Weighing about 10,000 tons, the
meteor that exploded over Russia's Ural Mountains on Friday is the largest space rock to hit the Earth's surface in more than a hundred years, scientists say.
The meteor, which had a diameter of 55 feet, exceeded NASA's initial prediction.
"The estimated size of the object, prior to entering Earth's atmosphere, has been revised upward from 49 feet (15 meters) to 55 feet (17 meters), and its estimated mass has increased from 7,000 to 10,000 tons," a statement from the agency said.
Paul Chodas, of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory, told the
Wall Street Journal the meteor's size is uncommon.
"We would expect an event of this magnitude to occur once every 100 years on average," he said. "When you have a fireball of this size we would expect a large number of meteorites to reach the surface and in this case there were probably some large ones."
Before striking the surface, the meteor fragmented and sent miniscule pieces across the area, with one particularly large piece leaving a 50-foot hole in the surface of Chebarkul Lake, which was frozen.
Since Friday, 53 meteors fragments have been recovered from the lake by an expedition from Urals Federal University.
Locals have also been harvesting meteor fragments, which are considered extremely valuable, giving way to a black market in nearby impoverished Siberian towns.
Although no one died because of the meteor, more than 1,500 people were reportedly injured in the nearby industrial city Chelyabinsk, which has a population of about 1.13 million.
The meteor's blast created a shockwave, which created a blinding light and clouds of debris that swept through the city.
NASA estimates the blast to be equivalent to more than 30 Hiroshima bombs.
According to local health officials, 46 individuals remained hospitalized as a result of the meteor.
In addition to the injuries, Chelyabinsk faces massive property damage to its infrastructure amounting to more than $33 million in damages.