Scientific American: Rock Science: First Meteorites Recovered on Earth from an Asteroid Tracked in Space.
Last October, asteroid monitors at the Catalina Sky Survey at the University of Arizona in Tucson picked up a small object on an immediate collision course with Earth. The asteroid was too small to present a real threat—just a few meters across, it stood little chance of penetrating the atmosphere intact. Indeed, it exploded in a stratospheric fireball over northern Sudan less than 24 hours later—an event witnessed by people on the ground as well as the pilots of a KLM airliner—conforming well to astronomer's predictions for its trajectory.
But the asteroid, dubbed 2008 TC3, was nonetheless a momentous discovery: Among the countless small objects that strike Earth's atmosphere every year, none had ever been detected and tracked before it impacted. Now the Sudan bolide has yielded yet another first: Researchers report in Nature today that they have recovered 47 meteorites from the object in the Nubian Desert. And lead author Peter Jenniskens, a meteor astronomer at the SETI Institute in Mountain View, Calif., says that another search completed earlier this month, after the paper was submitted, has upped the meteorite count to about 280.