The recovery of asteroid 2008 TC₃

Abstract

Abstract-On October 7, 2008, asteroid 2008 impacted Earth and fragmented at 37 km altitude above the Nubian Desert in northern Sudan. The area surrounding the asteroid's approach path was searched, resulting in the first recovery of meteorites from an asteroid observed in space. This was also the first recovery of remains from a fragile ''cometary'' PE = IIIa ⁄ b type fireball. In subsequent searches, over 600 mostly small 0.2-379 g meteorites (named ''Almahata Sitta'') with a total mass 10.7 kg were recovered from a 30 · 7 km area. Meteorites fell along the track at 1.3 kg km )1 , nearly independent of mass between 1 and 400 g, with a total fallen mass of 39 ± 6 kg. The strewn field was shifted nearly 1.8 km south from the calculated approach path. The influence of winds on the distribution of the meteorites, and on the motion of the dust train, is investigated. The majority of meteorites are ureilites with densities around 2.8 g cm )3 , some of an anomalous (porous, high in carbon) polymict ureilite variety with densities as low as 1.5 g cm )3 . In addition, an estimated 20-30% (in mass) of recovered meteorites were ordinary, enstatite, and carbonaceous chondrites. Their fresh look and matching distribution of fragments in the strewn field imply that they were part of 2008 TC 3 . For that reason, they are all referred to as ''Almahata Sitta.'' No ureilite meteorites were found that still held foreign clasts, suggesting that the asteroid's clasts were only loosely bound.

Internal structure and physical properties of the Asteroid 2008 TC3 inferred from a study of the Almahata Sitta meteorites

“…The list of the samples is provided in Table 1. The sample codes correspond to the catalogue in Shaddad et al (2010).…”

“…Most of the recovered meteorites are classified as ureilites (Jenniskens et al, 2009). However, a significant number of pieces of various chondritic compositions have been found within the recovered meteorites which most likely also originated from the Asteroid 2008 TC 3 impact (Bischoff et al, 2010;Kohout et al, 2010;Shaddad et al, 2010;Zolensky et al, 2010) revealing significant compositional heterogeneity of the 2008 TC 3 asteroid.…”

Cosmic-Ray Exposure Ages of Meteorites

“…Almahata Sitta. Astronomers detected asteroid 2008 TC 3 about 19 h before it fell as the meteorite Almahata Sitta in the Nubian Desert of Sudan (Shaddad et al, 2010). Subsequent efforts recovered more than 600 fragments, most of them ureilites, with a mass of more than 10 kg.…”

Shape estimation for Košice, Almahata Sitta and Bassikounou meteoroids

“…Here we present results based on 3 cases, namely: Košice, Bassikounou and Almahata Sitta. The respective data can be found in (Buhl & Baermann 2007;Shaddad et al 2010;Gritsevich et al 2014). All mass distributions exhibit common features of undersampling for small fragments and exponential cutoff for a finite size effect.…”