The impact and recovery of asteroid 2008 TC(3)

• Published in: Nature (London) 2009-03, Vol.458 (7237), p.485-488
• Main Authors: Jenniskens, P, Shaddad, M H, Numan, D, Elsir, S, Kudoda, A M, Zolensky, M E, Le, L, Robinson, G A, Friedrich, J M, Rumble, D, Steele, A, Chesley, S R, Fitzsimmons, A, Duddy, S, Hsieh, H H, Ramsay, G, Brown, P G, Edwards, W N, Tagliaferri, E, Boslough, M B, Spalding, R E, Dantowitz, R, Kozubal, M, Pravec, P, Borovicka, J, Charvat, Z, Vaubaillon, J, Kuiper, J, Albers, J, Bishop, J L, Mancinelli, R L, Sandford, S A, Milam, S N, Nuevo, M, Worden, S P
• Format: Article
• Language: English
• ISSN: 1476-4687
• DOI: 10.1038/nature07920

In the absence of a firm link between individual meteorites and their asteroidal parent bodies, asteroids are typically characterized only by their light reflection properties, and grouped accordingly into classes. On 6 October 2008, a small asteroid was discovered with a flat reflectance spectrum in the 554-995 nm wavelength range, and designated 2008 TC(3) (refs 4-6). It subsequently hit the Earth. Because it exploded at 37 km altitude, no macroscopic fragments were expected to survive. Here we report that a dedicated search along the approach trajectory recovered 47 meteorites, fragments of a single body named Almahata Sitta, with a total mass of 3.95 kg. Analysis of one of these meteorites shows it to be an achondrite, a polymict ureilite, anomalous in its class: ultra-fine-grained and porous, with large carbonaceous grains. The combined asteroid and meteorite reflectance spectra identify the asteroid as F class, now firmly linked to dark carbon-rich anomalous ureilites, a material so fragile it was not previously represented in meteorite collections.