December 11, 2013

AN EARTH-SHATTERING KABOOM: Russian Meteor, from Birth to Fiery Death: An Asteroid’s Story.

Scientists have pieced together the history of the space rock that slammed into the atmosphere over the Russian city of Chelyabinsk on Feb. 15, creating a shock wave that injured 1,200 people. It’s a long, convoluted tale that picks up just after the solar system started coming together 4.56 billion years ago. . . .

Work published just a few months ago indicates that the Chelyabinsk asteroid was exposed to space just 1.2 million years ago, suggesting that yet another impact occurred around that time, Kring added.

This collision perhaps finalized the size of the space rock, which is thought to have measured about 65 feet (20 meters) wide when it entered Earth’s atmosphere.

“And finally, of course, we have one more collisional event, on Feb. 15, 2013,” Kring said.

While the Chelyabinsk asteroid met its end that day, other fragments of the LL chondrite still exist out in the depths of space. One such chunk is the 1,770-foot-long (540 m) asteroid Itokawa, which Japan’s Hayabusa spacecraft visited in 2005, gathering samples that were returned to Earth five years later.

Good thing that that fragment wasn’t the one that hit.