March 30, 2009

Volume 87, Number 13

p. 11

Astronomy

Found Meteorites Could Aid Asteroid Studies

Unique rocks collected in the desert come from recent asteroid breakup

Elizabeth K. Wilson

Graced by astronomical serendipity, scientists now have in their hands the fragments of an asteroid they'd tracked, from its journey through space to its collision with Earth last October.

NASA

YONDER METEORITE Peter Jenniskens, a meteorite expert at the SETI Institute, in Menlo Park, Calif., spots a meteorite on the desert floor.

View Enlarged Image

Mauwia Shaddad

SKY SHOW The asteroid Almahata Sitta created bright trails as it burned up in the sky over Sudan, raining down meteorite fragments.

The meteorites—surviving remnants of the 80,000-kg asteroid—sprayed over the Nubian Desert in northern Sudan (Nature 2009, 458, 485).

Asteroids contain the best record of the origin of the solar system, but scientists have not been able to link them to the meteorites they've collected so far. The location, size, and composition of asteroids are needed to study their roles in solar system formation.

"We have 40,000 samples of meteorites, but we don't know where a single one of them came from," Michael E. Zolensky, a cosmic mineralogist at NASA's Goddard Space Flight Center, in Greenbelt, Md., said at a press conference held on March 24. "What???s different this time is that we know exactly which asteroid these meteorites came from," he said.

Astronomers followed the asteroid's trajectory as it broke apart in the atmosphere over the desert, then collected hundreds of the dark, fragile, and porous meteorites. The meteorites belong to a rare class known as ureilites.

"No one had to write a proposal" to find the meteorites, Lucy McFadden, an astronomer at the University of Maryland, College Park, said at the conference. "They landed right on our doorstep."

Chemical & Engineering News

ISSN 0009-2347

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