SPRITES, ELVES, & THE SHUTTLE DISASTER
First, all the notes moved here from sci-news.html
Feb 12, 03: Shuttle engineers relied on scientific models involving impacts from chunks of foam 3 cubic inches in size. Officials believe the foam that struck Columbia was 1,920 cubic inches. 617 times as big, and possibly carrying some ice besides --which is vastly heavier and stiffer than foam.
Jan 19, 03: (pre-shuttle) Sprites are red flashes of electricity that shoot up from thunderclouds 20km into the ionosphere, and elves, which are glowing red doughnut shapes radiating 290 km, were photographed by astronaut Dave Brown on the sprite hunt's first orbit. The infrared is invisible to the naked eye. Until now, images of them have been limited to those taken from the ground or airplanes.
Oct 17, 02: An atmospheric phenomenon called "sprites" could be pumping 50 times more energy into the upper atmosphere than was previously thought, suggesting our understanding of the global atmosphere is incomplete, according to University of Houston space physicists.
. . Sprites are large, brief flashes of light that occur very high in the atmosphere above large thunderstorms. Instead of discharging toward the earth like lightning, sprites soar upward above a thunderstorm and occur immediately following strong lightning strokes. negative cloud to ground strokes produce a phenomenon that is not often observed from the ground, termed a sprite halo, which is basically a sprite precursor.
Dec 12, 2001: Rare flashes of light called blue jets soar high above thunderhead -- up to 30 miles above the planet -- in flashes that last less than a second. Their cousins, red sprites, are more common and only occur when there is active lightning below. Both have only been documented over the past decade and were first spotted by pilots, who were often not believed. A new computer model shows blue jets derive from multiple streamers of electrical energy rather than as a single glowing column. The finding, by Penn State researcher Victor P. Pasko and colleagues, confirms expectations. The work also shows the jets are cone shaped --just 1-2 miles across at the base, yet 5-6 miles at the top. Related "blue starters" don't travel as high. "Blue starters appear to be blue jets that never quite make it", says Pasko.
Feb 10, 03: The space shuttle Columbia broke up in a mysterious area of the upper atmosphere once so little understood and difficult to study that scientists dubbed it the "ignorosphere." It's also called the ionosphere, because of the presence of free electrons (ions). "We're discovering the middle atmosphere has a lot of electrical phenomena."
. . In the ionosphere, ultraviolet energy from the sun as well as cosmic rays from faraway stars separate electrons from atomic nuclei. The free electrons give the area a characteristic not unlike metal, in that it can reflect electromagnetic energy. These electrons also create strange electrical effects, with fanciful names like "elves," "sprites" and "blue jets." Until recently, they were largely dismissed as illusions, noticed only by bleary-eyed airline pilots.
. . The region is of particular interest not only because that's where the disintegration occurred but also because of a time-exposure image taken by an amateur astronomer showing a snake of purplish light corkscrewing through the shuttle's hot glowing trail as it crossed over California. All those phenomena are related to thunderstorms, which were not recorded in the area at the time of Columbia's descent.
Post-Shuttle: The federal Environmental Technology Laboratory in Boulder, Colo, has been listening to the sounds of ghostly electromagnetic phenomena in the upper atmosphere, dubbed sprites, blue jets and elves. For some time, scientists have speculated on whether these events could endanger airliners or returning spacecraft.
. . A study conducted 10 years ago for NASA found that there is a 1-in-100 chance that a space shuttle could fly through a sprite, although it concluded that the consequences of such an event were unclear. And in 1989, an upper-atmospheric electrical strike "shot down" a high-altitude NASA balloon 129,000 feet over Dallas.
. . The little-known infrasound project at the Environmental Technology Laboratory operates a network of sophisticated electronic ears that can pick up subaudible thuds of waves crashing on either coast of the United States and the hiss of meteors and spacecraft re-entering the atmosphere thousands of miles away.
. . Sound waves of this nature are called "infrasonic" and are below the range of human hearing but travel unimpeded for extraordinary distances. Arrays of infrasonic sensors in the high Colorado plains east of Boulder recently have been looking for the crackle of the ghostly electromagnetic events in the Earth's upper atmosphere.
. . Originally, it was thought that the electrical charges in the thin atmosphere 50 miles above Earth were too dispersed to create infrasound. But Los Alamos National Laboratories physicist Mark Stanley said that, on closer inspection, "we've seen very strong ionization in sprites" indicating that there were enough air molecules ionized to cause heating and an accompanying pulse --a celestial thunderclap, as it were.
. . Physicists have long jokingly referred to the lower reaches of the ionosphere --which fluctuates in height around 40 miles-- as the "ignorosphere," due to the lack of understanding of this mysterious realm of rarefied air and charged electric particles.
. . The family of "transient" electrical effects occupy this part of the sky, including sprites, which leap from the ionosphere to the tops of thunderheads, and blue jets, which leap from thunderhead anvils to the ionosphere.
. . Streamers of static electricity can travel these realms at speeds 100 times that of ground lightning, or 20 million miles an hour.
. . On June 5, 1989, before the first sprite was ever photographed, a NASA balloon carrying a heavy pack of instruments suffered "an uncommanded payload release" at 129,000 feet, according to Lyons. It landed in an angry Dallas resident's front yard.
. . Investigators found scorch marks on the debris and considered it one of the first bits of solid evidence that sprites exist. As a result of the accident, NASA no longer flies balloons over thunderstorms.
. . Ironically, the balloon was launched from a NASA facility in Palestine, Texas, one of the towns where debris from the space shuttle Columbia fell.
S.F. Chronicle: man's astounding photo: Mysterious purple streak is shown hitting Columbia 7 minutes before it disintegrated.
. . Top investigators of the Columbia space shuttle disaster are analyzing a startling photograph --snapped by an amateur astronomer from a San Francisco hillside-- that appears to show a purplish electrical bolt striking the craft as it streaked across the California sky.
. . The digital image is one of five snapped by the shuttle buff at roughly 5: 53 a.m. Saturday as sensors on the doomed orbiter began showing the first indications of trouble. Seven minutes later, the craft broke up in flames over Texas.
A Chronicle reporter was present when the astronaut arrived. First seeing the image on a large computer screen, she had one word: "Wow."
. . In the critical shot, a glowing purple rope of light corkscrews down toward the plasma trail, appears to pass behind it, then cuts sharply toward it from below. As it merges with the plasma trail, the streak itself brightens for a distance, then fades.
It shows a vivid, lightning-like discharge apparently crossing through the contrail's left side.
. . NASA investigators remain unconvinced the chunk of foam insulation that struck Columbia's heat-resistant tiles on takeoff led to its eventual crash, and are now considering the possibility the craft was struck by space debris while in orbit. The space shuttle typically coasts along at 15,000 mph in one of the relatively clean levels, close to the Earth's atmosphere. At the level the shuttle travels in, much of the debris left behind by earlier space flights or defunct satellites is enveloped by the atmosphere and burns up before it can do damage. if the shuttle struck something, "everybody would know. It would be loud."
. . A prime suspect remains the 2 1/2-pound piece of foam insulation that fell off an external tank and struck the shuttle near its left wing during the lift-off. The chunk, particularly if it was weighted down with ice [from the cold contents of the tank], could have done enough damage.
. . Single lost silicate tile could lead to a calamitous 'zipper effect'.
. . The Atlantis mission, in which the crew was instructed to make a protective re-entry, suggests there were at least options for an ailing shuttle to return safely.
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