate and financial businessman that started Bigelow Aerospace in 1999, announced that he would put a space station in high orbit by 2012. However, creating a large enough space station to spin for artificial gravity is difficult enough that even the risk-taking businessman is not considering it. His scientists have instead drawn up plans for a module that can be created in space and planted on the moon to become the first part of a base.
. . Luna has gained adherents as the best initial settlement because the goal is attainable and scientists can use a moon base to study the long-term effects of low-gravity living on humans, said Klaus P. Heiss, executive director of High Frontier.
. . Heiss argues that a long-term moon settlement could develop the lion's share of the techniques necessary to survive for a long time on another planet, such as Mars, a planet with its own supporters. The Mars Society -- whose president, Robert Zubrin, literally wrote the book on the least expensive way to create a Mars base -- has been simulating the working conditions on Mars at its research station in the Arctic. Another proponent, the Mars Homestead Project, has created plans for building a base from mainly local resources. Glass, plastics and steel could all be made on Mars and having those resources makes Mars the best location for a long-term settlement, says Bruce Mackenzie, a co-founder of the project.
Sept 24, 06: Scientists have high hopes for Japan's Solar-B mission which has been launched from the Uchinoura spaceport. The spacecraft will investigate the colossal explosions in the Sun's atmosphere known as solar flares. These dramatic events release energy equivalent to tens of millions of hydrogen bombs in just a few minutes. The probe will attempt to find out more about the magnetic fields thought to power solar flares, and try to identify the trigger that sets them off.
Sept 19, 06: Scientific missions to the moon should concentrate on sampling its thin atmosphere and on examining as much of the lunar surface as possible, the
National Research Council advised today.
. . Human explorers should use robots and orbiters to help them scour the moon's surface, atmosphere and craters for clues about how our solar system formed and how life came about, the Council's Space Studies Board said.
Sept 18, 06: NASA needs to get ready as soon as possible to return to the moon, if for no other reason than to understand how life evolved here on Earth, the National Research Council urged.
. . "The moon is, above all, a witness to 4.5 billion years of solar system history, and it has recorded that history more completely and more clearly than any other planetary body. Nowhere else can we see back with such clarity to the time when Earth and the other terrestrial planets were formed", the report reads.
. . Most of the record of Earth's first few billion years has been destroyed by tectonic and geological process and even weather, so scientists have no direct evidence of how or when the atmosphere formed or precisely what factors went into the development and evolution of life.
Sept 18, 06: The Cassini spacecraft has discovered evidence of a vast ethane cloud on Saturn's moon Titan. Scientists believe flakes of ethane "snow" or drops of ethane "rain" may be falling from the cloud into lakes of liquid methane.
. . Before the mission, researchers expected to find the moon awash with oceans of liquid ethane. But so far, the evidence for them has been scarce, suggesting the ethane may be tied up as ice at Titan's poles. "We think that ethane is raining or, if temperatures are cool enough, snowing, on the north pole right now."
. . "By the end of next year, Cassini will have recorded the first polar temperature profile of Titan, which will tell us how cold conditions are at the pole." [JKH: I expect that, like Venus, the extreme air pressure/mass will mean that temps don't vary much, equator to poles.]
Sept 13, 06: A distant, icy rock whose discovery shook up the solar system and led to Pluto's planetary demise has been given a name: Eris, pronounced EE-ris. Eris' discoverer, Michael Brown of the California Institute of Technology, said the name was an obvious choice, calling it "too perfect to resist."
. . In mythology, Eris caused a quarrel among goddesses that sparked the Trojan War. In real life, Eris forced scientists to define a planet that eventually led to Pluto getting the boot.
. . Eris' moon also received a formal name: Dysnomia, the daughter of Eris known as the spirit of lawlessness.
. . Eris, which measures about 120 km wider than Pluto, is the farthest known object in the Solar system at 9 billion miles away from Sol. It is also the third brightest object located in the Kuiper belt. Brown nicknamed it "Xena" after the fictional warrior princess pending an official designation.
. . Eris is considered a dwarf planet as well. The most distant known solar system object from the Sun, it takes 557 years to complete an orbit. Brown said he plans to study Eris and Dysnomia further to figure out the dwarf planet's mass and density.
Sept 13, 06: Space "weather" in the upper reaches of the atmosphere is affected by weather conditions down here on Earth, a new study suggests.
. . The ionosphere is a layer off electrically charged gas, called "plasma", that blankets the Earth. It's formed when X-rays and ultraviolet rays from the Sun collide with and break apart atoms and molecules in the upper atmosphere. The densest part of the ionosphere forms two bands of plasma close to the equator about 370 km above the surface of the Earth.
. . Scientists think it works like this: Below the plasma bands, a layer of the ionosphere called the E-layer becomes partially electrified during the day. High-altitude winds blow electrically-charged plasma in the E-layer across the Earth's magnetic field, creating an electric field.
. . This electric field shapes the plasma above the E-layer into two bands. Therefore, anything that changes the motion of the E-layer plasma also affects the electric fields it generates; this in turn reshapes the plasma bands.
. . The images revealed four pairs of bright spots in the bands where the plasma was thicker than average. One of the pairs was located above the Pacific Ocean, but three of them were situated above the Amazon Basin in South America, the Congo Basin in Africa and Indonesia --areas with lots of thunderstorm activities.
Sept 11, 06: Pluto has been given a new name to reflect its new status as a dwarf planet. On Sept. 7, the former 9th planet was assigned the asteroid number 134340 by the Minor Planet Center (MPC), the official organization responsible for collecting data about asteroids and comets in our solar system.
. . Pluto's companion satellites, Charon, Nix and Hydra are considered part of the same system and will not be assigned separate asteroid numbers, said MPC director emeritus Brian Marsden. Instead, they will be called 134340 I, II and III, respectively.
. . There are currently 136,563 asteroid objects recognized by the MPC; 2,224 new objects were added last week, of which Pluto was the first. Other notable objects to receive asteroid numbers included 2003 UB313, also known as "Xena".
Sept 7, 06: The Cassini spacecraft is making a close flyby today. Researchers are curious to learn if molecules from Titan are escaping the atmosphere and perhaps coating the surfaces of neighboring moons. Nearby Iapetus, in particular, sports a half-dark face that may be covered in hydrocarbon gook from Titan. The other half of Iapetus is bright as snow.
. . The team will also be on the hunt for any temperature spikes recorded by Cassini's infrared detectors, which could provide evidence of volcanic activity. Cassini has found ice volcanoes on sister moon Enceladus. Scientists suspect a similar phenomena is underway on Titan, but so far have found no direct evidence of volcanoes.
Aug 30, 06: Ground controllers today successfully performed a major maneuver of
NASA's Mars Reconnaissance Orbiter (MOR)--an "end game" tactic that puts the orbiting probe a step closer to studying the red planet with its entire suite of science sensors. For months, the MRO has been aerobraking --using the friction of the planet's thin atmosphere to slow the craft. That technique saves on onboard propellant.
. . The decision to exit aerobraking was made early today. The burn gets MRO out of the atmosphere, with two more maneuvers scheduled over the next two weeks before the spacecraft achieves its science-gathering orbit.
. . One nagging item cropped up a few weeks ago. A radio frequency switch to flip between MRO's high and low-gain antennas is stuck. A tiger team of experts is investigating the issue, trying to ascertain the root, probable cause of the problem. "If we don't get the switch unstuck, we've lost some redundancy...but we still have the capability to communicate over the low and high-gain antennas using the other transmitter."
Aug 28, 06: Mars is home to the highest clouds ever discovered above the surface of a planet, astronomers said. The European Space Agency's orbiting Mars Express spacecraft found clouds that are between 80 to 100 km (50 and 62 miles) above the red planet. The highest clouds on Earth top out at about 84 km (52 miles).
. . The surprising clouds are most likely made of CO2, researchers said. There were detected with a camera that senses ultraviolet and infrared light, so there is no conventional picture of them.
. . The clouds were spotted by observing distant stars just before they disappeared behind Mars. The stars would dim as they went behind clouds.
Aug 24, 06: Pluto was stripped of its status as a planet today when scientists from around the world redefined it as a "dwarf planet", leaving just eight classical planets in the solar system.
. . In addition to the categories of "planet" and "dwarf planet", the definition creates a third category to encompass all other objects, except satellites, to be known as small solar system bodies.
. . The decision establishes three main categories of objects in our solar system.
. . * Planets: The eight worlds from Mercury to Neptune.
. . * Dwarf Planets: Pluto and any other round object that "has not cleared the neighborhood around its orbit, and is not a satellite."
. . * Small Solar System Bodies: All other objects orbiting the Sun.
Dwarf planets are not planets under the definition "Ceres is a dwarf planet. It's the only dwarf planet in the planetisimal belt", Brown said. "Charon is a satellite. Jupiter has 50,000 trojan planetisimals", which orbit in lockstep with the planet. Caltech's Mike Brown loses out in one sense. The Pluto-sized object his team found, called 2003 UB313, will now be termed a dwarf planet. "As of today, I have no longer discovered a planet", he said. But Brown called the result scientifically a good decision.
. . The category of "dwarf planet" is expected to include dozens of round objects already discovered beyond Neptune. Ultimately, hundreds will probably be found.
. ."For astronomers this doesn't matter one bit. We'll go out and do exactly what we did", Brown said. "For teaching this is a very interesting moment. I think you can describe science much better now" by explaining why Pluto was once thought to be a planet and why it isn't now. "I'm actually very excited."
Aug 24, 06: China and Russia plan to launch a joint mission to Mars in 2009 to scoop up rocks from the red planet and one of its moons, a Chinese scientist said. Russia will launch the spacecraft, while China will provide the survey equipment to carry out the unmanned exploration.
. . The probe, called Phobos-Grunt, will set off in October 2009 from the Baikonur cosmodrome on a Soyuz-2 rocket for Phobos, one of Mars' two tiny moons, to collect soil samples and bring them back to Earth. Polishchuk's three-year mission also aims to study the origins of Mars' moons and the atmosphere around the red planet, as well as monitor seasonal variations on the surface of Mars.
. . Phobos-Grunt --the word "grunt" in Russian means "soil" [groont (ground?)]-- resembles a giant spider and is made up of several globes with an attached drilling device. It weighs a total of around eight tons.
Aug 21, 06: The Sun has begun its next cycle of activity, part of an 11-year ebb and flow in sunspots and solar flares. Solar activity is near the low point in the cycle now. Few sunspots appear and solar flares are rare. But on July 31, a tiny sunspot appeared and then vanished after a few hours. It was a normal event, except that it was magnetically backward.
. . Astronomers think Cycle 24 could be a strong one based on historical records and computer projections. Enhanced activity means satellites and even power grids on Earth are at risk of electrical malfunction. Solar storms spew charged particles into space, and when they interact with Earth's protective magnetic field, electrical charges can dip into the lower atmosphere and even to the ground.
. . It will likely be many months and perhaps years before the new cycle builds steam and serious storminess ensues.
Aug 20, 06: Geysers spewing sand and dust hundreds of feet into the air have been discovered on Mars, scientists say.
. . Images from a camera orbiting Mars have shown the 100mph jets of carbon dioxide erupt through ice at the planet's south pole, Arizona State U says. The orbiting camera, called the Thermal Emission Imaging System (Themis), is on the Mars Odyssey probe.
. . The geyser debris leaves dark spots, fan-like markings and spider-shaped features on the ice cap. Geysers erupted when sunlight warming the ice turned frozen CO2 underground into high-pressure gas. "If you were there, you'd be standing on a slab of carbon dioxide ice."
Aug 17, 06: Luna started out very close to the planet but has been moving away ever since. It's currently drifting away 3.74 cm every year. For now, the system's barycenter is inside Earth. But that will change. The barycenter will eventually move outside the Earth as the Moon recedes.
. . None of this would occur for a few billion years. And Earth and the Moon would have to survive a host of remote catastrophe scenarios along with the predicted swelling of the Sun into a red giant, which might engulf and vaporize our planet.
Aug 16, 06: Peculiar spots, fan-like markings, and spider-shaped features on Mars' southern ice cap are seasonal formations, researchers announced. The shapes are formed by thin layers of dark dusty material that are sprayed by roaring jets of CO2 that erupt through the ice cap. This dusty material may also be the reason that the southern ice cap doesn't reflect much light.
. . The mystery markings, generally 17 to 50 meters wide, appear every southern spring as the Sun rises over the red planet's ice cap. They last about three to four months. The spots were nearly as cold as the CO2 ice, which along with water ice, make up the ice caps.
. . The whole process begins during Mars' frigid Antarctic winter, when temperatures drop to minus 128 degrees C. It's so cold that the Martian air --95% CO2-- freezes directly onto the surface of the permanent polar cap, which is made of water ice covered with layers of dust and sand. This layer of dusty CO2 frost re-crystallizes, becomes denser throughout winter and starts to slowly sink into the frost.
. . By spring, the frost layer becomes a slab of semi-transparent ice of about 3 feet thick, sitting on a layer of dark sand and dust. Sunlight passing through the slab reaches the dark material and warms it enough that the ice touching the ground turns directly to gas without going through the liquid phase. This process is called sublimation.
. . The warmed material produces a reservoir of pressurized gas under the slab, lifting it off the ground. The weak spots in the slab break through and high-pressure gas shoot up at speeds of about 150 kph carrying loose sand and particles into the Martian air, the researchers propose.
. . The large particles, too heavy to go far, land around the vents to make the spots, while the lighter sand grains blow downwind, creating the fans.
. . In a related study, the low reflectivity of the southern ice cap is also attributed to the dust in the region. Scientists initially thought this might be because the region is ice-free. But the mystery deepened when temperature measurements obtained the Thermal Emission Spectrometer (TES) on board the Mars Global Surveyor spacecraft revealed that this dark region was nearly as cold as the bright regions surrounding it, said lead study author.
. . The next thought was that the ice is so see through that the ground can be seen and thus there is reduced reflectivity. What we observed is that light rays don't penetrate deeply into CO2 ice, hence the "clear slab" idea must be revised, Langevin explained. What is needed is a layer of CO2 ice with heavy surface contamination by dust.
Aug 15, 06: Dozens of rocky bodies that are part of a sea of small rocky fragments never observed before have been spotted in the suburbs of our solar system beyond planet Neptune, thanks to a novel technique. These newly detected chunks of dust and rock coined Trans-Neptunian Objects (TNO) are smaller than 100 meters across. They are leftovers from the formation of planets.
. . Scientists had previously detected TNOs larger than 50 km across such as the Kuiper Belt Objects (KBO), a subset of TNOs. They suspected that there may be distant objects beyond Neptune since the 1940's, but it wasn't until 1992 that the second KBO was discovered (Pluto was the first). The rings of Uranus were first discovered during an occultation of a star by Uranus. But never have such small objects been detected this way.
. . Scientists didn't look for the reflected light this time. Examining data from NASA's Rossi X-ray Timing Explorer, they monitored the light from a background star, Scorpius X-1, as small objects moved in front of it in what are called occultations. Other than Sol, Scorpius X-1 is the brightest X-ray source in the sky. They found obvious dips in the light. Small TNOs are the most likely explanation. They identified 58 definite dips. "A 100-meter body only occults a background source for about 10 milliseconds and optical detectors cannot record light continuously at such small time intervals."
. . . Based on this finding, the researchers estimate that the number of TNOs reaches around a quadrillion, rather than the mere billions to a trillion as previously thought. This shows an extremely dense disk of material at the outer edges of the solar system mostly populated by smaller bodies.
Aug 1, 06: A string of robot spacecraft will shoot for Luna within the next two years, departing from Japan, China, India, as well as the United States. This multi-nation collection of science sensors and exploration gear will provide an extraordinary look at Earth's co-planet, setting the stage for a human return.
. . Four independent space probes are being readied for a lob toward lunar orbit: Japan's SELENE; China's Chang'E 1, India's Chandrayaan 1 and the U.S. Lunar Reconnaissance Orbiter. Meanwhile, the European Space Agency's (ESA) SMART-1, already in orbit around Luna, will be wrapping up its mission soon.
Aug 1, 06: Dust storms raging across the surface of Mars may wield toxic chemicals that could poison any forms of life as we know it on the planet's surface, according to two NASA-sponsored studies.
. . Small dust devils and planet-wide storms --combined with static electricity-- may lead to the formation of hydrogen peroxide and other corrosive chemicals that fall to the Martian surface as a sort of toxic snow.
. . Delory and his colleagues found that Martian dust storms, like their Earthly counterparts, can generate electric fields that rip apart water and carbon dioxide molecules in the planet's thin atmosphere. Those molecules would then be free to form hydrogen peroxide and other toxic oxidants that could scour the Martian surface of any organic molecules crucial for the formation of life.
. . A second study, led by University of Michigan researcher Sushil Atreya, found that the levels of hydrogen peroxide that could coalesce from Martian dust storms would be high enough to condense into snow that could blanket the surface below. [HO snow!] "As a consequence, any nascent life (microorganisms, ie) or even prebiotic molecules, would find [it] hard to get a foothold on the surface of Mars, as the organic material would have been scavenged by the surface oxidants."
. . The studies led by Delory and Atreya may help answer one long-lasting riddle of Mars exploration. NASA's two Viking landers found conflicting results when they tested Martian soil for signs of life in the mid-1970s. The landers added water and nutrients to Martian dirt to see if it contained any microorganisms. One instrument watched the nutrients as something broke them down, but another recorded no signs of organic matter in the Martian material.
. . The presence of hydrogen peroxide or ozone in the Mars dirt could have fooled the Viking instruments by producing reactions similar to that expected from microorganisms, researchers said, adding that the substance could also break down methane seen in the Martian atmosphere.
. . [Apparently, there was a runaway static effect. Maybe the ecology would be more stable than thot --if we can get past that effect. So terraforming the place would first involve stopping the static. So stop the dust. Drop a lil comet onto the surface.]
July 28, 06: It has methane rain and white crystalline sand dunes, and now scientists say Saturn's moon Titan also has several dozen lakes. The lakes are probably made up of methane, with a little ethane mixed in.
. . During the flyby, Cassini's radar spotted several dozen lakes, including one about 60 miles long. Some of the new radar images show channels leading in or out of a variety of dark patches. The shape of the channels also strongly implies they were carved by liquid. "We've always believed Titan's methane had to be maintained by liquid lakes or extensive underground 'methanofers', the methane equivalent of aquifers. We can't see methanofers."
. . This was Cassini's first look at the region. It's radar, which penetrates the smog, was used to find the lakes. Lakes should change shape slightly with the seasons, and winds ought to roughen their surfaces, so future passes by Cassini will look for these effects.
. . Other Cassini observations have revealed apparent river channels elsewhere on the moon, as well as shorelines that might represent lakes or seas. Saturn has at least 47 moons.
July 26, 06: The weather forecast for Saturn's giant moon Titan calls for methane rain; from a persistent drizzle that keeps the surface of Saturn's largest moon damp to fierce storms that could produce huge droplets.
. . July 24, 06: Scientists have found the first widespread evidence of giant hydrocarbon lakes on the surface of Saturn's planet-size moon Titan. The cluster of lakes was spotted near Titan's frigid north pole during a weekend flyby by the international Cassini spacecraft, which flew within 900 kms of the moon. If confirmed, Titan would become the only planetary body other than Earth known to host lakes.
. . Researchers counted about a dozen lakes 10 to 100 km wide. Some, which appeared as dark patches in radar images, were connected by channels, while others had tributaries flowing into them. Several were dried up, but the ones that contained liquid were most likely a mix of methane and ethane.
. . Last year, Cassini found what appeared to be a liquid hydrocarbon lake about the size of Lake Ontario on Titan's south pole. But the recent flyby marked the first time the spacecraft spied a multitude of lakes. [NOT water. But I wonder... would water-ice bergs float in liquid methane?!]
. . In some cases, rims can be seen around the dark patches, suggesting deposits that might form as liquid evaporates. The lakes are thought to be filled by rainfall, perhaps in seasonal storms.
July 20, 06: New radar images of Saturn's moon Titan reveal dunes, hills, valleys and rivers that scientists say look a lot like home. But on Titan, which is frigid and shrouded in smog, the features are likely carved in ice rather than solid ground.
. . The detailed view is of a bright area on Titan called Xanadu. It's about the size of Australia and has been studied from afar for years. Now scientists are getting a better look with NASA's Cassini spacecraft. Radar is bounced off the surface to generate an image that cannot be made using visible-light observations because the orbiting spacecraft can't see through the moon's thick atmosphere.
. . The observations reveal mountains about as high as the Appalachians. The river channels are likely carved by liquid methane or ethane, as the moon is too cold for water to be liquid.
July 18, 06: A single dose of radiation approaching what will be faced by long-term space travelers to Luna or Mars causes as much as a 39% spongy bone loss in mice, a new study shows.
. . The loss of connectivity in spongy bone ranged as high as 64% for one of the types of radiation tested, along the lines of an osteoporosis diagnosis. The results say nothing directly about the effect of space radiation on people but it has implications for the future of human spaceflight, especially given the U.S. commitment to send astronauts on long trips beyond low-Earth orbit. Both mice and humans lose bone after radiation exposure. "We were surprised that there was bone loss, and the degree was a lot more than we expected."
. . The gamma, proton, carbon and iron radiation used in the experiment is less damaging than the complex mix of radiation (protons and heavy ions, or ionizing radiation) that long-term space travelers will experience.
. . Bone is comprised of hard or cortical bone on the outside and marrow inside, as well as bone adjacent the marrow, called trabecular bone. This spongy part of the bone is key to bearing weight and preventing fractures. In the experiment, radiation had no real effect on cortical bone.
. . Trabecular bone connectivity is irreplaceable, once lost. "You can regain bone mass, but once the connections between struts is lost, the load is not being passed from strut to strut and that becomes permanent. Struts can become larger and thicker but loads are not transferred as efficiently once you've lost the connections between struts."
. . The new study shows that on longer flights, such as a 6-month trip to Luna or 30-month trip to Mars, the bone lost as a result of microgravity will be compounded by more extensive bone loss as a result of radiation exposure. Up to now, NASA has focused on radiation's cancer-causing properties and effect on the central nervous and immune systems. The effect on bone health has been unexamined.
. . [OOPS] Procter and Gamble, which makes an osteoporosis drug called Actonel, helped to support the research.
From new measurements: Luna is spiraling away from Earth at a rate of about 1.5 inches a year, due to ocean tides on Earth. Another discovery is that the moon probably has a liquid core.
July 10, 06: China has successfully tested a new rocket engine to power the country's ambitious program of manned space flights and moon landings, the official Xinhua news agency reported.
July 5, 06: NASA's rocket scientists have a new appreciation for the out-of-this-world power of bird droppings. The orbiting Discovery sported some whitish splotches on its black right wing edge that NASA officials said appeared to be bird droppings.
. . Shuttle lead flight director Tony Ceccacci said he saw the same splotches on the identical part of the shuttle about three weeks ago when Discovery was on the launch pad and laughed when pictures beamed back from space Wednesday showed they were still there.
July 5, 06: NASA needs to rethink its Mars exploration plans after 2010 given new understandings about the red planet and likely funding levels in the coming years, according to a report just out from a panel of outside experts.
. . In a letter to Mary Cleave at NASA Headquarters, the chair of the assessment, Reta Beebe of New Mexico State University, offered a set of recommendations to NASA, including:
. . * Add a Mars Long-Lived Lander Network in the mix of options for launch in 2016;
. . * Consider delaying the launch of the Astrobiology Field Laboratory until 2018;
. . * Devise a strategy to implement the Mars Sample Return mission;
. . * Ensure that the primary role of the Mars Science and Telecommunications Orbiter (MSTO) is to address science questions, and not simply to serve as a telecommunications relay; and
. . * Move forward on 'Mid Rovers,' wheeled robots more capable than Spirit and Opportunity but less complicated, not as expensive, and not as heavy as the Mars Science Laboratory to be launched in 2009.
June 26, 06: A space telescope scheduled for launch in 2007 will be sensitive enough to detect theoretical miniature black holes lurking within our solar system, scientists say.
. . By doing so, it could test an exotic five-dimensional theory of gravity that competes with Albert Einstein's General Theory of Relativity. That is, of course, if the tiny black holes actually exist.
. . The Randall-Sundrum braneworld model, named after the scientists who created it, states that the visible universe is a membrane embedded within a larger universe, like a strand of seaweed floating in the ocean. Unlike the universe described by General Relativity-which has three dimensions of space and one of time-the braneworld universe contains an extra fourth dimension of space for a total of five dimensions. [rather than the string-theory's ten-plus]
. . Thousands of them should exist in our solar system. General Relativity, in contrast, predicts that such primordial black holes evaporated long ago. The researchers predict that braneworld black holes are about the size of an atomic nucleus but have masses similar to that of a tiny planetisimal.
. . Petters and Keeton say their theory is testable. The mini-black holes should warp the fabric of space-time differently from other types of black holes-thos of stellar-mass and the supermassive variety-due to their close association with the fifth dimension. Light, specifically gamma-rays, should be distorted differently when they whiz past braneworld black holes compared to conventional black holes.
June 26, 06: A planetisimal possibly as large as a kilo in diameter is rapidly approaching the Earth, & will pass just beyond Luna's average distance from Earth. Analysis of its orbit has ruled out any future collision. Based on its brightness, the diameter is believed to be somewhere in the range of 410 to 920 meters.
. . 2004 XP14 is a member of a class of planetisimals known as Apollo, which have Earth-crossing orbits. There are now 1,989 known Apollos.
. . On April 13, 2029, observers in Asia and North Africa will have a chance to see another planetisimal, but without needing a telescope. planetisimal 99942 Apophis, about 300 meters wide, is expected to be visible to the naked eye as it passes within 32,000 km. Astronomers say a planetisimal that large comes that close about once every 1,500 years.
. . Radar measurements of the exact distance and velocity of the planetisimal will allow for precise information on its orbit. From this scientists can also discern details of the planetisimal's mass, as well as a measurement of its density, which is a very important indicator of its overall composition and internal structure.
June 21, 06: Nix and Hydra, the pair of moons orbiting Pluto, were officially christened by the International Astronomical Union. The Hubble Space Telescope spotted the two satellites --more than twice as far away as Charon and many times fainter.
June 20, 06: A new idea is to capture a relatively small planetisimal -—perhaps 30 meters wide-- by sending a robot to it. The robot would heave material from the planetisimal's surface into space at high speed, and the reaction force would gradually direct the planetisimal to a Lagrange point, one of a handful of nodes along Earth's orbit where the gravity of Earth and the Sun balance out. Scientists know that object can be kept stable at a Lagrange point with little or no energy.
. . The captured rocky weapon would be held there, traveling around the Sun ahead of or behind the Earth, held until needed. Then, if a large planetisimal threatens to hit us, the small one is moved into its path, using the same heaving technique. The rocks collide, and the big one is broken into somewhat less harmless bits. The collision disperses the fragments of the incoming planetisimal, so that not all of them hit the planet.
. . But … Depending on the relative masses of the two objects, between 10 and 20% of the incoming planetisimal mass would still hit, "but the fragments would be dispersed all over the Earth and, hopefully, none would be large enough to reach the ground with a large remaining destructive power", said Didier Massonnet of the CNES research center in France.
. . The collision should be engineered to occur at least 1 million km from Earth and would take about eight months to execute from the Lagrange point.
. . One small planetisimal that could fit the bill already been identified; it is called 2000 SG344, and Massonnet suspects there are many others that would work.
. . Material mined from a small, nearby planetisimal could provide liquid oxygen for other space missions more efficiently than mining it from the Moon, which other researchers have proposed. Liquid oxygen could be used as fuel at a cosmic gas station that would allow spacecraft to be launched from Earth with much smaller tanks and therefore more cheaply.
. . Other researchers have suggesting mining planetisimals for their metals. "Several thousands of tons of oxygen might become available sitting on the outer rim of Earth's gravity field", the researchers write.
June 20, 06: The space above you is fizzing with activity as bubbles of superhot gas constantly grow and pop around Earth, scientists announced. Astronomers found the activity up where Earth's magnetic field meets a constant stream of particles flowing out from the Sun. While space is commonly called a vacuum, in fact there is gas everywhere, albeit not as dense as the air on Earth, or even Luna!
. . The newfound bubbles are technically called density holes. In them, gas density is 10 times lower. The gas in the bubbles is 18,000,000 Fahrenheit (10,000,000 Celsius) instead of the 180,000 degrees Fahrenheit of the surrounding hot gas, which is known as plasma.
. . The bubbles were found in data collected by the European Space Agency's Cluster mission, a flotilla of four spacecraft. Researchers first thought they had an instrument glitch when the spacecrafts passed through bubbles.
. . The bubbles expand to about 1,000 km and probably last about 10 seconds before bursting and being replaced by the cooler, denser solar wind. It is not known for sure how the bubbles are created, but the researchers suspect it involves the solar wind colliding with the magnetic field.
The smallest Earth-crossing asteroid, 3554 Amun, is a 2,000-meter lump of iron, nickel, cobalt, platinum, and other metals; it contains 30 times as much metal as Humans have mined throughout history, although it is only the smallest of dozens of known metallic asteroids and worth perhaps US$ 20 trillion. eg, Iron Meteorite: Iron 91%, Nickel 8.5%, Cobalt 0.6%. Stony Meteorite: Oxygen 36%, Iron 26%, Silicon 18%.
June 16, 06: The Martian atmosphere is vastly thinner than Earth's --the distance between molecules is 120 times as far.
. . Scientists from Penn State University set up a computer simulation to figure out how far a sound wave would travel in Mars' thin air. On Earth, the sound from an average scream might travel about a km, depending on conditions. But it would only make it about 17 meters on Mars.
. . Your voice would be lower [until you died]. It's the reverse of talking like a chipmunk after inhaling helium. Helium gas has a higher speed of sound than the air we normally breathe, which causes our voices to sound a few octaves higher.
June 14, 06: Here's a prime location for the next Mars rovers to investigate. The northern polar cap of Mars sprawls across the top of the Red Planet for roughly 1,000 km. It's 2.7 km high, max --thinner on the rough edges, where deep canyons and smaller troughs carve a spiraling pattern into the cap.
. . Near one edge of the northern polar cap is a curious feature named Udzha. It's 45 km across, thot to be a crater, almost hidden from view. Its rim peeks from under the polar cap's layers.
. . Each polar winter sees an accumulation of CO2 frost, which falls as light snow, condensing directly from the thin cryogenic atmosphere -- minus 130 degrees Celsius (minus 202 F). This produces a thin north "polar cap" that reaches down to about latitude 60 degrees. When the frost disappears the following summer, it leaves the dust behind, along with the water ice.
August 05: discovery of the first triple asteroid system, 87 Sylvia, much closer to the sun in the main asteroid belt between Mars and Jupiter. They were able to chart their orbits of to estimate the density of Sylvia, from which they concluded it is a rubble-pile of loosely packed rock. Diameter: 384 x 264 x 232 km.
June 14, 06: Astronomers have detected three new rocky bodies which share the same orbit as Neptune as it travels around the Sun. The finding brings the total number of the gas giant's asteroid companions, or "Trojans", up to four.
. . The highly inclined orbit of one of them supports the hypothesis that the Neptune Trojans were captured from a much larger asteroid "cloud" that surrounds the planet, and that they are not the broken remains of some larger object as some scientists have speculated.
. . The Trojans gather around one of Neptune's two so-called "Lagrangian" points. [actually, there are 5 in any 3-body system --nearly all at L4 & L5.] In these regions --located 60 degrees in front of and behind the planet in its orbit-- the Sun and Neptune's gravity combine to ensnare passing objects. The orbit of one of the new Trojans is tilted about 25 degrees relative to the plane that Neptune orbits the Sun, compared to only about 5 degrees for the other three Trojans.
. . The way the survey was set up, it was very unlikely that such a highly inclined object would be detected. The fact that it was indicates that there are at least as many highly inclined Trojans low inclination ones . far from the solar system plane, said study team member.
. . [I'll try to keep up w the total. The "Hill Sphere" is less a sphere than a ring. It is at the distance where all Trojan areas are found. The 5 flattened-oval regions center on the LaGrange-points. L4 is 60° preceding the planet and L5 is 60° following. Because there are perturbations, bodies at the L1, L2 and L3 points will wander away over time: only the L4 and L5 points are stable.
. . Why don't they coagulate over billions of years, & form one body?!
. . Amazing! The Jupiter Trojan clouds have about as many objects in total as the main planetisimal belt. Number of objects at Jupiter's L4 point = 1128 --number of objects at the L5 point = 921. ...as of June 17, 06.
. . Neptune's Trojan clouds are probably more populated than the Jupiter Trojan clouds [!!] but because of Neptune's extreme distance from the Sun, the Neptune Trojans are harder to detect.]
June 14, 06: Massively parallel computing simulations have modeled how much explosive power it would take to destroy or sidetrack an asteroid that's got Earth in its cross-hairs. For the computer runs, asteroid 6489 Golevka was chosen. Golevka isn't going to hit the Earth. It was used as a "proxy" because solid geometry data about the object existed.
. . Keeping tabs on Golevka has helped pin down the Yarkovsky Effect --a miniscule amount of force produced as the asteroid absorbs energy from the Sun and re-radiates it into space as heat. Over time --lots of it-- that force can have a big effect on an asteroid's orbit.
. . There are two "end-member strategies" in the Golevka work:
. . * Deflection: Keeping the asteroid in one piece and changing its trajectory to miss the Earth; and
. . * Disruption: Blowing it to smithereens and making sure all the bits miss the Earth.
. . "There are a range of in-between options", Boslough told SPACE.com, "but the deflection end of the spectrum is much more realistic." On a kiloton-per-kiloton basis, small, shallow explosions are much more effective for moving the asteroid than large, deep ones. Using multiple, low-yield, deflecting explosions is much better than using one high-yield device.
. . "There are many advantages" to this approach, Boslough observed. "For one, you don't need to rendezvous with the asteroid and drill a hole or otherwise place a device. You can set it off as a surface burst. Contrast the time it takes to 'land' something on the surface of an asteroid --like NASA's Near Earth Asteroid Rendezvous (NEAR) spacecraft-- to how long it takes just to get there, like NASA's Deep Impact", he said.
Phobos is an oblong, potato-shaped object.
June 13, 06: It is set to become one of the key experiments on ExoMars, Europe's next mission to the Red Planet in 2011.
. . The Life Marker Chip (LMC) will test soil samples drilled from below Mars' surface for specific molecules that can be associated with life. A UK-led international consortium is developing the technology. The results might not be a definitive proof of the existence of microbes, but they could still provide tantalizing evidence for their possible presence.
. . The £410m (600m euros) European Space Agency project (Esa) was approved by ministers last December. The current vision is for a 180kg rover that would study Mars' environment and geology. It would also carry a range of instrumentation capable of investigating the planet's life potential - past and present. The LMC would be a key component of ExoMars' "Pasteur Laboratory".
. . The Life Marker Chip will look for the presence of molecules such as amino acids, the building blocks of proteins; and adenosine triphosphate, the critical molecule involved in energy transfer in cells. To make a detection, the ExoMars rover would drill down into the Martian soil with a mole and pull a sample into the Pasteur housing. There, the sample would be ground up and treated with solvents to pull out any organic material. The fluid would then be passed through a test channel in the LMC. It's similar to pharmacy testing kits that detect the presence of a hormone associated with the early stages of pregnancy.
June 10, 06: In 1999, MIT engineering Professor David Miller showed Star Wars on the first day of class. During the scene where Luke Skywalker practices his light saber against a seeker remote, Miller stood up and said "I want you to build me some of those."
. . The SPHERES mini-satellite, a tiny (eight-inch diameter) remote-controlled device, flew in the Space Station. SPHERES stands for Synchronized Position Hold Engage and Reorient Experimental Satellites.
. . The demonstration tested the basics of formation flight and autonomous docking that should be useful in future multiple spacecraft formation flying. The long-range plan for SPHERES is to test flying in formation with a set of mini-satellites. The first test flight consisted of a series of 10-15 pre-planned maneuvers lasting up to 10 minutes each. Once the appropriate software was loaded on the controlling laptop, the satellite began a set of pre-programmed maneuvers to test attitude control, station keeping, re-targeting, collision avoidance and fuel balancing. The mini-satellite is manuevered using compressed carbon dioxide gas thrusters.
. . The next step in the official testing is to tuck additional SPHERES units onto shuttle flights to test formation flying. The second satellite is scheduled to launch to the station on STS-121 in July 2006. The third will be launched on STS-116.
June 10, 06: A planetisimal that has been corkscrewing around Earth in recent years is heading for deep space today. It arrived in Earth's vicinity 1999. The rock is relatively small and is not a threat.
. . "We believe 2003 YN107 is one of a whole population of near-Earth planetisimals that don't just fly by Earth", Chodas said. "They pause and corkscrew in our vicinity for years before moving along."
. . These planetisimals are called Earth co-orbital planetisimals or "co-orbitals." They share Earth's orbit, circling the Sun in almost exactly a year. They can catch up to Earth from behind or Earth can catch them. "These planetisimals are not truly captured by Earth's gravity, but from our point of view, it looks like we have a new moon."
. . At least four small planetisimals behave similarly: and 2001 GO2, 2002 AA29, 2004 GU9 and 2003 YN107. More likely exist but await discovery by improved search technology. And an object known as Cruithne is trapped in a suspended state around Earth for at least 5,000 years.
. . The corkscrew path of 2003 YN107 is lopsided and today it will dip within 3.4 million km of Earth, slightly closer than usual. Earth's gravity will then give it a slingshot and send it on its way. Luna is 238,900 miles miles away.
. . In about 60 years, it will lap Earth again, resuming its role as a temporary, corkscrewing moonlet. [By then, we'll be ready to mine it --or another that's hangin' around.]
. . An unusual arrangement, in which close encounters with a planet do not result in impacts or strong distortion of the asteroids orbit is termed a "horseshoe" orbit because of its shape. Note that the asteroid doesn't go around the Earth, but rather shares the Earth's orbit with it.
. . Another way to think of this horseshoe is to consider a three-lane, circular race track. The Earth is a large truck moving at a constant speed down the centre lane and the asteroid is a car. When in the outer lane, the car is going a bit slower than the truck, and the truck starts to catch up. But just when the truck is about to pass, the car switches to the inner lane and speeds up. It then starts to pull away from the truck, but because the track is circular, the car will eventually catch up with the truck from behind. When it gets close, the car again switches to the outer lane and slows down. Then the whole cycle repeats. This is what is happening in a simple horseshoe. Both vehicles share the same highway, but in a coordinated fashion so as to avoid collision. In reality, the delicate coordination of the asteroid and the Earth is performed by the laws of celestial mechanics, and requires just the right conditions.
June 5, 06: Astronomers on Earth will have ringside seats to a face-off between two of the biggest storms in the solar system. In one corner will be Jupiter's Great Red Spot, a behemoth of a tempest that is twice as large as Earth and whose 550 kph winds have been whirling for hundreds of years.
. . Its contender will be Oval BA, also known as "Red Jr.," a young six-year storm that is only half Great Red's size but whose winds are just as fierce. The two are approaching each other now and are expected to have their closest approach on the Fourth of July. it's anybody's guess what will happen when they do. In fact, the two storms typically pass each other every two years or so.
June 5, 06: A rock carving discovered in Arizona might depict an ancient star explosion seen by Native Americans a thousand years ago, scientists announced. If confirmed, the rock carving, or "petroglyph" would be the only known record in the Americas of the well-known supernova of the year 1006.
. . The carving was discovered in White Tanks Regional Park just outside Phoenix, in an area believed to have been occupied by a group of Native Americans called the Hohokam from about 500 to 1100 A.D.
. . Although nearly invisible today, the supernova of 1006, or SN 1006, was perhaps the brightest stellar event ever to occur in recorded human history. At its peak, the supernova was about the quarter the brightness of the Moon, so radiant that people could have read by its light at midnight.
June 2, 06: Scientists and science fiction fans alike have big plans for carbon nanotubes; it has been hoped that a cable made of carbon nanotubes would be strong enough to serve as a space elevator. However, recent calculations by Nicola Pugno of the Polytechnic of Turin, Italy, suggest that carbon nanotube cables will not work.
. . American engineers worked on the problem in the mid-1960's. What type of material would be required to build a space elevator? According to their calculations, the cable would need to be twice as strong as that of any existing material including graphite, quartz, and diamond.
. . In something of a "downer" for space elevator fans, Pugno has calculated that inevitable defects will greatly reduce the strength of any manufactured nanotubes. Laboratory tests have demonstrated that flawless individual nanotubes can withstand about 100 gigapascals of tension; however, if a nanotube is missing just one carbon atom, it can reduce its strength by as much as 30%. Bulk materials made of many connected nanotubes are even weaker, averaging less than 1 gigapascal in strength.
. . In order to function, a space elevator ribbon would need to withstand at least 62 gigapascals of tension. It therefore appears that the defects described above would eliminate carbon nanotubes as a usable material for a space elevator cable.
June 1, 06: A Japanese spacecraft that landed on an asteroid found a ball of rubble held loosely together by its own gravity, unlike other asteroids that have been visited, according to reports today. The spacecraft Hayabusa, whose name means "falcon" in Japanese, hovered over the near-Earth asteroid Itokawa last autumn, taking several measurements before landing briefly on the orbiting gravel pile. Itokawa has two parts resembling the head and body of a sea otter.
. . Previously studied asteroids appeared to be lumps of solid rock, but Itokawa is made up of loosely packed bits of sand and boulders, they said. Their findings could have implications for deflecting asteroids that might pass too closely to the Earth in the future.
. . The little spacecraft, now bringing a capsule of samples back to Earth, uses an electronic ion propulsion system, whose efficiency should be critical to future missions in deep space. "Its hydrazine (fuel) had leaked away shortly after the second sample collection attempt. Two of the reaction wheels had failed and the battery was dead. Adding insult to injury, Minerva --intended to be the first asteroid surface robot-- had been released during an unexpected maneuver and was lost to space."
June 1, 06: Saturn's moon Enceladus might have rolled over on its side sometime in the past, a suggestion that would account for a strange finding made by the Cassini spacecraft.
. . The moon has a hot spot at its south pole, an area of low density where water vapor shoots into space, Cassini discovered. Heat from within is likely created by the varying tugs of Saturn’s gravity as Enceladus' distance from the giant planet changes during the course of its orbit.
. . But why is there a hot spot only at the south pole? Nimmo and colleagues explain that hot material from within Enceladus welled up in one location. Hot material expands and is less dense. Like all rotating bodies, the moon would be more stable if low-density areas were at the poles and regions of high density were at the equator. So the moon reoriented itself in that manner, the thinking goes.
. . There is a way to possibly confirm that the moon flipped. Its former leading hemisphere should have had more impact craters than the trailing hemisphere. If it flipped 90 degrees, the pattern of craters now present would reveal as much.
May 30, 06: Streamers of debris appear to connect Saturn's tiny moon Prometheus, just 102 km across, to the planet's F ring. Interactions between the moon and ring material create the rippled pattern the Cassini spacecraft imaged here.
Does Pluto have rings? After Alan Stern's team discovered Pluto's small moons, they realized impacts on them might generate ejecta that gets into orbit around Pluto, creating rings around the planet. Rings have so far been discovered only around our solar system's gas-giant planets.
May 30, 06: Enceladus: why is geologic activity is currently limited to the southern pole? The density of surface craters show that geologic activity has been present on Enceladus for more than 4 billion years, according to Porco, but the surfaces at the south are as young as a half a million years.
. . Remnants of old craters remain on most of the planet, but the southern pole is “littered” with house-sized ice boulders, “straddled” with 130-kilometer-long fractures and nearly free of craters, Porco and colleagues wrote. One possibility is that a nonuniform interior — created by the moon’s original formation, subsequent tectonics, gravitational forces or some other process — concentrates heating at the southern pole.
. . A gravity survey of the moon could help “nail down” where water might exist in its interior.
May 28, 06: The US space agency's rovers will get a software upgrade to allow them to make "intelligent" decisions in the study of Martian clouds and dust devils.
. . The new algorithms will give the robots' computers the onboard ability to search through their images to find pictures that feature these phenomena. Only the most significant data will then be sent to Earth, maximizing the scientific return from the missions.
. . Nasa says its robotic craft will become increasingly autonomous in the future. "An instrument can acquire considerably more data than can be down-linked --this is a recurring theme on all spacecraft."
. . The agency's Mars Odyssey orbiter, which has been mapping the Red Planet since 2001, will get new autonomous flight software later this year. This will give the satellite the ability to react to sudden changes on the Martian surface. It will be "tuned" to look for temperature anomalies, rapid changes in the polar caps, the emergence of dust storms and the formation of water-ice clouds.
. . If its algorithms mark an event of interest, the spacecraft will be able to break into its routine and take more images, without waiting for commands from Earth. Scientists say this will capture short-lived, but highly significant, events that might otherwise have been missed.
. . Self-reliant spacecraft would open up new opportunities on far-distant missions, where probes might be out of contact with Earth for hours or even days at a time. Lorenz envisages the next craft on Titan to be a blimp that could fly itself around and select the most interesting locations to set down to do investigations.
Rate at which solar neutrinos reach Earth: 60 billion per square centimeter per second.
May 24, 06: A strikingly simple concept would provide efficient water provisions for human outposts/bases on the Moon. The idea is to repeatedly clobber our already crater-rich neighbor with tons of water ice --to establish an "anywhere, anytime" delivery system.
. . Not only could chucking a payload of water ice to the Moon help sustain an expeditionary crew there, the impact mimics--in experimental form--a comet strike. Therefore, it's a double-whammy: A science mission wrapped within an exploration capability test mission.
. . SLAM needs no mid-course correction en route to the Moon, nor a spacecraft for that matter. All that's necessary is a thermal jacket for the water ice payload that's flung by rocket booster toward any selected spot on the Moon. At lunar impact speeds, virtually all of the ice will come to rest less than 1.5 meters below the surface if properly pre-fractured. Also, work done on the concept indicates that a majority of the water ice that is slammed into the Moon is retained, with only 15% vaporized.
. . One constraint is that an Earth-to-Moon ice ball strike must take place during lunar night, he said, with mining recovery necessary before sunrise to prevent ice sublimation after impact.
May 23, 06: Voyager 2 could pass beyond the outermost layer of our solar system, called the "termination shock", sometime within the next year, NASA scientists announced. The milestone, which comes about a year after Voyager 1's crossing, comes earlier than expected and suggests to scientists that the edge of the shock is about one billion miles closer to the Sun in the southern region of the solar system than in the north.
. . This implies that the heliosphere, a spherical bubble of charged low-energy particles created by our Sun's solar wind, is irregularly shaped, bulging in the northern hemisphere and pressed inward in the south. Scientists determined that Voyager 1 was approaching the termination shock when it began detecting charged particles that were being pushed back toward the Sun by charged particles coming from outside the Solar System.
. . The researchers think that the heliosphere's asymmetry might be due to a weak interstellar magnetic field pressing inward on the southern hemisphere. "The [magnetic] field is only 1/100,000 of the field on the Earth's surface, but it's over such a large area and pushing on such a faint gas that it can actually push the shock about a billion miles in."
May 22, 06: A large telescope that will scan the entire visible sky every three nights is to be built on a mountain in Chile. The 8.4m Large Synoptic Survey Telescope (LSST) will be 50 times as powerful as other survey telescopes. The observatory will be able to produce color movies of objects that change or move on rapid timescales. It will join the existing Cerro Tololo Inter-American Observatory, on Cerro Pachon, an 2,640m mountain peak in northern Chile. The LSST should be under construction by 2009 with a planned completion date in 2012.
Mars is 700 billion billion tons of iron and rock, wrapped in an unfamiliar landscape of canyons, craters and calderas. Nonetheless, the most compelling thing we could find on this enormous, orange orb would be a microgram of wet chemistry able to reproduce, move, grow, and evolve.
May 18, 06: Farnetta believed that we should colonize Luna first. "The moon is infinitely easier, oxygen is locked up in the soil, but no hydrogen. You could bring that off of the earth." He praised the abundance of silicon, and said "you could make glass and glass composite. You could even build huge structures at the lagrange points around the moon with variable gravity."
. . Musk was skeptical, comparing the moon to the arctic, and asking why Europeans never colonized the north, but instead put their energy into the new world. "It took a lot of effort to cross the Atlantic and to colonize the US. [The moon is] not a great place to found a new country. First, the gravity is much less. There's no atmosphere on the moon, and some on Mars. Mars also has all the chemicals you need, including water." He went on to characterize the moon as a little barren rock with hardly any gravity, while praising Mars' 24.5-hour day. He concluded by saying that "although Mars is very far away, it takes about the same energy to get there."
. . When asked about another possible way to get into space, the space elevator, both were dismissive. "The main component is made out of Unobtainium," joked Farnetta. Musk agreed. "We want to see a carbon nanotube footbridge," he warned, "before we see one 60,000 miles long."
May 5, 06: The color of Pluto’s two recently discovered satellites are essentially the same neutral color as Pluto’s large moon, Charon, scientists said. Charon’s surface is known to consist primarily of water ice, so the similar colors of P1 and P2 suggests that these moons have water ice surfaces, too.
. . The finding supports the theory that all three of Pluto’s moons were formed from a single giant impact that took place about 4.6 billion years ago. Recent observations about the orbital motions of Pluto’s recently discovered moons, P1 and P2, also support this theory.
. . Pluto’s surface, in contrast, has a reddish hue, which is believed to be the result of interactions between sunlight and nitrogen and methane surface ices.
May 10, 06: Neptune's largest moon, Triton, was originally a member of a duo orbiting the Sun but was kidnapped during a close encounter with Neptune, a new model suggests.
. . Triton is unique among *large moons in that it orbits Neptune in a direction opposite to the planet's rotation, which long ago led scientists to speculate that the moon originally orbited the Sun. But until now, no convincing theory for how Triton paired with Neptune existed.
. . "We've found a likely solution to the long-standing problem of how Triton arrived in its peculiar orbit", said Craig Agnor, a researcher from the University of California, Santa Cruz. "In addition, this mechanism introduces a new pathway for the capture of satellites by planets that may be relevant to other objects in the solar system."
. . The new model predicts that Triton came from a binary setup much like Pluto and its moon, Charon.Binary systems can be pulled apart by gravitation when they encounter large planets like Neptune. The orbital motion of the binary system causes one member to move slower than the other, which can disrupt the system and permanently change the orbital companion.
. . This mechanism, known as an exchange reaction, could have delivered Triton to any of a variety of different orbits around Neptune, Agnor said.
May 10, 06: A large fragment of an "aster"oid that punched 160km wide (100 miles) hole in the Earth's surface has been found. The beachball-sized fossil meteorite was dug out of the 145-million-year-old Morokweng crater in South Africa. It is a unique discovery because large objects are widely believed to completely melt or vaporize as they collide with the planet. A 10-km-diameter impactor is thought to generate temperatures of between 1,700-14,000 C.
. . The Morokweng crater is one of the largest on Earth, and was formed at the boundary of the Jurassic and Cretaceous periods. Created by an asteroid measuring about 5-10km (3-6 miles) in diameter, the impact bowl lies hidden beneath the sand of the Kalahari Desert.
. . "What is amazing is that here we have these fragments --that may not have been attached to the asteroid, or maybe trailing behind it-- that smashed into the Earth and survived the fiery furnace in the crater that formed; and then they got trapped."
May 8, 06: When Hurricane Katrina slammed into the United States in August of last year, it became a deadly, destructive, and costly episode --one that has also become a metaphor for lack of government action, both pre- and post strike.
. . At the current time, there is no agency of the U.S. government --nor of any government in the world-- with the explicit responsibility to develop and demonstrate the technology necessary to protect the planet from near-Earth object (NEO) impacts.
. . The U.S. Congress needs to be encouraged to take a step in demonstrating the ability to deflect a menacing NEOs believes former NASA astronaut, Russell Schweickart, Chairman of the B612 Foundation. He presented an update today on dealing with troublesome asteroids here at the 25th International Space Development Conference. The goal of B612, a confab of scientists, technologists, astronomers, astronauts, and other specialists is to significantly alter the orbit of an asteroid in a controlled manner by 2015.
. . There are key capabilities, Schweickart said, which will enable humanity to avoid devastating cosmic collisions: Early warning; a demonstrated deflection capability; and an established international decision making process.
. . Today, of the 104 currently on impact listings, "two have an elevated risk and we are watching them closely", he said. At present, the two asteroids on that "keep an eye on them roster" are 2004 VD17 and Apophis. "Extrapolating to 2018, we may have as many as 200."
May 8, 06: Meteorites that have fallen to Earth contain some of the most primitive stuff of life, a new study has found. Contrary to popular belief, they are packed with ancient carbon-rich (organic) molecules that were essential for life to get started on Earth. Until now, it was thought such matter, which was formed before our Solar System came into existence, could only be found in interstellar dust.
. . "It means that the parent bodies --the comets and "aster"oids-- of these seemingly different types of extraterrestrial material are more similar in origin than previously believed." The scientists believe that further investigation of meteorites may yield enough material to perform experiments that would not be possible with the tiny primitive organic grains from interplanetary dust particles or cometary grains returned by NASA's Stardust mission.
May 5, 06: Recent images of Titan, Saturn's largest moon, bear a striking resemblance to some of the deserts on Earth. The pictures, captured by the Cassini spacecraft as it flew by Titan last October and released today, show sand dunes at Titan's equator much like those in the Sahara desert. The dunes are up to 500 feet high and hundreds of km long --possibly made out of ice crystals, sand or some other unknown material. Dark patches on Titan, the largest of Saturn's 47 moons, were at first thought to be seas --but now they appear to be largely made up of these dunes.
. . On Earth, all wind is ultimately a result of heat differences produced by sunlight that warms the planet unevenly. Scientists have long assumed Titan is too far from the Sun to have solar-driven surface winds powerful enough to cause sand dunes. But they have more recently learned that Saturn's powerful gravity creates tidal effects in Titan's thick atmosphere. This tidal force, almost 400 times greater than that of Earth's moon tugging at our oceans, dominates near surface winds on Titan and sculpts dunes that are up to 100 meters high. These tidal winds combined with Titan's west-to-east zonal winds create dunes aligned nearly west-to-east everywhere except close to mountains, which alter wind direction.
. . Scientists also thought that the dark regions on Titan's equator were in fact seas of liquid ethane that trap sand. But the images reveal something different. The sand on Titan might have formed when liquid methane rained and eroded the ice bedrock. Although it doesn't rain frequently on Titan, when it does rain, it really pours. Energetic rain that triggers flash floods may be a mechanism for making sand, Lorenz said. The sand could also have come from organic solids produced by photochemical reactions in Titan's atmosphere.
. . "It's exciting that the radar, which is mainly to study the surface of Titan, is telling us so much about how winds on Titan work", Lorenz said. "This will be important information for when we return to Titan in the future, perhaps with a balloon."
. . Titan's flat surface is very cold, with a temperature of minus 180 degrees Celsius and scientists believe its thick atmosphere may occasionally rain methane.
May 3, 06: How long is a day on Saturn? According to a new study, it's 10 hours, 47 minutes and 6 seconds -—give or take 40 seconds. This value differs from previous estimates by up to 8 minutes and is based on measurements of a mysterious magnetic field signal emanating from the planet. If confirmed, the finding could help scientists gain a better understanding of Saturn's turbulent atmosphere and its shrouded interior.
. . [I have always taken "Saturn" to mean a ball of Hydrogen/Helium with a lil rock at the center. Here, they mean the rock.]
. . The rotation period of rocky worlds like Earth can be calculated through simple observations of the motions of a particular spot on the planet in relation to other celestial objects. This method doesn't work, however, for the likes Jupiter and Saturn because the solid cores of these gas giants are completely obscured.
. . Instead, the typically stated rotation periods for these planets are those of their magnetic fields, which scientists believe are closely tied to the rotations of their solid interiors. But measuring the rotation period of Saturn’s magnetic field is difficult because its rotational axis -—the imaginary line around which the planet rotates—- is nearly identical to the axis around which its magnetic field revolves.
. . It's like measuring the spin rate of a CD that has a distinct label on it versus a blank one that doesn't, Giampieri explained. "It's very difficult to tell if a blank CD is rotating at all." It's like relying on a substitute for a substitute: the radio signals were linked to magnetic fields that were in turn linked to the rotation of Saturn's solid core. The new method potentially cuts out one of these steps.
. . A precise value of Saturn's rotation period will help scientists accurately determine the speed of its atmospheric winds and the size of its solid core.
There are more than 150 moons in the Solar System.
Apr 29, 06: Making money on Luna is an essential part of the U.S. plan for space exploration, NASA officials said.
. . The last time humans went to Luna was aboard NASA's Apollo 17 in 1972. Since then, China has begun its own human space program and also sent representatives to this meeting.
. . Aside from the central issues of commerce, international cooperation and public engagement, the working groups also noted the need for lunar law early in the process.
. . David Beatty of NASA's Jet Propulsion Laboratory said an international legal framework would be helpful in the area of property rights, interoperability standards and making hardware from various countries work together. Such laws could govern more prosaic issues as well.
Apr 28, 06: The break-up of a comet has been shown in extraordinary detail by the orbiting Hubble Space Telescope. The images reveal the comet has crumbled into over three dozen fragments. It orbits the Sun every 5.4 years. Its break-up was first spotted in 1995 when observers noticed the comet had split into four chunks. It is not yet known if it will survive its next swing around the Sun.
Apr 20, 06: The most comprehensive study ever conducted of minerals on Mars' surface reveals the planet has undergone three distinct geological eras throughout its history, with water playing a progressively lesser role in each. If life as we know it here on Earth ever existed on the red planet, it could only have survived in the planet's infancy, during the earliest era, the study concludes.
. . "Starting about 3.5 billion years ago, conditions on Mars became increasingly dry and acidic --not a pleasant place for any form of life, even a microbe", said study team member John Mustard, a geologist from Brown University.
. . The team divided Mars' geological history into three distinct eras:
. . The first era, which lasted from about 4.6 billion years ago to 4 billion years ago, was a relatively wet one. The oldest rock --exposed by erosion, impact or faulting-- showed the presence of clay minerals, such as chamosite and nontronite, that require abundant water, moderate temperatures and low acidity to form.
. . The 2nd era was drastically different. Massive volcanic eruptions spewed sulfur into the atmosphere, turning the planet's moist and alkaline environment to a dry, acidic one. This period lasted form about 4 and 3.5 billion years and is evidenced by minerals such as gypsum and grey hematite, which were found in Meridiani and in Valles Marineris.
. . Minerals from the most recent era, which began about 3.5 billion years ago and continues to the present, show no evidence of forming with, or being altered by, liquid water. These iron-rich minerals, mostly ferric oxides, were found across most of the planet and reflect the cold, dry conditions that persist on Mars to this day.
. . The new study also revealed what is responsible for Mar's reddish hue: most likely, the researchers say, the red planet gets its color from tiny grains of red hematite or possibly maghemite, two minerals that are riddled with iron.
. . If Martian life ever did exist, it could probably have only survived during the first era, the team reports. And evidence for that life is most likely to be found in the Syrtis Major volcanic plateau, in Nili Fossae and in the Marwth Vallis Regions, two regions rich in the clay minerals abundant during Mars' youth. The researchers added that these areas would make compelling targets for future lander missions.
Apr 19, 06: If you're a science fiction reader, you know that spaceships are using antimatter to travel through space. Now NASA is working on such a spaceship to go to Mars in 45 days using only 10 milligrams of anti-electrons — or positrons — for the round trip mission. These positrons will emit gamma rays with about 400 times less energy than the ones emitted by antiprotons used in previous designs. Such a rocket would be much safer because it would reduce the time to travel to Mars and because there should be no leftover radiation after the fuel is used. There are still some remaining issues, such as the cost —-$250 million for 10 milligrams-— and the storage of antimatter which would have to be contained with electric and magnetic fields.
. . Why hasn't been tried before? Some antimatter reactions produce blasts of high energy gamma rays. Gamma rays are like X-rays on steroids. They penetrate matter and break apart molecules in cells, so they are not healthy to be around. High-energy gamma rays can also make the engines radioactive by fragmenting atoms of the engine material.
. . The NASA Institute for Advanced Concepts (NIAC) is funding a team of researchers working on a new design for an antimatter-powered spaceship that avoids this nasty side effect by producing gamma rays with much lower energy.
. . When antimatter meets matter, both annihilate in a flash of energy. This complete conversion to energy is what makes antimatter so powerful. Even the nuclear reactions that power atomic bombs come in a distant second, with only about 3% of their mass converted to energy. Previous antimatter-powered spaceship designs employed antiprotons, which produce high-energy gamma rays when they annihilate. The new design will use positrons.
. . Such an engine would be safer for the astronauts and for the environment for several reasons: it would reduce the travel time to Mars, increasing safety for the crew by reducing their exposure to cosmic rays; the reactor would not be radioactive after its fuel is used; and there should be no risk for the public even if the reactor exploded during its launch because "gamma rays would be gone in an instant."
. . This cost might seem high, but it has to be considered against the extra cost to launch a heavier chemical rocket (current launch costs are about $10,000 per pound) or the cost to fuel and make safe a nuclear reactor. "Based on the experience with nuclear technology, it seems reasonable to expect positron production cost to go down with more research.
. . Another challenge is storing enough positrons in a small space. Because they annihilate normal matter, you can't just stuff them in a bottle. Instead, they have to be contained with electric and magnetic fields.
Apr 17, 06: New dating of lunar rocks add to a growing body of evidence that the Moon and Earth were pelted by a flurry of large meteorites during a relatively brief geologic time span about 3.9 billion years ago.
. . Known as the "Late Heavy Bombardment", or LHB, this period of heightened meteorite activity would have had important implications for life on Earth, since it coincides roughly with the time that scientists think the first primitive bacteria appeared on our planet.
. . Any meteorite activity that affected the Moon probably affected Earth as well, scientists say. But terrestrial evidence for the LHB is scarce. "Unfortunately, we haven't found many very old rocks on Earth because our planet's surface is constantly renewed by plate tectonics, coupled with erosion."
. . In 2002, however, researchers discovered in sedimentary rocks a version of the element tungsten in amounts not normally found on Earth. The tungsten is believed to be of extraterrestrial origin and was estimated to about 3.7 billion years old or older.
. . If the pockmarked surface of the Moon is any indication, early Earth was pelted by a fairly steady stream of meteorites --some as big as 10km or more across-- for about 100 million years. Any life that was present or developing on Earth at the time would have been in constant peril of being blasted out of existence. It's possible that life emerged only after the bombardments slackened, or if it began earlier, it might have been disrupted or even reset by the intense hail of meteorites.
. . The cause of the LHB remains shrouded in mystery, but scientists have come up with creative explanations for what the triggering event might have been. "We may have had a 10th and 11th planet that collided", Duncan said. "It's also possible that the outward migration of Neptune scattered comets and small planet bodies, inducing collisions in the asteroid belt. The close passing of a neighboring star could have had a similar effect."
. . Other scientists have speculated that the disruptive hijinks of a fifth terrestrial world called "Planet V" was responsible. This hypothetical planet is speculated to have formed alongside Mercury, Venus, Earth and Mars but then swallowed up long ago by the Sun.
. . Before it was destroyed, however, Planet V might have perturbed the inner asteroid belt between Mars and Jupiter because of its highly eccentric orbit. This could have caused a spike in the number of objects crossing the path of Earth and Luna, the theory goes.
Apr 12, 06: Russia's leading space company laid out an ambitious plan to send manned missions to the moon by 2015, build a permanent base to tap its energy resources and dispatch a crew to Mars between 2020 and 2030.
. . The vision presented by Nikolai Sevastyanov, the head of state-controlled RKK Energiya, relies on attracting private investment. But the company's lack of government support calls its feasibility into question. Despite the recent fund increases, Russia's space budget stood at around $660 million last year compared with NASA's budget of $16.5 billion.
Apr 11, 06: An object called the 10th planet by some astronomers is not as big as previously thought. The round world, officially catalogued as 2003 UB313, & nicknamed "Xena", is about 2,390 km wide with an uncertainty of 90 km, according to new observations by the Hubble Space Telescope. Pluto is roughly 2,300 km wide, so Xena is still bigger. It showed up as just 1.5 pixels in Hubble's view. But that's enough to precisely make a size measurement, astronomers said.
. . The new size estimate suggests the object is brighter than had been thought. An object's brightness hints at its surface composition. In this case, a layer of methane frost might cover the world, astronomers speculated.
. . Astronomers have been wrangling for months over how to define the word "planet". It is not known if or when the International Astronomical Union, which rules on such things, will issue a decision. Members of an advisory board weighing the issue can't even agree on the parameters of a definition.
Apr 11, 06: The space shuttle Columbia ushered in NASA's shuttle era on April 12, 1981. A quarter century later, NASA's aging shuttle fleet is destined for retirement in 2010 as the space agency returns to a capsule-based spaceflight with its $104-billion Crew Exploration Vehicle (CEV) plan. The agency's new spaceship to is expected to debut no later than 2014 to serve the International Space Station (ISS), and push towards the Moon and possibly on the Mars. "With this [new] vehicle, we'll be able to put in an escape system that we weren't able to do with shuttle."
. . The CEV is expected to boast escape rockets capable of wrenching the crew capsule away from its booster during launch. Its broad, stubby heat shield concept is reminiscent of NASA's Mercury, Gemini and Apollo programs. The agency plans to draw on its shuttle solid rocket boosters and external tanks to construct separate CEV crew and cargo launchers.
. . "The landscape right now is littered with would-be shuttle replacement programs", Launius said, referring to past NASA projects like the National Aerospace Plane, the Orbital Space Plane, the X-34 and others.
Apr 11, 06: Venus' hellish atmosphere made up mainly of carbon monoxide and clouds of sulphuric acid where temperatures average 842 degrees F. Clouds are 18 km thick and buffeted by extremes of temperature and pressure. Its dense atmosphere creates a supercharged greenhouse effect, spinning round the planet in four days in a "super rotation" phenomenon that scientists cannot yet explain. Atmospheric pressure is 90 times greater than on Earth and no space probe that has gone into the planet's atmosphere has survived for long, with a Russian device setting the record of 110 minutes before melting in the heat.
. . Scientists are hoping that Venus Express, a virtual twin of the Mars Express craft which has been providing spectacular images of the Red Planet since 2003, will be the stepping stone to further European space missions. It will orbit the planet's poles well above the cloud cover from a distance of 250 to 66,000 km.
. . One Venus day is 243 Earth days, due to its slower rotation.
Dictionary: Pareidolia: Spotting things that don't exist —eg on Mars or in clouds. A study last year found that humans are particularly susceptible to seeing human faces where there are none, because our knowledge of the human face is so ingrained in our brains.
. . Apr 11, 06: Well-known and oddly familiar shapes in space include the equine profile of the Horsehead Nebula, located in the Orion Constellation, curvy MyCn18, better known as the "Hourglass Nebula", and the intricate remains of a star explosion seen from Earth in 1054 A.D. and now called the Crab Nebula.
. . Astronomers have sighted nebulas that look like translucent bugs, such as the Butterfly Nebula, the Ant Nebula and the Tarantula Nebula. The Cone Nebula could be seen as a giant tubeworm filter-feeding on stars and nebula NGC 2392 is a dead ringer for a chilled Eskimo hooded in a fur-lined parka.
. . Telescopes equipped with sharp eyes and X-ray vision have picked out twisted clouds of interstellar gas that have been dubbed space tornados, coiled cosmic slinkys and galaxies eerily reminiscent of the burning Eye of Sauron from Tolkien's Lord of the Rings.
. . There is also Messier 104, a galaxy that could be mistaken for a Mexican sombrero when viewed edge-on. And two galaxies passing each other in the direction of the constellation Canis Major haunt humanity with the tawny eyes of an owl. The Hubble Space Telescope has captured images of grouped galaxies that look like seashells strewn atop black sand.
. . Last week, NASA released new images of NGC 246, whose ominous look has earned it the nickname "Skull Nebula." The image shows what the outer atmosphere of a dying star can do as it travels swiftly through a thick cloud of interstellar gas.
Apr 10, 06: NASA plans a series of robotic precursor missions including the Lunar Crater Observation and Sensing Satellite, or LCROSS, which will plow into the crater, and the mapper, called the Lunar Reconnaissance Orbiter, to be built by Northrop Grumman Corp.. It's set to be launched in 2008 aboard a rocket also carrying a sophisticated lunar mapper..
. . When LCROSS strikes the crater, it is expected to create a hole 16 feet deep and send up a 998,000-kg plume of debris for sensors and cameras stationed on a second spacecraft to monitor. Dozens of ground-based telescopes, as well as possibly space observatories, such as the Hubble telescope, will be trained on the plume as well.
. . A monitoring satellite that is part of LCROSS, but separate from the reconnaissance orbiter, will then fly through the plume to collect and relay data back to Earth. It will have just 15 minutes before it too crashes into the moon, sending up a second, smaller plume for additional studies.
. . Water ice could be used to make oxygen for astronauts to breathe, as well as an oxidizer for rocket fuel.
Apr 10, 06: The Mars rover Spirit, hampered by a broken wheel, has failed to reach its destination and will spend the Martian winter at an alternate site. Spirit was rolling toward the north-facing side of McCool Hill last month to recharge on some sunshine during the winter when its right front wheel stopped working. The wheel previously had an episode of balkiness, but the latest problem is worse because the motor that spins the wheel stopped working.
. . After they failed three times to get it to climb McCool, engineers steered Spirit to a closer slope known as Low Ridge. Although the alternate site should provide enough sunlight for Spirit, it won't be as strong as it would have received on McCool Hill.
. . Opportunity is making its way to the giant Victoria crater.
Apr 10, 06: Saturn's tiny moon Enceladus may be the best place to look for life elsewhere in the Solar System. That is the view of a senior scientist working on the Cassini spacecraft, which has been studying Saturn and its moons for nearly two years. Dr Bob Brown told a major conference in Vienna, Austria, Enceladus contains simple organic molecules, water and heat, the ingredients for life. He raised the possibility of future missions to probe inside the moon.
. . Other research presented at the European Geosciences Union (EGU) annual meeting suggests that Enceladus may have a core of molten rock reaching temperatures of above 1,100C.
. . Gases are being forced through the surface, as they emerge in jets which shoot upwards for hundreds of kilometers before dispersing, eventually forming Saturn's E-ring. Most of the gas is water vapor, suggesting strongly that liquid water lies under the moon's icy surface. "But when we started looking at our spectra, we saw absorption bands from a compound that had to have carbon and hydrogen bonded together.
. . Enceladus in a very real sense becomes a stronger candidate for life than [Jupiter's moon] Europa. Bob Brown, University of Arizona, Tucson: "And when we mapped the location, it was right in these 'tiger stripes' --right where the jets are coming out, and right where it's hot-- and it's pretty hard to imagine it's getting there from anywhere but inside."
. . The organic molecules appear to be quite simple, he said, probably largely methane. The jets also contain nitrogen; and putting all this together means, said Dr Brown, that Enceladus contains all the ingredients necessary for the development of life, or of precursors to it.
. . One of the puzzling facets of Enceladus is how and why it is hot enough that it can generate liquid water and spew vapor into space. Most of its surface has a temperature of about 80 Kelvin (minus 193C). But in the "tiger stripes" it soars to 140 Kelvin (minus 123C), and the interior must be considerably hotter.
. . Computer models have been produced which try to explain just how hot the interior needs to be, and examine the processes which could produce and maintain the temperatures observed today. One model envisages energy coming from two sources, radioactive decay and tidal heating. If the magma were to cool, he said, it would become more viscous, increasing friction from tidal churning and so producing more heat. But if temperatures veered higher, the magma would flow more easily, and tidal heat production would reduce accordingly.
. . The way to answer some is a further flyby in about two years' time, shortly before the end of Cassini's scheduled mission, which could take the $3.2bn craft just 25km above the tiger stripes and through their jets. "There's a little bit of a danger, because observations suggest that the particles get larger as you get in closer", said Dr Brown. "If they're only 20 or 30 microns [in diameter] they won't hurt the spacecraft; but if they're a millimeter or two, and hit the spacecraft in the wrong place, we're dead."
. . For Europa, landers have been proposed which would burrow down through the top layer of ice into liquid water below, perhaps using heat from radioactive decay to penetrate the surface. The same approach could potentially work on Enceladus; but Bob Brown believes there may be another, simpler way in. "You could target the cracks; they clearly give you a way to get down inside, into the reservoir."
Apr 10, 06: From space, Earth looks blue and green. But put your nose to the ground, and you'll probably see just brown. Where does the brown ground come from? Green plants, a new study reveals. As plants wilt and die, their leaves and limbs drop off, bringing carbon that they've stored for a living to the soil.
. . Tiny microbes in the earth rip the dead plants apart with specialized enzymes, which break the chemical bonds in the plant material, cutting meals into the perfect size for microbes. The hungry microbes process a large amount of the carbon in the soil, even incorporating some of the element into their own cells.
. . As busy as they are, microbes can't get all the work done. "They're not quite 100% efficient", said Steven Allison, an ecologist at the University of California, Irvine. "There's carbon that doesn't get eaten by a microbe and there's carbon in their biomass. Then they die. That carbon then goes into the soil. It's a cycle, there's always carbon left over. This small bit of inefficiency accumulates over time."
. . The microbes' abundant leftovers, called humic materials, have piled up over thousands of years. The hoard of microbes' carbon scraps gives earth its dirty brown color. Carbon absorbs most colors in sunlight's spectrum, reflecting back only brown light.
Apr 8, 06: NASA's New Horizons probe has left the inner planets of the Solar System behind as it streaks toward a rendezvous with Pluto and its moons. The spacecraft, billed as NASA's fastest-flying probe, hurtled past the orbit of Mars --though not the planet itself-- Friday on its way towards a Jupiter flyby and its more distant target Pluto... at a rate of about 21 km per second. Closest approach to Jupiter: Feb. 28, 2007.
Apr 7, 06: The newly discovered outer ring of Uranus is bright blue, for the same reason the Earth's sky is blue --it is made up of tiny particles. Like Saturn's ring, the Uranus ring also has a small moon in it, called Mab. But Mab is too small and too cold to be spewing a geyser of ice.
. . "The outer ring of Saturn is blue and has Enceladus right smack at its brightest spot, and Uranus is strikingly similar, with its blue ring right on top of Mab's orbit." The scientists believe that meteoroids hitting Mab's surface throw up debris. The larger pieces remain in the moon's orbit and eventually are swept up, but smaller ones drift around more and eventually make up the ring. "In 2007, the rings will be 100 times brighter."
. . Now they are looking for rings around other planets, including Mars. Saturn's prominent "A" ring contains more debris than once thought. The Cassini-Huygens spacecraft now orbiting the planet has sent back ultraviolet images that show the ring is 35 times thicker than originally thought. A team at the University of Colorado at Boulder said the particles making up the ring range in size from dust grains to chunks as big as buses, and orbit in long stringy clumps.
Apr 6, 06: Two outer rings, one red the other blue, have been observed around the distant planet Uranus. While Uranus had been known to have inner rings of neutral color, the newly discovered outer rings show color contrasts that researchers think are caused by light reflected off particles that differ in size from one ring to the other.
. . And the outermost ring is only the second blue ring to have been observed. Also blue is Saturn's outermost ring, the researchers said. And they noted that both of the known blue rings have a moon embedded within them, while the red rings do not.
. . They speculated that the moons swept up larger pieces of debris, leaving only dust and tiny items that reflected more blue light than the red ring which could have larger pieces of debris.
Apr 5, 06: Some 4.5 billion years ago, according to one theory, a giant "aster"oid collided with an even larger object, creating Mercury and shooting debris into space.
. . With the aid of new computer simulations, scientists have examined this apparent collision to suggest why the closest planet to the Sun is denser than anticipated and how some of the impact debris ended up on Earth and Venus.
. . Pluto and its moons are also thought to have been created by an impact, as was Earth’s Moon.
. . In Mercury’s case, the idea of a collision was spawned by the fact that the rocky world contains more metal than expected for its size. And until these simulations, "we were not sure why so little of the planet's outer layers fell back in and reattached following the impact."
. . The simulation then followed the path of the ejected particles for several million years until the bits and pieces landed on a planet, were ejected from the inner solar system, or fell into the Sun. The program showed it would take up to 4 million years for half of the particles to land back on Mercury -—if they all fell back. By that time, however, much of the debris would have been carried away by solar radiation, explaining why Mercury retained much less material in its outer layers.
. . We already know of meteorites which came from Mars, but none have yet been found which came from Mercury."
Apr 3, 06: The Nasa projectile that slammed into Comet Tempel 1 last year kicked out at least 250,000 tons of water. Swift's X-ray data shows more water was released and over a longer time scale than had previously been thought. Researchers hope the new information will help them understand better the nature and construction of comets.
. . Other observatories made relatively quick studies and then turned away, Swift continued to look at the impacted "ice mountain" on and off for more than 60 days. Its patience paid off. Swift's X-ray Telescope (XRT) saw the comet continue to release water for some 13 days after the initial event, with a peak five days on from the collision. The question is why the comet continued to eject material for so long after the initial impact.
. . X-rays provide a direct measurement of the colossal amount of water thrown out as a result of the impact --the Earth-equivalent volume of about 100 Olympic sized swimming pools.
Apr 3, 06: A top Chinese space official described China's ambitious exploration plans, including robotic Moon missions starting next year. Beyond Moon missions, including a flight to collect and return lunar samples to Earth in 2017, the Chinese space agency plans to develop a nonpolluting launch vehicle that can lift 25,000 kg into orbit by 2010. Luo said China has had 46 consecutive successful launches since 1996, including 23 satellites and six Shenzhou spacecraft, which can carry astronauts. China's Moon exploration program includes a lunar fly-by in 2007, a soft landing in 2012 and a return of lunar samples by 2017.
Apr 1, 06: In the spring of 2008, Cassini is slated for another chance to look at Enceladus, flying within some 350 km. The end of Cassini's "Prime Mission" is June 30, 2008, four years after arrival at Saturn. The opportunity exists for placing Cassini in "extended mission" mode --but that's only if financial resources allow.
. . Fueled by the spacecraft's findings to date, attention is now turning to future observational roles of the interplanetary probe. One leading candidate is a sharper focus on astrobiology --even a "diving catch" to inspect in detail the makeup of those Enceladus plumes.
. . "We would aim to fly very close over the south pole [of the moon] and through the jets and plume", Porco said, "in order to make more accurate measurements of the composition of the vapor and ice particles." Of course, how close Cassini can get to this action from Enceladus will be ultimately determined by spacecraft safety issues.
. . "It's not clear that Cassini has the means to determine if the ice crystals themselves contain microbes", Porco explained. "It may require a device with much greater compositional precision than we have, so that may have to be left for a future mission." We could do in the next few years with Cassini at Enceladus what the next orbiter of Jupiter would do at Europa."
. . Unlike Jupiter's Europa, Enceladus has no intense radiation field that can limit the available time for spacecraft operations. "It has liquid water, two-and-a-half times more heat coming out of the south polar region, per square meter, than the Earth, and simple organics", Porco concluded. "It's quite provocative, and is looking very good from the astrobiological point of view."
Mar 29, 06: The US space agency (NASA) has reversed its decision to scrap the Dawn mission to two large planetisimals. The robotic probe had been cancelled, the agency said, because of technical problems and cost overruns. But intense lobbying by scientists prompted Nasa management to reappraise the mission and then reinstate it. Nasa said its technical concerns stemmed primarily from the probe's innovative ion engine.
. . Dawn, so named because it will study objects dating from the beginning of the Solar System, is expected to visit the giant space rocks Vesta and Ceres --the largest known. They're believed to have been formed in different parts of the Solar System. They bear little resemblance to one another and are of keen interest to scientists seeking clues to the formation of the early Solar System.
Mar 29, 06: Oddly shaped gaps found in Saturn's rings hint at the existence of long sought "moonlets" and support the theory that the rings are the broken remains of an icy moon shattered long ago in a violent collision, scientists say.
. . Scientists think a comet or asteroid collided with one of Saturn's moons about 100 million years ago. Such an impact would have created debris in a range of sizes, but until now, scientists only had evidence for chunks of rock that were miles in diameter and smaller particles that were about 20 meters across or less. The medium-sized moonlets -—so named because their size would be between that of a moon and smaller particles—predicted by theory were missing.
. . But in July 2004, NASA's Cassini spacecraft was hovering directly above Saturn's ring system when it detected strange gaps resembling S-shaped propellers in the planet's bright A-ring. Scientists think the gaps were formed by chunks of rock 100 m wide as they plowed through smaller particles in the ring.
. . "The planets in our solar system, the precursors anyway, probably went through this stage", said study team member Derek Richardson from the University of Maryland. Galaxies like our own Milky Way are also swirling discs of matter that have large objects, such as stars and planets, embedded within them, so could propellers also form in galaxies? Probably not, Richardson said. "The analogy in a galactic disc would be a large star with lots of little stars getting strongly perturbed by it", he said. "You don't really see that kind of process operating in galaxies. Stars are far apart."
Mar 29, 06: For scientists who spend time thinking about how planets form, life would be simpler if gas giants like Jupiter and Saturn didn’t exist. According to the standard model of planet formation, called "core accretion", planets form over millions of years as enormous blocks of rock and ice smash together to form planetary embryos, called "protoplanets", and eventually full-fledged planets. Most scientists agree that core accretion is how terrestrial planets such as Earth and Mars were created, but the model can’t convincingly explain how gas giant planets like Jupiter and Saturn came to be.
. . One major problem is that developing gas giants through core accretion takes too long. According to the best current models, the process requires several million years—longer than the typical observed lifetime of the stellar gas disks from which planets are born.
. . The other main difficulty is the so-called "migration" problem. Protoplanets are not sitting stationary in the gas disks as they bulk up. Due to gravitational interactions with the disks, the protoplanets swirl rapidly inwards toward their central stars in what scientists call "Type 1" migration. Models predict that this death spiral can take as little as 100,000 years.
. . The researchers propose several possible solutions for why their model doesn't produce lasting planets. Perhaps around a real star, several generations of protoplanets form and only those that develop later -—as the inner regions of the gas disk begins to dissipate—- survive into planetary adulthood.
. . But in one sense, this would make it harder to form gas giants, since relatively little gas would be left in the disk to form a thick atmosphere. However, it might still be possible if the planet could draw upon material sweeping in from outside its orbit, the researchers write.
. . Another solution might be that large parts of the gas disk are turbulent, and not smooth as the computer model assumed. The turbulence could be the result of magnetic field instabilities in the disk and would impede inward migration.
. . Boss is the main proponent of a controversial and relatively new theory of planet formation called "disk instability." Unlike the core accretion model, in which giant gas planets are created by first forming rocky cores and then hoarding gas to form an atmosphere, disk instability says that large planets form from large, loosely packed clumps of dust and gas whose central regions coalesce over time into cores that then grow relatively quickly.
. . Type 1 migration isn’t a problem for the disk instability model because Jupiter-sized clumps can form in as little as 1,000 years. Scientists think that once a protoplanet reaches about 10 Earth-masses, it has enough gravitational heft to carve a path for itself through the gas disk and avoid getting sucked into the star.
. . Boss thinks that core accretion and disk instability models are not mutually exclusive. It could be that core accretion works better under certain circumstances, and disk instability in others. Some scientists have even tried to combine the two into a hybrid theory.
Mar 24, 06: "Mars is 700 billion billion tons of iron and rock, wrapped in an unfamiliar landscape of canyons, craters and calderas. Nonetheless, the most compelling thing we could find on this enormous, orange orb would be a microgram of wet chemistry able to reproduce, move, grow, and evolve."
Mar 24, 06: A study of a meteorite that fell in Egypt nearly 95 years ago may offer clues as to the search for possible life on Mars. Researchers studying the meteorite that originated from Mars, found a series of microscopic tunnels within the object that mimic the size, shape and distribution to tracks left on Earth rocks by the feeding frenzy of bacteria.
. . The discovery of the tiny burrows adds intrigue to the search for life beyond Earth. However, no DNA could be extracted from the meteorite, so it's not known if the tunnels are of biological origin. The scientists said the lack of DNA also does not derail the prospect.
. . Scientists have dated the igneous rock fragment from Nakhla at 1.3 billion years in age. They believe that the rock was exposed to water about 600 million years ago, based on the age of clay found inside the rocks.
. . "Virtually all of the tunnel marks on Earth rocks that we have examined were the result of bacterial invasion", Fisk explained. "In every instance, we've been able to extract DNA from these Earth rocks, but we have not yet been able to do that with the Martian samples."
. . That being the case, there are two likely scenarios. "One is that there is an abiotic [non-living] way to create those tunnels in rock on Earth, and we just haven't found it yet", Fisk said. "The second possibility is that the tunnels on Martian rocks are indeed biological in nature, but the conditions are such on Mars that the DNA was not preserved. They may have died 600 million years ago. That may explain why we can't find DNA—it is an organic compound that can break down."
. . The SNC meteorites contain gas trapped in their interiors. The composition of this gas has been found to be nearly identical to that of the atmosphere on the red planet.
Mar 24, 06: Icy comets embedded the in belt of "asteroids" between Mars and Jupiter may point to the origin of Earth’s own water supply, scientists said today. Three comets exhibiting quite uncomet-like behavior have been found orbiting the Sun in a manner more expected of rocky asteroids. Dubbed “main-belt comets” by researchers, the objects suggests that comets and asteroids share more in common than previously thought, and that water found on Earth may have also taken root in the asteroid belt.
. . "It’s just the tip of the iceberg", said University of Hawaii astronomer David Jewitt in a telephone interview. “We said in our study [that] there may be hundreds of them out there, but there could be thousands.”
. . An object dubbed Asteroid 118401 was not really an asteroid at all. Their observations found the “asteroid” was ejecting dust like a comet. The Nov. 26 discovery came one month after a similar object was discovered by the Spacewatch project in Arizona. Astronomers have known of a third comet-like object, 133P/Elst-Pizarro, for about 10 years; it no longer seems an isolated oddball.
. . Since main-belt comets are somewhat predictable in their orbits and relatively close to Earth, they might even prove attractive targets for future missions.
Mar 20, 06: Researchers at MIT have developed a tiny light detector that could one day boost interplanetary communications to broadband speeds.The work could permit the transmission of color video between astronauts and satellites and scientists on Earth across interplanetary distances, something that is not practical with current technologies. The new light detector improves detection efficiency to 57%. Currently, light detectors only absorb about 20% of the light they receive.
. . Currently, many spacecrafts still use radio signals to send data back to Earth. Two-way laser communication in space would enable data transmission rates that are 10 to 1,000 times higher, scientists predict. Because of the large distances involved, current optical systems require large lasers and a lot of power to beam data at high rates between planets. This is usually not possible on power-starved satellites and spacecrafts. The new detector would get around these requirements because it can receive weaker signals from smaller lasers that do not use much power. The new detector is so sensitive it can detect single photons from light or laser signals in the infrared part of the optical spectrum.
Mar 20, 06: Don Davis --w the Space Society: "Just as the Human Genome Project is mapping out the intricate details of our genetic code, there will need to be the equivalent of a Gaia Genome Project to take inventory of the varied ecosystems across Earth, mapping out the interaction between the environment and its inhabitants. It may be that certain soil bacteria, insects, and plants are critically important in as yet unknown ways. When these subtle complexities are better understood, we can more intelligently design and build closed-cycle ecosystems in space.
. . Unfortunately, human expansion on Earth is in the act of displacing and erasing more and more pieces of the ecosystem. Those who would compile such a massive study of the Gaia system may soon be in the position of trying to copy the pages of a document that is burning and falling apart before their eyes.
. . As long as we live in a world where limited resources must be allocated among a growing population, we are ultimately doomed. All our efforts to increase food production and extend individual longevity will end up trading a sooner catastrophe for a later one of greater scope. So far, we are succeeding in a kind of pyramid scheme with Earth's resources, but in time the pressure of human numbers will strain and drain them. When resources become scarce and populations dense, individual freedoms are unaffordable luxuries.
. . If civilization is to be allowed to spread beyond Earth, it must take place before the world's resources are forcibly redistributed or squandered and disrupted by major wars. In recent history, we have seen we have seen our ability to reach the Moon thrown away to pay for a massive military effort that only managed to delay the communist takeover of South Vietnam by 10 years.
. . We have lost precious decades of establishing a beachhead in space due to wavering priorities and economic downturns. We cannot assume conditions will always be as right as they are now for such bold ventures as space travel. Instabilities tug at the house of cards that we call civilization. We still have time to accomplish the miracles we know are possible to achieve, but we need to begin the work while we can still afford to do it."
Mar 20, 06: NASA is considering dropping the Space Shuttle Main Engine (SSME) from its heavy-lift launch vehicle plans and using the cheaper-to-manufacture RS-68 engine instead.
Mar 18, 06: NASA's Spirit Mars rover has wrapped up exploration of a baffling feature called "Home Plate" but now faces the onset of martian winter while dealing with dropping power levels and fighting a balky right front wheel. "Our current focus is to drive like hell ... and try to get [Spirit] to safe winter havens before the power situation gets really bad", said Steve Squyres. Given the upcoming winter on Mars, with the Sun dropping low in the sky, ground controllers need to park Spirit onto north facing slopes.[It's in the S hemisphere.] "We are now in a 'drive or die' situation", Squyres said. The robot's set of power-providing solar wings are dusty.
. . During its surveying of the site, Spirit came across an important feature: a possible "bomb sag" --what looks like a volcanically-produced object that was blasted into the air. It then hit the ground, deforming sets of parallel layers evident in Home Plate. "It's the only one of these that we have found."
. . Jim Rice, a Mars Exploration Rover Project science team member at Arizona State University in Tempe considers Home Plate to be a tuff ring/maar --a feature that points to hydrovolcanic explosion(s). Rising magma below the martian surface encountered ground water or possibly ground ice, resulting in an explosive volcanic eruption.
Mar 18, 06: Terrestrial rocks blown into space by asteroid impacts on Earth could have taken life to Saturn's moon Titan, scientists announced. Earth microbes in these meteorites could have seeded the organic-rich world with life, scientists believe. They think the impact on Earth that killed off the dinosaurs could have ejected enough material for some to reach far-off moons like Titan.
. . The hypothesis of panspermia holds that life on planets like Earth and Mars was seeded from space, perhaps hitching a ride on meteorites and comets.
. . To get terrestrial life-bearing rocks to escape the Earth's atmosphere and reach space, an impact by an "asteroid" or comet between 10 and 50km is required. Only a handful of recorded strikes in geological history fit the bill. One of them is the asteroid strike 65.51 million years ago, which punched a crater between 160 and 240km wide in what is today the Yucatan peninsula, Mexico.
. . Brett Gladman from the University of British Columbia (UBC) in Vancouver and colleagues calculated that about 600 million fragments from such an impact would escape from Earth into an orbit around the Sun. Some of these would have escape velocities such that they could get to Jupiter and Saturn in roughly a million years.
. . Using computer models, they plotted the behaviour of these fragments once they were in orbit. From this, they calculated the expected number that would hit certain moons of Jupiter and Saturn. The principal targets they chose, Titan and Europa, are of considerable interest to astrobiologists, the community of scientists who study the habitability of other planetary bodies. Titan is rich in organic compounds, which provide a potential energy source for primitive life forms, Europa is thought to harbour a liquid water ocean under its thick crust of ice.
. . They calculated that up to 20 terrestrial rocks from a large impact on Earth would reach Titan. These would strike Titan's upper atmosphere at 10-15 km/s. At this velocity, the cruise down to the surface might be comfortable enough for microbes to survive the journey.
. . The news was more bleak for Europa. By contrast with the handful that hit Titan, about 100 terrestrial meteoroids hit the icy moon. But Jupiter's gravity boosts their speed such that they strike Europa's surface at an average 25 km/s, with some hitting at 40 km/s. Dr Gladman said other scientists had investigated the survival of amino acids hitting a planetary surface at this speed and they were "not good".
Mar 18, 06: Evidence for what may be a large and relatively recent impact crater has been found off the coast of Antarctica. Scientists say the evidence, if correct, points to a space rock some 5km across having crashed into the Ross Sea about three million years ago. It's a 100km-wide depression, known as Bowers Crater, under the Ross Sea. This could have generated a huge tsunami, according to a member of the team investigating the collision.
. . Team members examined cores drilled from around the area to look for evidence of an impact. In the cores, they found microscopic glassy grains shaped like teardrops, spheres and dumbbells which are collectively known as tektites. These are created when rock fragments are hurled high up into the atmosphere by the impact of a large meteoroid or "asteroid". Other glasses were also found. These are thought to have been formed by cooling of the melted rock and sediment. Similar glasses can be formed through volcanism, but the Ross Sea specimens seem to have a distinct structure under the microscope.
. . The findings alone do not prove there was an impact in the area a few million years ago, but team member Dallas Abbott says she hopes to search the core material further for a mineral called shocked quartz. The presence of this mineral is considered most diagnostic of a space collision.
Mar 18, 06: Evidence for what may be a large and relatively recent impact crater has been found off the coast of Antarctica. Scientists say the evidence, if correct, points to a space rock some 5km across having crashed into the Ross Sea about three million years ago. It's a 100km-wide depression, known as Bowers Crater, under the Ross Sea. This could have generated a huge tsunami, according to a member of the team investigating the collision.
. . Team members examined cores drilled from around the area to look for evidence of an impact. In the cores, they found microscopic glassy grains shaped like teardrops, spheres and dumbbells which are collectively known as tektites. These are created when rock fragments are hurled high up into the atmosphere by the impact of a large meteoroid or "asteroid". Other glasses were also found. These are thought to have been formed by cooling of the melted rock and sediment. Similar glasses can be formed through volcanism, but the Ross Sea specimens seem to have a distinct structure under the microscope.
. . The findings alone do not prove there was an impact in the area a few million years ago, but team member Dallas Abbott says she hopes to search the core material further for a mineral called shocked quartz. The presence of this mineral is considered most diagnostic of a space collision.
Mar 17, 06: The Deep Impact mission is casting new light on how comets formed and how they shed their ice in space. The US space agency probe sent a 370kg projectile crashing into Comet Tempel 1 and then studied the plume of debris with its suite of instruments.
. . Nasa's mission scientists say images from last July's encounter reveal as many as seven different layers on the comet's surface. Team member Mike Belton told the meeting he thought the layering was a sign of how comets like Tempel 1 were built up from lesser objects.
. . In the outer part of the early Solar System, smaller bodies called cometesimals collided and merged, gradually piling up to form the larger objects we know as comets. Similar collisions in the inner Solar System led to a loose accumulation of fragments that largely retained their internal structure. But primordial material in the outer regions was travelling at relatively lower speeds and contained less solid material. As the cometesimals hit the surface of a growing comet nucleus, they "flowed" on to the surface, researchers believe.
. . When comets are heated by the Sun, ice sublimes and is lost to space in a process known as outgassing. Some scientists have proposed that this material is coming from deep below the surface crust of the comet. But temperature data from Tempel 1's nucleus suggests the material must be lost from only a few centimeters below the surface.
Mar 17, 06: Accepted views of how the planet Venus evolved are challenged by new age dates for its surface. Massive volcanism 500 million years ago was thought to have covered over much of the planet's ancient features. But work carried out at Imperial College London, UK, suggests a "volcanic catastrophe" is not needed to explain the look of Venus's surface. Scientists will have an early opportunity to examine the new ideas --Europe's Venus Express spacecraft is due to arrive at the planet next month for a two-year investigation.
. . Researchers date planetary surfaces by looking at the distribution of their impact craters. On most planets and moons, impact craters tend to be clustered on very old parts of the surface, due to the heavy bombardment that is believed to have taken place in the early Solar System. But craters on Venus are distributed randomly over the whole planet. This has led some scientists to the conclusion that most of the surface is of similar age.
. . Using computer modelling, they came up with a suite of possible scenarios that were compatible with the planet's cratering record and surface features. They concluded that there was no need to invoke massive outpourings of lava over a short period. Instead, the planet's present-day surface could be compatible with a slow decline of volcanic activity, they argue, over as long as two billion years. "We haven't shown that a very short event isn't possible, we've just shown that there are a much wider range of possibilities. A very short event is, a priori, quite unlikely, given that there is a much wider range of likely realities."
. . Dr Ghail believes the surface features of Venus do not necessarily reflect the rate of plate tectonics on the planet. Instead, he thinks high temperatures in the interior create a weak zone between the crust and the mantle which essentially decouples, or separates, them from each other. This would allow more continual plate tectonic activity that would leave little evidence on the surface.
Mar 17, 06: The formation of odd spokes in Saturn's rings may depend on the amount of sunlight striking the planet's ring plane, scientists said. A new study suggests that the spokes appear more often while Saturn's rings are edge-on to the Sun, but fade out when the rings are completed tilted out at maximum exposure. "In fact, they can be entirely switched off at times."
. . The spokes in Saturn's rings intrigue astronomers, who believe the phenomenon may aid investigations into the planet's magnetic field. They can reach 9,650 km in length and span 2,400 km in width, but their role and formation within the ring plane are not completely understood.
Mar 17, 06: NASA is taking another look at the decision to cancel the Dawn mission that would explore two large asteroids in the solar system.
Mar 17, 06: To scientists scanning the cosmos for signs of life, the stunning discovery of what appears to be water on an obscure moon orbiting Saturn couldn't come at a more pivotal time. With a fresh focus on returning astronauts to Luna, NASA has squashed several missions that over the next decade were to have continued the search for extraterrestrial life.
. . Can images from Enceladus, an icy moon located more than 800 million miles from Earth, supercharge interest and funding for life-finding missions? Probably not any time soon. Missions take years to launch and what enthusiasm NASA has for finding otherworldly life already is focused on Mars and the Jupiter moon Europa.
Mar 12, 06: NASA scientists have a new mystery to solve: How did materials formed by fire end up on the outermost reaches of the solar system, where temperatures are the coldest?
. . The materials were contained in dust samples captured when the robotic Stardust spacecraft flew past the comet Wild 2 in 2004. A 45-kg capsule tied to a parachute returned the samples to Earth in January. The samples include minerals such as anorthite, which is made up of calcium, sodium, aluminum and silicate; and diopside, made of calcium magnesium and silicate. Such minerals only form in very high temperatures. "That's a big surprise. People thought comets would just be cold stuff that formed out ... where things are very cold."
. . It is also possible that the comet particles could have been formed in another solar system and catapulted into the Solar System. To determine where the particles originated, scientists are now studying their isotopic makeup. About 150 scientists worldwide have been studying the dust since it arrived.
. . Don Brownlee, a University of Washington astronomer who is the mission's principal scientist, said in a few weeks or months, he and his colleagues hope to know more. "It depends on whether the isotopic composition indicates these grains are from the Solar System or from another star."
Mar 10, 06: The color of Pluto's two recently discovered satellites are essentially the same neutral color as Pluto's large moon, Charon, scientists said. Charon's surface is known to consist primarily of water ice, so the similar colors of P1 and P2 suggests that these moons have water ice surfaces, too.
. . The finding supports the hypothesis that all three of Pluto's moons were formed from a single giant impact that took place about 4.6 billion years ago. Recent observations about the orbital motions of Pluto's recently discovered moons, P1 and P2, also support this theory.
. . Pluto's surface, in contrast, has a reddish hue, which is believed to be the result of interactions between sunlight and nitrogen and methane surface ices.
NASA essentially developed astrobiology as a whole new interdisciplinary scientific field from scratch. It now has thousands of researchers, many international affiliates, multiple peer reviewed journals and is growing. Even NSF has been amazed by what NASA's astrobiology program has accomplished.
Mar 9, 06: Saturn's moon Enceladus, one of the brightest objects in the Solar System, may have pockets of liquid water lurking beneath its surface feeding great jets that spew from the satellite, hinting at the possibility of a habitable environment, researchers said.
. . Observations from the Cassini spacecraft currently studying Saturn and its myriad moons shows Enceladus to be a geologist's dream, with an active plume spewing water and other material spaceward, as well as a hot spot of thermal activity at its south pole. But unlike Europa, which researchers believe harbors a vast ocean beneath kilometers of thick ice, Enceladus' water may be just below the surface.
. . The moon is only the third other body in the Solar System --Earth, Jupiter's moon Io and possibly Neptune's moon Triton are the others-- known to have active volcanic processes.
. . But the spacecraft, Kargel wrote, will not be able to determine whether subsurface water pockets could offer a habitat suitable for living organisms. "Any life that existed could not be luxuriant and would have to deal with low temperatures, feeble metabolic energy, and perhaps a severe chemical environment", Kargel wrote. "Nevertheless, we cannot discount the possibility that Enceladus may be life's distant outpost."
. . The plume may have been erupting continuously for 15 years, appears to replenish Saturn's E-ring with material and provide the source of oxygen and hydrogen permeating the planet's neighborhood. The plume's activity appears tied to the thermal hotspot at Enceladus' south pole, the source of that internal heat remains undetermined.
Mar 9, 06: NASA canceled a mission to visit two asteroids, five months after the program was put on hold because of cost overruns and technical problems. The Dawn spacecraft was set to explore the solar system's largest asteroids, Ceres and Vesta. Dawn would have been the first spacecraft to orbit the two asteroids, which scientists believe formed in different parts of the solar system and had different evolutionary processes.
Mar 9, 06: Scientists generally agree several ingredients are needed for life to emerge, including water in liquid form and a stable heat source.
. . Enceladus (en-sel'-e-des) is the shiniest object in the Solar system. It was long thought to be cold and still, in part because it receives so little sunlight. But scientists now believe it is a geologically active moon that possesses an unusually warm south pole and a significant atmosphere. The south pole "hot spot" is still frigid by Earth standards. The temperature there is minus-297 degrees F — about 20 degrees warmer than the neighboring region.
. . The water is believed to come from underground reservoirs that are under high pressure. Porco said the venting has probably been going on for at least several thousand years, perhaps indicating a lasting heat source underground. Cassini found the geysers are mostly made up of water vapor and ice particles with significant amounts of carbon dioxide and trace amounts of methane —-all of which probably help to replenish the moon's atmosphere.
. . Scientists have long known that many of Saturn's moons have water. They took an especially close look at Enceladus because it seemed to have a smooth surface --suggesting recent geological activity that, in turn, could mean liquid water. Liquid water is a key requirement for life. Several moons have been found to have evidence of liquid water and the chemical elements needed to make life, including Europa. But scientists are far more intrigued by the plume itself, a gigantic geyser of water vapor and tiny ice particles. The plume is half the size of the moon. The findings help confirm theories that Enceladus was the source of Saturn's outer E-ring, the researchers said.
. . Saturn has at least 47 moons. Enceladus is seventh in distance from the planet. It's 500 km in diameter, orbits Saturn at a mean distance of 238,020 km, and has equal orbital and rotational periods of 1.37 earth days.
. . Mean diameter 505 km (512×494×489 km) [3]
. . Mass: 1.08×1020 kg 1
. . Mean density: 1.61 g/cm3
. . Surface gravity: 0.113 m/s2 ( < .1 G)
. . Escape velocity: 0.241 km/s (866 km/h)
. . Surface temperature: mean: 51 K; max: 80 K
Mar 7, 06: The Great Red Spot that has dominated the planet Jupiter's cloudtops for hundreds of years now has a companion. The gas giant is growing another red spot, which US space agency (Nasa) astronomers have nicknamed "Red Jr". Red Jr is about half the size of the Great Red Spot and almost exactly the same color. It was first observed in 2000, when three smaller spots collided and merged.
. . At first, Oval BA remained white --the same color as the storms that combined to create it. But over the past few months, it has started to change in appearance. "The oval was white in November 2005, it slowly turned brown in December 2005, and red a few weeks ago."
. . No one is quite sure why the Great Red Spot is red. One theory is that the storm dredges material from deep beneath Jupiter's cloudtops and lifts it to high altitudes. Here, ultraviolet rays from the Sun turn color-changing compounds (or chromophores) red.
The heads of the agencies responsible for the International Space Station say it will be finished by 2010.
Mar 8, 06: An OSU study suggests that a large object hit the far side of the moon and sent a shock wave through Luna's core and all the way to the Earth-facing side.
. . The early Apollo missions revealed that the moon isn't perfectly spherical. Its surface is warped in two spots; an earth-facing bulge on the near side is complemented by a large depression on Luna's far side. Scientists have long wondered whether these surface features were caused by Earth's gravity tugging on Luna early in its existence when its surface was still molten and malleable. But the study leaders say these features are instead remnants from ancient impacts. They came to this conclusion after mapping Luna's interior through gravity fluctuations measured by NASA's Clementine and Lunar Prospector satellites to map Luna's interior.
. . They expected to see defects beneath Luna's crust that corresponded to craters on the surface. Old impacts, they thought, would have left marks only down to the mantle, the thick rocky layer between Luna's metallic core and its thin outer crust. And that's exactly what they saw, at first. But then they noticed on the far side of Luna that the crust looks as though it was depressed and then recoiled from a giant impact. Beneath the depression, the mantle dips down as if it had absorbed a shock. Evidence of the ancient catastrophe should have ended there. But some 700 miles directly below the point of impact, a piece of the mantle still juts into Luna's core today.
. . But what they saw from the core all the way to the surface on the near side of Luna was even more surprising. The core bulges, as if core material was pushed in on the far side and pulled out into the mantle on the near side. Above that, an outward-facing bulge in the mantle, and above that --on the Earth-facing side of Luna-- sits a bulge on the surface.
. . To the Ohio State scientists, the way these features line up suggests that a large object such as an asteroid hit the far side of Luna and sent a shock wave through the core that emerged on the near side. The scientists believe that a similar, but earlier impact occurred on the near side. On the Earth-facing side of Luna, magma from Luna's mantle once flowed out onto the surface and flooded lunar craters.
Mar, 06: The ancient asteroid that slammed into the Gulf of Mexico and purportedly ended the reign of the dinosaurs occurred 300,000 years too early, according to a controversial new analysis of melted rock ejected from the impact site.
. . Markus Harting of the University of Utrecht in the Netherlands and a small group of scientists thinks the Chicxulub impact happened too early to have been the infamous dinosaur-killer. Harting analyzed BB-sized glass spherules found in multiple layers of sediments from northeast Mexico, Texas, Guatemala, Belize and Haiti—regions that are in relatively close proximity to the Chicxulub impact site.
. . Based on the spherules' chemical composition, Harting concludes they all formed from rock melted during the Chicxulub impact. The spherules were not found in a single layer of sediment, however, but were instead scattered throughout several layers. Some appeared worn and weathered, as if they had been exposed to the elements and shifted around.
. . Some of the spherules Harting found were located meters below the layer of iridium-rich clay that marks the end of the Cretaceous period 65.51 million years ago, when large dinosaur indeed disappeared from the planet (some hung on and became birds). This layer is also known as the "K-T boundary." Iridium is a chemical element commonly found in asteroids and comets and the K-T boundary has been touted as the smoking gun linking the dinosaurs' demise to an asteroid impact.
. . Harting believes his work supports the theory that the Chicxulub impact occurred roughly 300,000 years earlier than many scientists have commonly assumed. His findings will be presented at the Backbone of the Americas-Patagonia to Alaska meeting in Argentina on April 3.
. . Due to the large margins of error involved, Harting could not determine the age of the spherules directly, but instead relied on studies of sediment deposits performed by Gerta Keller at Princeton University and colleagues.
. . Keller thinks dinosaurs survived the Chicxulub impact but were finished off by a larger, more catastrophic impact that happened roughly 300,000 years later. It was this later impact, Keller says, that is responsible for the K-T boundary.
. . Because the Chicxulub impact would have been many orders of magnitude stronger than any volcano eruption, scientists have to travel hundreds or even thousands of miles from ground zero to find sediment layers not disturbed by the impact. Frank Kyte of the University of California, Los Angeles has done just that.
. . Kyte has analyzed the chemical composition of spherules collected from the K-T boundary layer in places all around the world, including deep ocean basins, where the sediment isn't as churned up as in the Gulf of Mexico. From his studies, Kyte has concluded that there is only one spherule layer, not many as Harting claims, and that this layer is located precisely at the K-T boundary. "There is all kinds of evidence that there was one big impact, and virtually no solid, strong evidence that there was more than one", he said.
Mar 2, 06: The Cassini spacecraft studying Saturn and its satellites made the first of four planned Titan flybys today in a search for subsurface oceans. The potential of a subsurface ocean, possibly beneath a sheet of methane-rich ice, factors greatly for astronomers hoping to pin down how Titan replenishes the methane in its atmosphere. Titan's methane is likely locked in ice covering an ocean of water and ammonia.
. . Methane makes up about 2% of Titan's thick, predominantly nitrogen-rich atmosphere, and is apparently replenished over time through outgassing since it is destroyed by sunlight.
. . "Finding the subsurface ocean will not give us direct evidence of the outgassing of methane", Tobie said, adding that a subsurface ocean covered in methane-rich ice is predicted by his study. "But it will help us put constraints on our model." Models developed by Tobie and his colleagues suggest Titan's methane stemmed from three primary outgassing events during the moon's 4.5-billion-year evolution.
. . The latest event occurred about 500 million years ago due convection within its ice crust, according to the study. Convection in Titan's core also prompted a methane event about two billion years ago, with the first outgassing occurring just after the moon formed, the study suggests. Methane locked within ice on Titan could be freed by a cryovolcanic (ice volcano) event, such as that suggested in a 2005 study, Tobie said.
Mar 2, 06: A new asteroid tops astronomers list of those to watch, with the odds of an impact put at about 1-in-1,000 for May 4, 2102. The odds will likely go down or evaporate in the future when further observations allow astronomers to refine their projections of the object's path. For now, however, the asteroid known as 2004 VD17 is the only one rated as a 2 on the Torino Scale, a zero-to-10 ranking of space-rock risk on which zero is little or no risk.
. . The rock is about 500 meters in diameter. Though not big enough to cause global devastation, it could cause significant regional devastation were it to hit the planet.
. . Asteroid Apophis, formerly called 2004 MN4, is ranked Torino Scale 1, with impact odds of about 1-in-5,000 on April 13, 2036.
Feb 23, 06: As scientists and engineers figure out how to return astronauts to Luna, set up habitats, and mine lunar soil to produce anything from building materials to rocket fuels, they are scratching their heads over what to do about Moon dust. This troublesome material is every-where on Luna's surface. The powdery grit gets into everything, jamming seals and abrading spacesuit fabric. It also readily picks up an electrostatic charge. This characteristic causes it to float or levitate off the lunar surface and stick to faceplates and camera lenses. The fine dust might even be toxic.
. . Larry Taylor, distinguished professor of planetary sciences at the University of Tennessee, has an idea about what to do with this troublesome dust. He suggests that it can be melted into a useful material. He once put a small pile of lunar soil brought back by Apollo astronauts into a microwave oven. Taylor found that it melted rapidly, within 30 sec, at only 250 W. . The reason it melted so quickly has to do with its composition. Lunar regolith, or soil, is produced when micrometeorites plow into lunar rocks and sand at high-impact velocities, melting and creating glass. The glass contains nanometer-scale beads of pure iron--so-called "nanophase" iron. Those tiny iron beads efficiently concentrate microwave energy, causing the beads to "sinter", or fuse the loose soils into large clumps.
. . This observation has inspired Taylor to imagine all kinds of machinery that could be sent to the Moon and then used to fuse lunar dust into useful solids. "Picture a buggy pulled behind a rover that is outfitted with a set of magnetrons", he suggests. (A magnetron is the heating element in a microwave oven.) "With the right power and microwave frequency, an astronaut could drive along, sintering the soil as he goes, making continuous brick down 0.5 m deep", Taylor points out. He adds that by changing the power settings the astronaut could melt the top inch or two of the soil to make a glass road.
. . The idea has promise. It could result in useful products such as sintered rocket landing pads, roads, bricks for habitats, and radiation shielding, while at the same time providing a means for dust abatement. "The only limit", says Taylor, "is imagination."
. . Russell Kerschmann: "The real problem is the lungs", he explains. "In some ways, lunar dust resembles the silica dust on Earth that causes silicosis, a serious disease." Formerly known as "stone-grinder's disease", silicosis first came to idespread public attention during the Great Depression when hundreds of miners drilling the Hawk's Nest Tunnel through Gauley Mountain in West Virginia died within five years of breathing the fine quartz dust kicked into the air by dry drilling --even though they had been ex-posed for only a few months. "It was one of the biggest occupational health disasters in U.S. history."
. . Quartz, the main cause of silicosis, is not chemically poisonous. "You could eat it and not get sick. But when quartz is freshly ground into dust particles smaller than 10 nm (for comparison, a human hair is 50+ nm wide) and breathed into the lungs, they can embed themselves deeply into the tiny alveolar sacs and ducts where oxygen and carbon dioxide gases are exchanged." There, the lungs cannot clear out the dust via mucus or coughing. Moreover, the immune system's white blood cells commit suicide when they try to engulf the sharp-edged particles to carry them away in the blood-stream. In the acute form of silicosis, the lungs can fill with proteins from the blood. He adds that it is as if the victim slowly suffocates from a pneumonia-like condition.
. . Lunar dust, which like quartz is a compound of silicon, is (to our current knowledge) also not poisonous. But like the quartz dust in the Hawk's Nest Tunnel, it is extremely fine and abrasive, almost like powdered glass. Astronauts on several Apollo missions found that it clung to everything and was almost impossible to remove. Once it was tracked inside the lunar module, some of the dust easily became airborne, irritating lungs and eyes.
. . Martian dust could be even worse. It is not only a mechanical irritant but also perhaps a chemical poison. Mars is red because its surface consists largely of iron oxide and oxides of other minerals. Some scientists suspect that the dusty soil on Mars may be such a strong oxidizer that it will burn any organic compound, such as plastics, rubber, or human skin, as viciously as undiluted lye or laundry bleach.
. . "If you get Martian soil on your skin, it will leave burn marks", says University of Colorado engineering professor Stein Sture, who studies granular materials such as lunar and Martian dirt for NASA. Because no soil samples have ever been returned from Mars, "we do not know for sure how strong it is, but it could be pretty vicious." Martian dust may also contain trace amounts of toxic metals, including arsenic and hexavalent chromium --a carcinogenic toxic waste.
Feb 22, 06: The two moons discovered around Pluto last year were likely formed from the same giant impact that created the planet's much larger satellite, Charon, scientists say. The idea suggests that other Kuiper Belt Objects might also harbor multiple satellites and raises the possibility that Pluto is encircled by rings fashioned from debris ejected from the surface of the tiny moons. The two moons, called P1 and P2 for now, were discovered in May 2005. Scientists now think the two moons are roughly 60 and 50 km in diameter. Charon has an estimated diameter of about 1,200 km.
. . For every twelve orbits Charon makes around Pluto, P1 makes almost two orbits and P2 completes nearly three --about 38 days for P1 and 25 days for P2. This ratio would likely not be constant if P1 and P2 were merely passing objects captured by Pluto's gravity. The most likely explanation for this arrangement, scientists figure, is that all three moons were born of the same event. The two new members of Pluto's family make it the only object in the Kuiper Belt known to have *multiple satellites.
Feb 21, 06: A special study group has advised NASA that Venus is far too hellish of a world for life to exist on or below the planet's surface. Furthermore, while the potential for life in the clouds of Venus can't be ruled out, the expert panel gauged this possibility as extremely low. The assessment concluded that "no significant risks" exist in contaminating Venus with Earth organisms on any future landers or atmospheric probes, including balloons. Likewise, any surface materials shot back from Venus or whiffs of its atmosphere returned to Earth pose no significant risk to our planet in terms of "back contamination".
. . Surface temperatures are hot enough to melt lead. The surface pressure on Venus is the crushing equivalent of being nearly a mile deep in Earth's ocean. The landscape, covered in volcanic rock, is desolate and waterless, but rich in sulfur. Venus's atmosphere is more than 96% carbon dioxide, with 3% nitrogen and traces of other gases.
. . Enshrouding Venus are three distinct cloud layers. Water vapor there ranges from a few parts per million at the top of the cloud deck to a few tens of parts per million at the base. Cloud droplets, however, are formed of extremely concentrated sulfuric acid. Now toss in for good measure a high flux of solar ultraviolet radiation that floods the cloud deck.
. . "There may well have been periods when Venus was entirely cloud free. If this has occurred, any cloud-based microbial ecology would have been permanently extinguished", the report explained. "At any rate, any life forms that had adapted to living in the extremely acidic environment of Venus's cloud layer would not be able to survive in the environmental conditions found on Earth."
. . "I wonder if they would come to the same conclusion if we would have confirmation that oceans on the surface of Venus existed for billions of years until fairly recently", Schulze-Makuch said, and that life originated there and later found a refuge in the Venusian atmosphere. Even as hostile conditions gradually increased within the atmosphere, life may have been able to hang on and could still be present in the cloud layers, he suggested. "For me this is an entirely plausible scenario."
Feb 20, 06: Scientists said they have begun slicing and dicing the first of hundreds of microscopic specks of comet dust, virtually unchanged since the birth of the solar system, that a NASA spacecraft successfully returned to Earth in late January.
. . Preliminary analysis shows the dust, captured when the robotic Stardust spacecraft flew past the comet Wild 2 in January 2004, is unmistakably cometary in origin, said Don Brownlee, a University of Washington astronomer who is the principal scientist for the $212 million mission. As such, the grains represent pristine samples of the primitive material that came together to form the sun, the nine planets and everything else in the solar system, including human beings.
. . The initial work on the samples shows they contain glassy materials, crystals like olivine and various trace elements, Brownlee said. Each tiny grain is being sliced, sometimes into hundreds of sections, for detailed analysis. Some grains are just four microns in diameter, meaning it would take 25 of them to equal the width of a human hair.
. . Stardust captured the comet samples in a material called aerogel, a silicon-based material that is 99.8% empty space. The particles left telltale tracks —-some shaped like carrots, others like turnips-— in the icecube-sized chunks of aerogel when they struck. Each particle can take hours to remove, including through the use of a computer-controlled needle that cuts around each track. While the samples appear to lack indicators of water, they do contain sulfides, a key component to life.
. . Progress is being made on designing a Crew Launch Vehicle, as well as a mega-cargo carrier that has the growth potential to toss over 300,000 pounds into low Earth orbit --more than the Saturn 5 booster utilized in the Apollo Moon program. The two launchers are both borrowing heavily from solid rocket booster and external tank work honed within the space shuttle program. The shuttle is due to be retired in 2010. Also on tap for use in the two launchers is incorporating a Saturn 5-era J-2 upper stage engine --a motor capable of being started in flight and restarted anytime.
. . The lunar dust "is a real problem"..."one of the big issues that we have to deal with", Horowitz advised. Spacesuits used on Apollo were pretty much trashed within a few days, he said, as tiny, razor-sharp dust particles jammed suit joints.
Feb 9, 06: ~Mark Sonter; National Space Society: "The Near Earth Asteroids offer both threat and promise. They present the threat of planetary impact with regional or global disaster. And they also offer the promise of resources to support humanity's long-term prosperity on Earth, and our movement into space and the solar system.
. . The technologies needed to return asteroidal resources to Earth Orbit (and thus catalyze our colonization of space) will also enable the deflection of at least some of the impact-threat objects.
. . As one startling pointer to the unexpected riches in asteroids, many stony and stony-iron meteorites contain Platinum Group Metals at grades of up to 100 ppm (or 100 grams per ton). Operating open pit platinum and gold mines in South Africa and elsewhere mine ores of grade 5 to 10 ppm, so grades of 10 to 20 times higher would be regarded as spectacular if available in quantity, on Earth.
. . About 10% of Near-Earth Asteroids are energetically more accessible (easier to get to) than the Moon (i.e. under 6 km/s from LEO), and a substantial minority of these have return-to-Earth transfer orbit injection delta-v's of only 1 to 2 km/s. Return of resources from some of these NEAs to low or high earth orbit may therefore be competitive versus earth-sourced supplies.
. . The most accessible group of NEAs for resource recovery is a subset of the Potentially Hazardous Asteroids (PHAs). These are bodies (about 770 now discovered) which approach to within 7.5 million km of earth orbit. The smaller subset of those with orbits which are earth-orbit-grazing give intermittently very low delta-v return opportunities (that is it is easy velocity wise to return to Earth). These are also the bodies which humanity should want to learn about in terms of surface properties and strength so as to plan deflection missions, in case we should ever find one on a collision course with us.
. . Professor John Lewis has pointed out (in Mining the Sky) that the resources of the solar system (the most accessible of which being those in the NEAs) can permanently support in first-world comfort some quadrillion people. In other words, the resources of the solar system are essentially infinite… And they are there for us to use, to invest consciousness into the universe, no less. It's time for humankind to come out of its shell, and begin to grow!!
. . Since the competing source of raw materials is "delivery by launch from Earth", which imposes a launch cost per kilogram presently above $10,000 per kg, this same figure represents the upper bound of what recovered asteroidal material would be presently worth in low earth orbit.
. . Future large scale economic activity in orbit is unlikely to develop however until launch cost drops to something in the range $500 to $1,000 per kilogram to LEO. At that point, any demand for material in orbit which can be satisfied at equal or lower cost by resources recovered from asteroids, will confer on these asteroidal resources an equivalent value as ore in true mining engineering terms, i.e., that which can be mined, have valuable product recovered from it, to be sold for a profit. Now, $500,000 per ton product is extraordinarily valuable, and is certainly worth chasing!
. . Note that the asteroidal materials we are talking about are, simply, water, nickel-iron metal, hydrocarbons, and silicate rock. Purified, and made available in low earth orbit, they will be worth something like $500,000 per ton, by virtue of having avoided terrestrial gravity's "launch cost levy."
. . When will we see asteroid mining start? Well, it will only become viable once the human-presence commercial in-orbit economy takes off. Only then will there be a market. And that can only happen after NASA ceases acting as a near-monopolist launch provider and thwarter of competition, and reverts to being a customer instead.
. . A developing in-space economy will build the technical capability to access NEAs, almost automatically. And regardless of the legal arguments about mineral claims in outer space, once the first resource recovery mission is successful, what's the bets on a surge in interest similar to the dotcom-boom and biotech-boom?
Feb 9, 06: The "Man in the Moon" illusion, familiar to various cultures around the world, was created by powerful asteroid impacts that rocked the satellite billions of years ago, a new study suggests. It may also help explain the origins of two mysterious bulges on Luna's surface. There is a bulge on the Earth-facing side, called the near side, and another bulge on the far side.
The new analysis reveal that shock waves from some of Luna's early asteroid impacts traveled through the lunar interior, triggering volcanic eruptions on the Moon's opposite side. Molten magma spewed out from the deep interior and flooded the lunar landscape. When the magma cooled, it created dark patches on Luna called "lunar maria" or "lunar seas." Back then, Luna was much closer to the Earth than it is today and the gravitational interactions between the two were much stronger. The researchers think that when magma spilled out of Luna's interior, Earth's gravity immediately grabbed hold and hasn't let go since.
Feb 7, 06: NASA's newly issued budget has lowered a flagship mission of exploration to half-mast. Backed by scientists and study groups, a mission to Jupiter's moon Europa is missing in action within the pages of NASA's Fiscal Year 2007 budget.
. . The smallest of Jupiter's Galilean satellites --about the size of Earth's Luna-- Europa has a facade of white and brown colored water ice. Hidden under that frozen crust, Europa may well harbor a global ocean of liquid water. And coupled to the prospect for a subsurface ocean comes the tempting thought of life. Both the National Academy of Sciences and internal NASA advisory committees have endorsed Europa exploration as the highest priority solar system objective after Mars.
. . A nuclear-powered Europa Explorer would be loaded with scientific gear. For example, the Europa orbiting spacecraft could be outfitted with ice-penetrating radar to detect shallow water, or partial melt. If the moon's icy face is thin, or thin in spots, that radar could possibly penetrate through the ice to an ocean. Also onboard would be a camera system, infrared sensor hardware, as well as equipment to discern the crunching, cracking, creaking, and overall strength of Europa's ice shell --to help validate that the moon really does have a global liquid water ocean.
. . One possible additional payload on Europa Explorer: a simple lander. Pappalardo said a lander is still being bandied about, but carrying what kind of technology and at what cost are questions awaiting answers.
Feb 2, 06: Comet Tempel 1, the target of NASA's Deep Impact space probe, has three patches of ice on its surface, but most of the frozen water probably lurks deeper inside, scientists reported. This marks the first time ice has been detected on the nucleus, or solid body, of any comet. We can therefore firmly conclude that most of the water vapor that escapes from comets is contained in ice particles found below the surface."
Feb 1, 06: Two objects lurking near Jupiter and once considered rocky asteroids have turned out to be comets made up mostly of ice and dirt. Using the Keck II Laser Telescope in Hawaii, astronomers found that the two objects, 617 Patroclus and its companion, Menoetius, had a density of only 0.8 grams per cubic centimeters --only a third that of rock.
. . The finding could mean that many or most of asteroid-like objects hovering around Jupiter and known as Trojans are actually comets that originated much farther from the Sun and which were captured by the giant gas planet when the solar system was still young.
. . Patroclus and Menoetius are the only known binary objects around Jupiter. The pair orbit around each other while floating 465 million miles (750 million kilometers) from Jupiter in one of gas planet's two so-called Lagrange points. At these points, the gravitational field of Jupiter and the Sun are perfectly balanced, and objects can be captured and brought to relative rest. Jupiter has two Lagrange points, one in front and the other behind as the planet orbits the Sun. [Well, actually, any 3-body system has 5. Google L-5 Society.]
. . Patroclus and Menoetius are estimated to be about 122 km and 112 km wide, respectively.
Feb 1, 06: Scientists say they have confirmed that a so-called 10th planet discovered last year is bigger than Pluto, but that likely won't quell the debate over what makes a planet.
. . By measuring how much heat it radiates, German scientists led by Frank Bertoldi of the University of Bonn estimated that 2003 UB313 is about 3,000 km in diameter, give or take 300 km. Pluto is 2,300 km wide. They've nicknamed the object Xena and is pressing for it to be given full planet status.
. . "It is now increasingly hard to justify calling Pluto a planet if UB313 is not also given this status." It is round and orbits Sol. But because several other objects meet those criteria and also approach Pluto's size, astronomers have been wrangling for months over how to define the word "planet." It is not known if or when the International Astronomical Union, which rules on such things, will issue a decision.
. . UB313 is much farther away. Its elongated orbit takes it far out into the icy Kuiper Belt, twice as far from the Sun as Pluto. Many astronomers now say Pluto is a Kuiper Belt Object and should never have been called a planet. So if 2003 UB313 is termed a planet, as some suggest, then a handful of other good-sized, round worlds known to exist--and perhaps hundreds yet to be found in the Kuiper Belt--would also have to be called planets. Among the other candidates: Sedna, which is about three-fourths as large as Pluto, 2004 DW, and Quaoar.
. . "You could have a distinction which says, 'everything bigger than Pluto is a planet', but then you are in danger of finding four or five of these objects in the next few years and you end up asking yourself, 'did we really mean to create 15 planets?'"
Jan 31, 06: Using a new climate predicting model, scientists can predict cloud formation on Titan 30 years into the future. That may sound like a long range forecast, but 30 Earth years correspond to just one year on Titan, Saturn's largest moon. The new computer model, however, will help scientists predict where and when large seasonal clouds will appear and disappear across the moon, enabling them to plan productive future observations.
Jan 30, 06: ATK Thiokol is preparing to begin work on a more powerful variant of the space shuttle solid-rocket motor it has long produced as part of a streamlined NASA exploration plan that would land astronauts on Luna in early 2017, a year earlier than previously envisioned.
Jan 20, 06: One of the biggest cosmic dust storms of the past 80 million years left a blanket of material on Earth after an "asteroid" in space broke apart, researchers said. The conclusion is based on evidence in ocean sediments, which computer models have tied to an observed bevy of asteroid siblings still roaming the solar system. The thinking is that the space rocks were once part of a larger asteroid, some 160 km wide, that broke up --probably in a collision-- out in the asteroid belt between Mars and Jupiter. The drama took place 8.2 million years ago. That much has been reasoned before. The event would have created vast amounts of dust, some of which would have been scooped up by our planet.
. . The scientists report a spike in helium 3, a type of helium that's rare on Earth and typically of extraterrestrial origin, in a layer of sediment dated to that time frame. The dust rich in helium 3 spiked about 8.2 million years ago and gradually decreased over the course of 1.5 million years, the data shows. "The helium 3 spike found in these sediments is the smoking gun that something quite dramatic happened to the interplanetary dust population 8.2 million years ago", said Caltech geochemist Ken Farley. "It's one of the biggest dust events of the last 80 million years."
. . Interplanetary dust is nothing new to scientists. About 20,000 tons of it lands on Earth every year. While in space, it picks up helium 3 from a wind of material flowing out from the Sun. When asteroids collide, more debris wafts through the solar system. Much of it is drawn toward the Sun, and on its way in some is captured by Earth. "While asteroids are constantly crashing into one another in the main belt", said study member William Bottke of the Southwest Research Institute, "only once in a great while does an extremely large one shatter."
Jan 20, 06: More than 9,000 pieces of space debris are orbiting the Earth, a hazard that can only be expected to get worse in the next few years. And currently there's no workable and economic way to clean up the mess. The pieces of space junk measuring 10cm or more total some 5,000 metric tons, according to a report by NASA scientists. Even if space launches were halted now —-which will not happen-— the collection of debris would continue growing as items already in orbit collide and break into more pieces. Much of the debris results from explosions of satellites, especially old upper stages left in orbit with leftover fuel and high pressure fluids.
. . The most debris-crowded area is between 885 and 1000 km above the Earth, Liou said, meaning the risk is less for manned spaceflight. The Space Station operates at about 400 km altitude, and Space Shuttle flights tend to range between 400 and 600 km.
Jan 20, 06: Mysterious debris fields found far from the poles on Mars were made by glaciers, possibly formed just like glaciers are on Earth --by the buildup of snow, researchers said. The glaciers would have resembled those found on Earth in places such as Mount Kilimanjaro in Africa or the Andean peaks in South America. They probably formed when Mars was tilted on its side five million years ago.
. . Researchers were intrigued when spacecraft data showed curious rock-strewn deposits at the foot of some Martian volcanoes and mountains close to the equator.
Jan 20, 06: A NASA spacecraft built to explore two of the solar system's largest "aster"oids won't launch this year because the space agency is dealing with cost overruns and technical issues in the project. The planned summer launch of the Dawn spacecraft has been indefinitely postponed.
. . Even if NASA gives Dawn the green light, it would take another year for engineers to finish routine testing of the spacecraft. Dawn is part of a NASA program called Discovery that seeks to explore the solar system on what for NASA is considered a shoestring budget. The program includes the Stardust mission, which last week returned to Earth with samples of comet dust.
. . Dawn was supposed to be launched from Florida in June. Powered by an ion engine fueled by the xenon gas, it was to make a nine-year journey to Ceres and Vesta. Ceres, the solar system's largest asteroid at about 600 miles long, appears to have a warm surface and evidence of a weak atmosphere. Vesta is about 320 miles long and appears to have been resurfaced by basaltic lava. [or exposed by a collision...]
Jan 19, 06: Pristine comet samples returned this weekend by the Stardust spacecraft after a 4.7-billion-km journey wildly exceeded scientists' expectations. When the sample canister inside the capsule was opened, scientists could see with naked eyes small black rocks and other particles that had been trapped in the probe's gel-filled collection device. "We were totally overwhelmed by the ability to actually see this so quickly and so straight-forwardly", Brownlee said.
. . The samples were trapped in a substance called aerogel, which although it has the same ingredients as a glass window, is 99.9% air and has the lowest density of any solid substance.
. . The Stardust spacecraft lifted off seven years ago and aimed for a close encounter with Comet Wild-2, a relative newcomer to the comparatively warmer region of space between the orbits of Mars and Jupiter. The comet is believed to come from the Kuiper Belt region beyond Neptune, but had a close approach to Jupiter in 1974 which deflected the icy body into its new orbit. Because Wild-2 has not been circling near the sun for long, the comet is believed to contain most of its original materials.
. . Comets may have seeded Earth with the organic materials and water that eventually led to life. The same process may have happened on other planets, such as Mars, and may be happening today in other planetary systems.
. . The chunks of Stardust's aerogel contain "hundreds and hundreds and hundreds of tracks" from comet particle impacts, some of which may even end with a few atoms of water ice, Brownlee said. One hole, which ends with an embedded rock, is so large, you can nearly poke a finger in, Brownlee said. Scientists expect to get more than 1 million particles larger than one-millionth of a meter in diameter.
. . Once the samples are cataloged, NASA will begin distributing small amounts to researchers worldwide for analysis.
Jan 12, 06: It will be the fastest spacecraft ever launched, zooming past the moon in nine hours and reaching Jupiter in just over a year at a speed nearly 100 times that of a jetliner. Its target is Pluto —-5 billion km from Earth. And the New Horizons spacecraft could reach it within nine years. (as early as 2015)
. . It's powered by nuclear fuel that will produce 200 watts. New Horizons is loaded with seven instruments that will be able to photograph the surfaces of Pluto and Charon and examine Pluto's atmospheric composition and structure.
. . In recent years, astronomers have come to realize that Pluto's class of planetary bodies, ice dwarfs, isn't so odd after all. In fact, ice dwarfs are the most populous group in the solar system. Now, scientists have a chance to learn more about them and the origins of the planetary system.
. . [a counter-argument] "Just as a Chihuahua is still a dog, these ice dwarfs are still planetary bodies."
Jan 11, 06: New computer modeling shows that the planet Mercury might have formed in a hit-and-run collision that stripped off its outer layers.
. . Astronomers have long assumed that collisions played a huge role in planet formation. The early solar system would have been loaded with dust that became rock that became planets, the thinking goes. Computer models generally have objects sticking together to make ever-larger objects or, in large crashes, two objects might become gravitationally bound.
. . Asphaug and his colleagues, including UCSC professor Quentin Williams, figure there might have been 100 or so objects as large as Luna or Mars that played cosmic billiards in those early years.
. . Hit-and-run might also explain the widely varying composition of asteroids, including the chunks that fall to Earth as meteorites. Stony asteroids resemble the rocky crusts of planets, while others are rich in iron, like the core of a planet. The range of space rock compositions is not easily explained if they all formed from the same disk of debris. "Some asteroids look like small planets, not very disturbed, and at the other end of the spectrum are ones that look like iron-rich dog bones in space", Williams said. The hit-and-run scenario fits neatly with this diversity of compositions.
Jan 6, 06: A spacecraft has sent a laser signal to Earth from 24 million km away in interplanetary space. The Messenger probe exchanged laser signals with a US ground station partway through its journey to the planet Mercury. After arriving in 2011, the probe will orbit Mercury for a year to explore its atmosphere, composition and structure. The NASA craft is equipped with a laser altimeter that will map the topography of Mercury by timing the return of laser pulses fired at the planet.
Jan 3, 06: Nasa scientists have witnessed a rare explosion on Luna, caused by a "meteoroid" slamming into it. The blast was equal in energy to about 70kg of TNT and was seen near the edge of Mare Imbrium (the Sea of Rains). The object that hit the Moon was probably part of a shower of "taurids" which peppered Earth in late October and early November. Understanding lunar impacts could help protect astronauts when Nasa sends humans back to the Moon.
. . One of the astronomers who observed the impact estimates that it gouged a crater 3m wide and 0.4m deep. Rob Suggs of Nasa's Marshall Space Flight Center was testing a new 25cm telescope and video camera they assembled to monitor the moon for space strikes. On 7 November, his first night using the telescope, he observed one.
Jan 5, 06: A new study provides the best estimate to date of the diameter and heft of Pluto's moon Charon and suggests the satellite likely has no atmosphere. Charon is the largest known moon in relation to the size of its host planet. It is about half the size of Pluto and about eight times less massive. The new observations put Charon's diameter at between 1,207 and 1,212 km. Charon's density is 1.71 times that of water, which suggests its icy contents are just more than 50% rock, and about 10% less rock by mass than Pluto. Ironically, Charon's density is now known more precisely than that of Pluto.
. . Pluto is known to have a very thin atmosphere, based on other occultation observations. If Charon has one, the new observations indicate, its pressure would be less than one-sixth of a millionth of the air pressure at the surface of the Earth. That would be 100 times less than the air pressure at Pluto's surface.
. . The leading theory for the formation of Pluto and Charon, along with two other small moons recently discovered, is that one object collided into another and the system coalesced out of the remains.
Jan 3, 06: Earth-bound astronomers taking Pluto's temperature have confirmed suspicions that the planet is colder than it should be. It's thought that the planet's lower temperature is the result of interactions between its icy surface and thin nitrogen atmosphere.
. . Astronomers found that Pluto's average surface temperature was about 43 K (-382 degrees F) instead of the expected 53 K (-364 degrees F), which is what the temperature of Pluto's largest moon, Charon, is. Unlike Pluto, Charon has no atmosphere, so its surface temperature was what astronomers predicted based on its geological makeup and reflectivity.
. . Astronomers think Pluto's colder than expected temperature reading involves interactions between nitrogen ice on the planet's surface and the nitrogen gas that makes up its atmosphere. The two forms of nitrogen are in a constant state of careful flux: as Pluto moves away from the Sun, the nitrogen gas "condenses", freezing and falling back to the surface as ice. The opposite happens when Pluto is closer to the Sun.
. . Planets like Venus and Earth experience a natural greenhouse effect, where sunlight energy striking the surface is absorbed and used to heat the surface. On Pluto, the opposite happens. "Pluto is a dynamic example of what we might call an anti-greenhouse effect", Gurwell said. Instead of being absorbed and warming the surface, sunlight striking Pluto is used to convert nitrogen ice on its surface into gas. A similar process happens when humans sweat: the evaporation of sweat from the skin has a cooling effect because the evaporated water carries away the body's excess heat.
. . Pluto is located thirty times farther away from the Sun than Earth, about 5 billion kms, and receives only about 1/1000th of the light that our planet receives. Pluto's surface temperature varies widely because of its erratic orbit, which can send it as close as 30 astronomical units (AU), or as far away as 50 AU.
. . In October '05, astronomers announced the discovery of two tiny, new moons orbiting the planet, each one only 45 to 160 km in diameter.
Jan 1, 06: The nine basic ingredients that Christophe Lasseur, [ESA's biological life-support coordinator,] plans to grow on other planets are: rice, onions, tomatoes, soya, potatoes, lettuce, spinach, wheat and spirulina --all common ingredients except the last. Spirulina is a blue-green algae, a very rich source of nutrition with lots of protein (65% by weight), calcium, carbohydrates, lipids and various vitamins that cover essential nutritional needs for energy in extreme environments.
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