The cover story in this week's Nature is about the meteorites found that can be tied directly to an asteroid impact with Earth, tracked by the team at UA's Mt. Lemmon Observatory. At first the UA team did not expect that any remnants survived as the asteroid was expected to burn up completely in the atmosphere over Sudan. But dozens of students searched the remote site and found 8.7 pounds of the asteroid 2008 TC3.
The meteorite is a class F, with iron, nickel, graphites, and nanodiamonds, probably formed by collisions in space.
[right, cover to this weeks issue, with the caption: "fragment of asteroid 2008 TC3 as found in the desert in northern Sudan in March 2009. The asteroid disintegrated at an altitude of 37 km in October 2008 but, remarkably, 47 fragments with a total mass of 3.95 kg have been recovered, and Jenniskens et al. have identified the material as surface matter from a class ‘F’ asteroid, a type not previously represented in meteorite collections. Credit: Peter Jenniskens/ SETI Institute."]