The impact and recovery of asteroid 2008 TC3
Peter Jenniskens
(1)
,
Muawia H. Shaddad
(2)
,
D. Numan
(2)
,
S. Elsir
(3)
,
A. M. Kudoda
(2)
,
Michael E. Zolensky
(4)
,
L. Le
(4)
,
G. A. Robinson
(4)
,
J. M. Friedrich
(5)
,
D. Rumble
(6)
,
A. Steele
(6)
,
Steven R. Chesley
(7)
,
Alan Fitzsimmons
(8)
,
S. Duddy
(8)
,
Henry H. Hsieh
(8)
,
G. Ramsay
(9)
,
P. G. Brown
(10)
,
W. N. Edwards
(10)
,
E. Tagliaferri
(11)
,
M. B. Boslough
(12)
,
R. E. Spalding
(12)
,
R. F. Dantowitz
(13)
,
Marek Kozubal
(13)
,
P. Pravec
(14)
,
J. Borovicka
(14)
,
Z. Charvat
(15)
,
Jérémie Vaubaillon
(16, 17)
,
J. Kuiper
(18)
,
J. Albers
(1)
,
Janice L. Bishop
(1)
,
R. L. Mancinelli
(1)
,
Scott A. Sandford
(19)
,
Stefanie N. Milam
(19)
,
M. Nuevo
(19)
,
S. P. Worden
(19)
1
Carl Sagan Center, SETI Institute
2 Department of Physics and Astronomy, University of Khartoum
3 Physics Department, Juba University
4 JSC - NASA Johnson Space Center
5 Department of Chemistry, Fordham University
6 Geophysical Laboratory, Carnegie Institution of Washington
7 JPL - Jet Propulsion Laboratory
8 School of Mathematics and Physics, Queen's University
9 Armagh Observatory, College Hill
10 UWO - University of Western Ontario
11 ET Space Systems
12 Sandia National Laboratories
13 Clay Center Observatory, Dexter and Southfield Schools
14 Astronomical Institute, Academy of Sciences
15 Czech Hydrometeorological Institute
16 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides
17 GAP - Groupe Astrométrie et Planétologie
18 Dutch Meteor Society
19 SETI Institute, NASA Ames Research Center, Moffett Field
2 Department of Physics and Astronomy, University of Khartoum
3 Physics Department, Juba University
4 JSC - NASA Johnson Space Center
5 Department of Chemistry, Fordham University
6 Geophysical Laboratory, Carnegie Institution of Washington
7 JPL - Jet Propulsion Laboratory
8 School of Mathematics and Physics, Queen's University
9 Armagh Observatory, College Hill
10 UWO - University of Western Ontario
11 ET Space Systems
12 Sandia National Laboratories
13 Clay Center Observatory, Dexter and Southfield Schools
14 Astronomical Institute, Academy of Sciences
15 Czech Hydrometeorological Institute
16 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides
17 GAP - Groupe Astrométrie et Planétologie
18 Dutch Meteor Society
19 SETI Institute, NASA Ames Research Center, Moffett Field
Résumé
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 554-995nm wavelength range, and designated 2008 TC3 (refs 4-6). It subsequently hit the Earth. Because it exploded at 37km 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 3.95kg. 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.