Meteor Blast on Earth

January 18, 2000 One of the most dramatic meteors in 10 years streaked across the skies of the Yukon Territory in Canada. Witnesses reported two sonic booms, a foul odor, and sizzling sounds heard all the way from Alaska through northwestern Canada. Based on readings from defense satellites and seismic monitoring stations, scientists estimate that the meteor detonated with the energy of two to three kilotons of TNT.
“I have never seen anything quite like this before,” said Joe Clarke of Marshlake, Yukon, who saw the meteor at 0845 PST (1645 UT) on January 18. “When it started, the flash lit up the mountains 15 km away as bright as daylight, then it just drifted across the sky. The contrail looked to me like the ones left by shuttle launches. It just hung there for at least 1/2 hour. [It's the] wildest thing I could ever imagine seeing.”

There was no major meteor shower on January 18. The Yukon fireball was probably what astronomers call a sporadic meteor. The inner solar system is filled with tiny dust particles that have bubbled off innumerable comets as they pass close to the Sun. These particles, called meteoroids, hit the Earth from random directions producing 2 or 3 sporadic meteors per hour every night.
Scientists from NASA and the Department of Defense are interested in the the Yukon event. Samples of dust or rock fragments from the explosion could reveal the origin of the meteoroid. Defense specialists would also like to know what the meteoroid was made of to help calibrate the sensors they used to detect the fireball.

On Friday, January 21 — just three days after the explosion — an Airborne Sciences ER-2 aircraft from NASA’s Dryden Flight Research Center flew to the Yukon Territory of northwestern Canada in an effort to collect atmospheric samples of the meteor’s lingering debris trail. The region, near the town of Carcross, is mostly unpopulated.

CREDIT: NASA