The meteor that exploded over Russia last month probably broke off an asteroid and collided with another space body millions of years ago, a scientist says.

"It was formed within an asteroid, separated from it, and then, tens of millions of years ago, it suffered a collision, receiving multiple cracks as a result," Erik Galimov of the Russian Academy of Sciences said Thursday.

The meteor entered the atmosphere and exploded Feb. 15, causing a massive sonic boom that blew out windows and damaged thousands of buildings around the city of Chelyabinsk, injuring over 1,500 people.

"It was because of the large number of cracks that it exploded so powerfully," Galimov, director of the academy's Vernadsky Institute of Geochemistry and Analytical Chemistry, told RIA Novosti.

More than 100 meteorite fragments that have been recovered along a 30-mile trail along the object's flight path, scientists said, with the largest weighing about 2.2 pounds.