The meteor that exploded over the Ural Mountains in central Russia, Friday, injuring more than 1,000 people is the largest to hit Earth in a 100 years, NASA said in a report.

Earlier, NASA had confirmed that the Russian meteor was not part of the asteroid 2012 DA14 that passed the Earth on the same day but was an independent mass with its own trajectory. In a latest report on the Russian meteor, NASA said that the meteor was much larger than the initial estimate.

“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,” NASA said.

The new estimates also show that the meteor released 30 kilotons more energy than the previously estimated 470 kilotons of energy during its explosion and it took 32.5 seconds for the meteor to explode after entering the atmosphere. The data was based on the information collected by five additional infrasound stations located around the world -- the first recording of the event being in Alaska, more than 6,500 kilometers away from Chelyabinsk, NASA said.

"We would expect an event of this magnitude to occur once every 100 years on average," Paul Chodas of NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif., said.

The meteor exploded several miles above the Earth, sending sonic shockwaves and showering debris over a large stretch of region. Hundreds of houses and buildings were damaged by shockwaves generated by the explosion. The meteor explosion resulted in damages to the tune of $33 million and created panic waves across the region.

The debris hunters had flooded the region searching for the alien rocks that might have fallen to the Earth’s surface after the meteor explosion, while the scientists from Russia had retrieved fragments claimed to be from the meteor from a lake in the affected region.

NASA in its latest report confirmed the possibility of fragments reaching the Earth.

"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," Chodas said.

The Russian meteor is the largest reported to hit Earth since the meteor that hit the Tunguska region in Siberia in 1908. Asteroid 2012 DA14, which peacefully passed Earth Friday, hours after the Russian meteor explosion, had a slightly different trajectory and was about three times larger in size.