EarthSky // Science Wire, Space Release Date: Oct 08, 2013

Extensive laboratory studies of the Chelyabinsk meteorites revealed traces of ancient space collisions even more violent than the recent encounter with Earth.

Scientists from the Czech Republic, Finland, and the Russian Federation are presenting new findings today (October 8, 2013) on meteorites, or rocks from space, recovered after the Chelyabinsk fireball that exploded over Russia on February 15, 2013. The report is being presented to the American Astronomical Society Division for Planetary Sciences meeting in Denver, Colorado. The studies of these meteorites have revealed traces of other space collisions and serve as a reminder of the existing threat of asteroid impacts for our civilization, according to these scientists.

The results are of special interest because they not only shed light on potentially hazardous impacts of asteroids on Earth, but also on more violent space collisions which disrupted ancient protoplanets in the early solar system into smaller asteroids we observe today. Dr. Maria Gritsevich (Finnish Geodetic Institute and Russian Academy of Science) and Dr. Tomas Kohout (University of Helsinki, Finland, and Academy of Sciences of the Czech Republic) are presenting the report.

A cut-open Chelyabinsk specimen shows a light texture with darker patches of shocked or impact-melted minerals. When meteorite minerals like olivine are shocked by impact, chemical changes occur that make them darken. Photo by meteorite hunter Evgenij Suhanov. Photo and caption via AstroBob.

A cut-open Chelyabinsk specimen shows a light texture with darker patches of shocked or impact-melted minerals. When meteorite minerals like olivine are shocked by impact, chemical changes occur that make them darken. Photo by meteorite hunter Evgenij Suhanov. Photo and caption via AstroBob.

The Chelyabinsk daylight fireball, which crossed the sky over Southern Ural in Russia on February 15, 2013, was the largest extraterrestrial body impacting the Earth since the Tunguska event in 1908. The atmospheric entry of the Chelyabinsk asteroid was observed by many witnesses, and the associated air blast caused significant damage including numerous broken windows and partial building collapses in the city of Chelyabinsk and the surrounding territories.

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