Scientists at Urals Federal University in Yekaterinburg have examined 53 meteorite fragments taken from the perimeter of the hole in frozen Chebarkul Lake. The largest is only 7 mm (about a quarter-inch) across; the smallest about one millimeter. Many are covered with dark fusion crust, a layer of melted and blackened rock from atmospheric heating.
The little stones are a common type of meteorite called a chondrite (KON-drite) that originated in the crust of an asteroid. A long-ago impact sent a fragment of the asteroid flying toward the inner solar system where it ultimately encountered Earth last Friday.
The Russian meteorite, which may receive the name Chebarkul, after the lake and town where it was found, contains about 10% iron-nickel, magnesium-rich chrysolite and sulfite, all common materials found in stony meteorites.
Chondrites are classified according to their iron content. Those with 15-20% nickel-iron metal are iron-rich and named “H” chondrites. Meteorites with a 7-11% nickel-iron content are classified as “L” chondrites, and those with the lowest amount of iron are the “LL” variety. Based on the lab’s description, it would appear that the fireball left a trail of L-chondrite crumbs. Let’s hope the hunters and scientists can follow the trail to the bigger ones.
** Update: I’ve recently learned via Russia TV and the New York Times this morning (Feb. 19) that local people are finding hundreds of small fragments buried in the snow. Read the full New York Times article and see more photos HERE.