The Effects of an Extraterrestrial Impact with Planet Earth
By
Rob Astor
©1993 by Rob Astor
Comments & Suggestions Always Welcome.
robastor@hotmail.com
The impact of an asteroid or comet on planet Earth, in this day of advanced technology and complex social relations, could be the catalyst for the extinction of the human race, in much the same manner that the dinosaurs became extinct sixty-five million years ago (Next p8). Imagine for a moment that you are standing in a large city, like Miami, Florida for example. Let's say it's mid-day. There are people all around you. Traffic fills the streets. Skyscrapers gleam brightly, glass surfaces reflecting the brilliant sun. Salty ocean water fills the air. The blue of the Atlantic looks inviting in the summer heat. Bisecting the clear skies above is the white trail of a super-atmospheric stream, much like the exhaust of a jet, arcing downward with frightening speed. At the head is an ever growing, ever intensifying point of white light. You stare in horror, perhaps, possibly knowing the ultimate outcome of this extraterrestrial encounter. The object is an asteroid or comet, which traveled the icy realms of space to end its journey with a collision approaching speeds of fifteen kilometers per, second (Dinosaur!). At time zero, there is no sound, unless you were several hundred miles away. The body, maybe a few miles across, strikes Miami someplace near its center. There is a white flash of light so blinding, your retinas burn out. And, it's so hot, you are incinerated instantly (Dinosaur!, Final). However, let's pretend you can be an observer and witness exactly what has happened. When the chunk of space debris contacted the city, atmospheric friction generated white-hot heat, causing the object to explode as it burrowed into the relatively colder ground. There is the thermal flash of detonation equal to a few hundred nuclear warheads (Dinosaur!). Everything, for a mere instant, looks like a photographic negative. The thermal radiation thrown off by the flash ignites all combustible materials surrounding the epicenter. Clothing, drapes, wood, plastics, paper, fuels; even human skin begins to burn as flames leap outward wildly from the heat. The white flash dissipates leaving a huge orange fireball drifting lazily up, followed by the initial shockwave of the explosion. It's so powerful that it exceeds five million pounds per square millimeter, much stronger than needed to completely rip human flesh off of its skeleton. Buildings shatter like clay pigeons. Glass shatters, blown like missiles from the extreme pressure. The glass itself becomes a deadly factor because of its speed and shearing potential. Splinters could easily pass through a person. Trees are snapped clean, some flattened against the ground. Bridges burst like cheap plaster. Pavement is stripped from the ground. Cars, buses, trains, boats, plane; all are scattered like a tantrum-throwing child discarding unwanted toys. Violent winds pick up debris and hot winds set all that is left on fire. Even nearby fuel refineries explode from the heat and flame, setting off secondary explosions which include gas mains and fuel pumping stations (Final). The shock waves continue rippling outward, leveling everything for a radius of five hundred miles (Dinosaur!, Apocalypse p36). As the mushroom cloud rises, condensation rings form around it and suctions reverses the first effects of the blast. Trees bent over now snap back in the opposite direction. Debris is sucked up into the billowing red cloud. Wild static storms form, sending spasmodic flashes of red lightning careening through the air. Fiery rains begin to fall and evaporated water, super heated, combines with radioactive substances in the cloud, drenching the surrounding areas in black rain showers, polluting everything with fallout (Dinosaur!, Final). Had the actual impact happened in the ocean, giant tsunamis, one hundred and fifty stories tall, would've swept islands clean and flooded coastal cities, completely washing them away. The tidal waves would then continue to batter coasts for several weeks, churning the oceans, creating mud from loose sediments on the sea floors, destroying fresh water supplies inland (Apocalypse p36). If these two scenarios are not enough, had this impact taken place in a country that felt threatened or had inferior technology, the impact might have been mistaken as a aggressive nuclear assault. A nuclear war would be triggered (Apocalypse p134), creating havoc that could spell final annihilation for all life on Earth. As the blackened mushroom cloud spreads out, its shell of dust slowly begins to encircle the Earth. The planet's ability to cleanse its atmosphere with rain is now completely overwhelmed. The sun is cut off. Temperatures begin to fall. Plants die which cause animals to die and pollution fallout from the cloud affects every part of the globe. Marine life dependent on sunlight dies which causes larger marine creatures to die. Massive famine and drought follow in the wake of the nightmare of nuclear winter. Radioactive snows fall within the first few days after this catastrophe spreading radiation poisoning and sickness (Dinosaur!, Final). Eventually civilization falls (Apocalypse p134). The picture painted here is dismal. However, this has happened in Earth's past. This is the generally accepted theory of how the dinosaurs became extinct sixty-five million years ago (Crater pD1). Iridium contents in sedimentary rocks of the late Cretaceous suggest that this actually killed off all major forms of life, some seventy-five percent at that time (Dinosaur). Iridium is a rare element on Earth but, readily found in asteroids. If an asteroid about ten miles across collided with our planet, this could account for the sudden rise of iridium at this geological boundary. The clays are rich in iridium but not in soils deposited before or directly after the cataclysm (Dinosaur, Dinosaur!). This rise of this element led to the discovery of the crater thought to be responsible for the dinosaurs' demise. It's a 111 mile across crater a mile and a half under the Yucatan Peninsula in Mexico. A sister crater was found in Iowa that's twenty-two miles wide. The dinosaurs were actually done in by a double impact (Crater pD1). A question that might be asked from this is, "Where does this space material come from?" Astronomers have hypothesized that a huge cloud of comets exists in space about two light-years from the sun. They have further theorized that a dark companion of our sun, tentatively named Nemesis, orbits our star once every twenty-six million years. When this "death star" passes through the Oort Cloud, gravitational interaction causes some bodies to swarm into the inner solar system, sometimes pelting the planets Mercury, Venus, Earth and its moon, and Mars. Geological study of strata show that, on the average, Earth has experienced mass extinctions once every twenty-six million years and major impacts once every seventy million years (Dinosaur!, Dinosaur! p178). NASA has set up Program Spacewatch to look for Earth-grazing objects in a bid to prevent a major impact at some point in the future. On March 23, 1989, an asteroid named 1989-FC passed by the Earth at a distance of only twice that of the moon. At the time, this was the closest any major asteroid had ever passed our planet. Estimates of orbital trajectories concluded 1989-FC could impact either the Earth or moon in the next thirty years (Apocalypse p36, Next p8, Unexpected p287). Program Spacewatch is designed to launch nuclear devices into space to nudge an approaching body into another more desirable orbit, deflecting it away from Earth (Apocalypse p134, Next p8). When this was presented to a symposium of world leaders, the program wasn't considered a major concern because the chances of a major impact in the next fifty years are one in 6,000. The argument given was that there would be enough time to avert this danger. Governments are more concerned with politics and borders; thinking along narrow-minded terms instead of preparing for the future which reflects in all of today's society (Next p8). Waiting decades to take action would be tantamount to suicidal genocide. Has the human race become the dinosaur? Works Cited
"Apocalypse, How?" Omni. Volume 12: Page 36 + 134, December 1989.
"Crater Fills Hole in dinosaur Extinction Theory." USA Today. Page D1, July 9, 1992.
Dinosaur. The New Grolier Multimedia Encyclopedia. Macintosh CD-Rom Disc. 1992.
Dinosaur! Videocassette. PBS Video,1992. Running Time: 56 minutes.
The Final Chapter? Videocassette. Director: Wally Longul. Sony
Video Software Company, Inc. 1988. Running Time: 100 minutes.
"The Next Doomsday Impact." Astronomy. Volume 17: Page 8. November 1989.
Norman, David. Dinosaur! New York: Prentice Hall General Reference, 1991.
"Unexpected Asteroid: A Close Call From Space." Science News. Volume 135: Page 287. May 6, 1989.
Selected Bibliography
"An Asteroid Whizzes Past Earth." Sky & Telescope. Volume 78: Page 30, July 1989.
"Apocalypse, How?" Omni. Volume 12: Page 36 + 134, December 1989.
"Crater Fills Hole in dinosaur Extinction Theory." USA Today. Page D1, July 9, 1992.
"Did Impacts Help Dinosaurs Thrive?" Science News. Volume 141: Page 91, February 8, 1992.
Dinosaur. The New Grolier Multimedia Encyclopedia. Macintosh CDRom
Disc. 1992.
Dinosaur! Videocassette. PBS Video,1992. Running Time: 56 minutes.
The Final Chapter? Videocassette. Director: Wally Longul. Sony Video Software Company, Inc. 1988. Running Time: 100 minutes.
"The Next Doomsday Impact." Astronomy. Volume 17: Page 8. November 1989.
Norman, David. Dinosaur! New York: Prentice Hall General Reference, 1991.
"Unexpected Asteroid: A Close Call From Space." Science News. Volume 135: Page 287. May 6, 1989.
Sail of a Dimetrodon
By
Rob Astor
©1993 by Rob Astor
Comments & Suggestions Always Welcome.
robastor@hotmail.com
The Dimetrodon was a reptile that lived before the dinosaurs. They were a major life form on dry land between 300 - 250 million years ago. The lizard-like mammals were characterized by a large "sail" on their backs which might have served many purposes, including regulation of body temperature and the attraction of potential mates. The actual sail was a complex "organ." It had boney spines, skin where the Dimetrodon's blood traveled through and joints allowing the animal to flex the sail in various ways. Dimetrodon was a flesh eater. Lizards are cold-blooded creatures and require sunlight to warm their bodies to allow for more rapid movement. Dimetrodon's sail could be turned into the sun where the blood was warmed, thus helping warm the animal's entire body more quickly than many of Dimetrodon's favorite prey. Joints allowed the sail to move to near right angles with Dimetrodon's spinal column. When the lizard grew too warm, the sail could then be dipped into water to cool the blood and, thus help cool its body in the same way the sun warmed it. Although no dinosaur skin has ever been recovered from fossil digs, it isn't beyond the realm of possibility that Dimetrodon's sail may have been brightly colored or molted to help attract mates. Many modern day lizards share these characteristics. Colors would have been an asset since it is widely believed that Dimetrodon was a very temperamental creature. Dimetrodon might have needed all the help it could get in finding a mate to produce offspring. During its time on the Earth, Dimetrodon was a specialized creature. It warmed and cooled itself faster than other developed organisms and probably sported a variety of bright colors to attract other Dimetrodons.
Pygmy T-Rex
By
Rob Astor
©1992 by Rob Astor
Comments & Suggestions Always Welcome.
robastor@hotmail.com
Taken from August 1988 issue of Discover from the article "The Case of the Pygmy Tyrant" by Shawna Vogel.
Robert Bakker at the University of Colorado at Boulder thought the small skeleton of Gorgosaurus at the Cleveland Museum of Natural History didn't look right since 1942. He finally got permission to examine the skeleton in 1987. He consulted with Philip Currie at Tyrrell Museum of Paleontology in Drumheller, Alberta. The skull was not that of a Gorgosaurus but an advanced Tyrannosaurus Rex. There were some characteristics that weren't common in predators. Stereoscopic vision, common in predators, was present in the Tyrannosaurus. Information compiled with Michael Williams led them all to call it the "Pygmy Tyrant." This animal was actually Nanotyrannus, the only remainent of this genus. Both members are of the Tyrannosauridae family. Both species were different but evolved closely alike. They had traits that made them the most advanced meat eaters. Tyrannosaurus and Nanotyrannus had a snout bent perpendicular to their necks; this trait missing in more primitive carnivores. This gave them stereoscopic vision, the ability to look forward and downward at the same time with both eyes at once. They also had "Herculean" neck muscles that enabled them to nap at prey. Both hunted Triceratopses where a downward blow was essential to avoid the horns and frills of the Triceratopses. They also had chambers in their heads, which stored air and actually cooled their brains. The air could be moved from the lungs and into these chambers for that purpose. The Troodon are most like modern day birds. And, the definitive line between them and birds is virtually nonexistent. Birds are actually dinosaurs; the only member of that family to survive into modern day periods. And, it is thought that birds were around long before the dinosaurs, making them even older than the tyrants.
Hatchling Dinosaurs
By
Rob Astor
©1992 by Rob Astor
Comments & Suggestions Always Welcome.
robastor@hotmail.com
Taken from August 1988 issue of Discover from the article "Bringing Up Baby" by Pat Shipman.
Jack Horner won the MacArther "genius" award, which consisted of $1,000 for each year of his life for the next five years. His only focus in life was trying to understand dinosaurs. Jack helped paleontologists see the extinct animals as living animals as opposed to skeletons and artifacts that needed to be studied for face value. Some dinosaurs were agile, speedy and smart. Others were warm blooded and born alive instead of being hatched. There were also those that were very bird-like and some that lived in well-organized social groups. Jack unearthed complete embryos of dinosaurs at "Egg Hill" in Montana. Through his studies, he found different species of dinosaurs had different upbringings. Some were helpless while others had to fend for themselves at birth. The egg/nest density found also suggested some dinosaurs lived in colonies. The proximity of the eggs also showed site fidelity. Hypsilophodontis laid their eggs in the same place year after year. These dinosaurs may have protected the eggs with rotting vegetation like modern day crocodiles do their eggs. The tops of these eggs all pointed to the center of the nest and had an even distance from each other, the bottoms facing outward. Speculation suggests that the mothers moved the eggs with their forearms instead of moving each time to lay another egg. The reasons for this pattern are unknown. Hadrosaurs had boney crests atop their skulls. There were several chambers that may have been used to communicate with one another. This genus was called Maiasaura meaning "good mother lizard." The mothers had to feed their young, the siblings being helpless from birth. They stayed close to the nests and sometimes, were crushed underfoot. They also had some form of social behavior. The only skeletons found were those of very young or mature animals. This evidence suggests that the miniature adults migrated from the nest at a certain size and began new colonies. Orodromeus grew up fast. Their bones at birth were more well developed and they may have been able to run shortly after hatching. Troodon was a small carnivore that laid eggs in straight lines near the colonies of Orodromeus. The newly hatched Troodon were near the victim's colony and fed rather well. This also suggested that the parent Maiasaurs protected their young.