Science

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CNN/News 8 Austin

Mysterious Texas Fireball Fuels Worries About Space Debris

February 17, 2009 01:28 PM
by Emily Coakley
A fireball seen over the Texas sky this weekend was most likely a meteor, though some were concerned it was debris from satellites.

Officials Initially Feared Plane Crash

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On Sunday morning, many Texans saw a flash of light streak through the sky and heard a sonic boom. Officials in one central Texas county got so many calls about the light “that it sent deputies out in a helicopter to look for a plane crash,” the Associated Press reported.

Federal Aviation Administration officials said the Texas fireball was most likely a meteor. Several news outlets reported that the fireball was likely debris from two satellites that had collided in space last week, though an astronomer told the AP that wasn’t the case.

Preston Starr, who manages the University of North Texas’ observatory, said satellite debris would have been much smaller and moved slowly. “It would have looked like a blip, and nobody would be able to notice if it were a daytime entry,” Starr told AP.

He believes it was a meteoroid roughly the size of pickup truck, moving more than 15,000 miles per hour. He also said the object likely had “the consistency of chunk concrete.” Any piece that actually hit the earth would have been smaller than a fist, AP reports.

But another astronomer, interviewed by the Houston Chronicle, thought the falling object was much smaller than Starr’s estimate, and metallic.

Anita Cochran, who is assistant director of the McDonald Observatory at the University of Texas at Austin, told the Chronicle that she inferred from the sonic boom the fireball produced that the meteoroid was metallic.

Scientists may never know for sure. “Cochran said it’s almost impossible to triangulate the location of a meteorite from observations of its flight,” the Chronicle reported. Any discovery of the meteorite would likely be dumb luck.

The weekend incident, along with last week’s collision of two satellites, are signs of the growing problem of space junk. Later this week, the United Nations Committee on Peaceful Uses of Outer Space will meet in Vienna, where the issue of debris will be discussed, according to Sky News.

“There are an estimated 300,000 objects of more than 1cm in diameter orbiting the Earth, including roughly 12,000 satellites, of which only 6% are still functioning,” Sky News reported.

The satellite collision has prompted the European Space Agency to start work on its own space junk detection system. Right now, the agency uses NASA radars, which track about 13,000 objects orbiting the earth, Deutsche Welle reported.

Context: Cosmic collisions; asteroid detection system

Although small space debris hitting the earth often causes no major damage, collisions with larger objects could be devastating.

One of the most famous incidents of an asteroid hitting the earth is thought to have occurred near Tunguska in Siberia. A fireball erupted 12 miles into the sky on June 30, 1908, flattening an area of more than 2,100 square kilometers, though there was no crater or fragments of meteorites. The conditions led scientists to form several theories. According to findingDulcinea though, “The most widely accepted explanation is that a small comet or asteroid exploded 6 to 8 kilometers above the Earth’s surface.” The resulting explosion was approximately 1,000 times more powerful than the atomic bomb dropped on Hiroshima.

This past autumn, an asteroid about the size of a bus hit the atmosphere above Africa, renewing calls to create a system that would detect asteroids, meteoroids and other space debris before they hit the earth’s atmosphere.

Some scientists are concerned that an asteroid called Apophis is going to hit Earth in 2036. Apophis was first noticed in 2004, and is expected to pass within 20,000 kilometers of Earth in 2036, though the risk of it actually hitting the Earth is thought to be small.

Related Topic: Marfa lights

The Texas fireball joins another ongoing mystery in the Lone Star State. Outside the tiny west Texas town of Marfa, there are reports of unexplained lights. In a short documentary called “Marfa—Mystery Lights,” a town resident says scientists believe the lights originate in a nearby mountain range. The lights appear so regularly that the town has set up a viewing area with mounted binoculars.

Reference: Space objects defined

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