Ureilite-an
TKW 3.95 kg.
Pre-Earth-encounter size estimated to be 4.1 meters in diameter and 80,000 kilograms.
Observed approach: 6 October 2008
Observed fall: 7 October 2008
First found: 6 December 2008, Nahr an Nil, Nubian Desert, Sudan.
Many stones from this fall have been classified, with a wide variety of results - Ureilite, polymict, anomalous; bencubbin; EH 4/5; and EL 3.
From the MetBul:
On October 6, 2008, a small asteroid called 2008 TC3 was discovered by the automated Catalina Sky Survey 1.5 m telescope at Mount Lemmon, Tucson, Arizona, and found to be on a collision course with Earth. Numerous astronomical observatories followed the object until it entered the Earth’s umbra at Oct. 7.076 UTC the next day. The astrometric position of 295 observations of 2008 TC3 over the period Oct. 6.278 to Oct. 7.063 was used to calculate the approach trajectory over the impact location in northern Sudan. The object exploded at a high ~37 km altitude over the Nubian Desert, and as a result the meteorites are spread over a large area. A search was organized by the University of Khartoum on Dec. 2–9, led by P. Jenniskens (SETI Institute) and M. H. Shaddad (Khartoum).
    
Anne writes:
On October 6, 2008, Richard Kowalski (photo 1), an astronomer and member of the Catalina Sky Survey, was observing with the telescope on top of Mount Lemmon near Tucson, Arizona, when he discovered a small asteroid on a collision course with Earth. Many astronomical observatories followed its course, calculated the trajectory, and predicted that it would impact Earth somewhere in northeastern Sudan. Some twenty hours after its discovery, early in the morning of October 7, the small asteroid exploded high in the atmosphere and showered the Nubian Desert of northeastern Sudan with small fragments, just as predicted. With that information, a search expedition organized by the University of Khartoum quickly found a few kilograms of dark fine-grained, fragments with a thin fusion crust, a few kilometers east of Station Six (photo 2; Almahata Sitta in Arabic) on the railroad line connecting Wadi Haifa to Khartoum. |