Image
© Victor Sharygin
When the Chelyabinsk meteorite streaked across the sky in February, it caused quite a bit of a stir in Russia. The resulting shockwave from its impact shattered glass, injuring over a thousand people. Now, scientists have found out a little bit more about this meteorite. Fragment of Chelyabinsk meteorite, showing the fusion crust -- the result of a previous collision or near miss with another planetary body or with the sun.
When the Chelyabinsk meteorite streaked across the sky in February, it caused quite a bit of a stir in Russia. The resulting shockwave from its impact shattered glass, injuring over a thousand people. Now, scientists have found out a little bit more about this meteorite.

The main body of the meteorite fell to the bottom of the Cherbarkul Lake near Celyabinsk. That's why in order to learn a little bit more about the meteorite, scientist examined fragments of the space rock. The fragments are composed of the same minerals as the main body of the meteorite, which means that the scientists could learn what they needed to know about the event.

So what did they find? It turned out that the meteorite had undergone an intensive melting process before being subjected to extremely high temperatures upon entering Earth's atmosphere. Based on the color and structure, the researchers were able to divide the fragments into three types: light, dark and intermediate. The lighter fragments were the ones that were most commonly found, but the dark fragments were found in increasing numbers along the meteorites trajectory, with the greatest number found close to where it hit Earth.

"The meteorite which landed near Chelyabinsk is a type known as LL5 chondrite and it's fairly common for these to have undergone a melting process before they fall to Earth," said Victor Sharygin, one of the researchers, in a news release. "This almost certainly means that there was a collision between the Chelyabinsk meteorite and another body in the solar system or a near miss with the Sun."

The dark fragments that the scientists analyzed included a large proportion of fine-grained material. Their structure, texture and mineral composition hinted at the fact that they were formed by a very intense melting process, revealing evidence of a potential collision.

"Of the many fragments we've been analyzing, only three dark samples show strong evidence of earlier metamorphism and melting," said Sharygin. "However, many fragments of the meteorite were picked up by members of the public, so it's impossible to say how large a portion of the meteorite was affected. We hope to find out more once the main body of the meteorite is raised from Cherbarkul Lake."

Currently, the scientists are continuing to research the meteorite. These latest findings were announced at the Goldschmidt conference in Florence on Aug. 27.