Aletai Meteorite Sphere

A SIZABLE IRON SPHERE FROM ONE OF THE LARGEST METEORITE STREWN FIELDS

This lot features a shimmering metallic sphere, extracted from the core of the famous Aletai meteorite, discovered in China's far northwestern province of Xinjiang. This sample allows a three-dimensional view of the meteorite's interior crystalline matrix, chiefly formed of the interweaving bands of two iron-nickel allows, taenite and kamacite — the latter of which is unique to meteorite specimens and found nowhere else on Earth.

Aletai is a member of one of the smallest subgroups of iron meteorites in the scientific literature, with only sixteen IIIE meteorites on record. Of these sixteen, only two have anomalous chemical abundances and Aletai is one of them, as it contains the highest concentration of gold in the IIIE group.

Aletai also contains a relatively large amount of iridium, the second densest element known. Because the abundance of iridium in meteorites is much higher than that found in the Earth's crust, it was the unusually large amount of iridium present in the 65 million-year-old Cretaceous–Paleogene boundary that sparked the idea that a massive meteorite impact was responsible for the extinction of the dinosaurs 65 million years ago.

The entire mass of Aletai is close to 100 tons, and a 28-ton Aletai specimen is the 5th largest single meteorite found on Earth. The strewn field was so vast — 430 km (267 miles) in length — that for some time different specimens from this meteorite shower had different names (Armanty, Xinjiang, and Ulasitai). As it has now been determined that each of these meteorites originated from the same event, they have all been renamed Aletai.

REFERENCES:

Meteoritical Bulletin Entry for Aletai