Similar to lot 48. Eucrites are volcanic rocks from outer space and Aouinet Legraa is one of only two unbrecciated eucrite witnessed falls. The lack of brecciation (the mixing of different rock types) is important to researchers as it eliminates confusion from the mixing of different materials. On July 17, 2013, at approximately 11 PM, an extremely bright fireball was seen in both Tindouf and Aum el Assel, Algeria. The next morning competing groups of meteorite hunters from the Sahrawi refugee camps of Tindouf ventured into the Sahara in search of the meteorite. These men did not have the tools available to their Western counterparts. There were no Doppler Radar reports nor an array of SkyCams that could assist in triangulating the location of the fall. Given the fragmentation of the fireball, the hunters were certain meteorites were on the ground — but where? After hundreds of square miles had been canvassed over a period of months, the meteorite could not be found. There were, however, consolation prizes that kept the searchers motivated: many other meteorites were discovered during the course of this search, including a strewn field of Martian meteorites now known as NWA 8656. In April 2014, fully nine months after the search commenced, in an area that had been randomly canvassed just prior to the fireball, the strewn field was finally located. Preserved by the Sahara, numerous stones with fresh black fusion crust were recovered from the tan desert sands. The leader of the meteorite-hunting expedition reported, “The men were so happy. The joy we had was nearly the same as what water brings when the need is most desperate…our finding this was not by chance, but the result of hard continuous work, and it is our endless passion for discovery which makes us free men.”

Scientific evidence indicates that this sample — and nearly all howardites, eucrites and diogenites (“HED” meteorites) — originate from the asteroid Vesta, the second largest asteroid in the solar system. These samples were blasted off Vesta after a smaller asteroid slammed into its surface. NASA’s DAWN spacecraft, which orbited Vesta in 2011, provided further confirmation of Vesta as the place of origin.

Exceedingly fresh, more than 90% of this meteorite is blanketed in pristine fusion crust — the result of melting during its transit through Earth’s atmosphere. This meteorite also features secondary crust as seen on the flat rippled face: this meteorite was part of a larger mass that broke apart in Earth’s upper atmosphere; the freshly broken surface melted and reglazed before the meteorite achieved terminal velocity and landed on Earth. In those spots where the crust is not present, a peek at the meteorite’s khaki-hued unbrecciated matrix is revealed. From the asteroid Vesta, this is an exceedingly rare unbrecciated eucrite. To see what Aouinet Legraa looks like under a microscope, see the next lot).

Christie's would like to thank Dr. Alan E. Rubin at the Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles for his assistance in preparing this catalogue.

(Image 2, the view of Vesta, not part of the lot. Image credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA).

75 x 51 x 49mm (3 x 2 x 2 in.) and 281.9g (0.66 lbs)