Many children were at lessons when the meteor fell at around 09:20 (03:20 GMT).
The agency's new gauge of the meteor's size was a marked increase from its initial estimate.
Scientists will likely rush to the site in Russia where the meteor was observed.
The Washington Post quotes the RAS of stating that the meteor was about 10 tons.
Roskosmos, Russia's space agency, said it was impossible to track objects falling as fast as the meteor.
Most of the meteor burned up before pieces hit the ground, scientists said.
To reconstruct the meteor's original orbit around the Sun, they used six different properties of its trajectory through Earth's atmosphere.
The space agency said observers at latitudes north of 51 degrees south should be able to see the meteor shower.
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Russian emergency officials said the meteor was destroyed after it partially burned in the lower atmosphere over the Ural district.
The meteor was several yards in diameter and weighed around 10 metric tons, Russia's Academy of Sciences said in a statement.
The meteor strike happened on the same day that near-Earth asteroid 2012 DA14 will make a close flyby of Earth.
Fragments of the meteor fell in a thinly populated area of the Chelyabinsk region, the Russian Emergency Ministry said in a statement.
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The space agency also increased the estimated amount of energy released in the meteor's explosion from about 300 to nearly 500 kilotons.
The whole event, from the meteor's atmospheric entry to its disintegration in the air above central Russia, took 32.5 seconds, NASA said.
The results suggest the meteor belongs to a well known family of space rocks - known as the Apollo asteroids - that cross Earth's orbit.
So there is no way the meteor and the asteroid are connected.
Using amateur video footage, they were able to plot the meteor's trajectory through Earth's atmosphere and then reconstruct its orbit around the Sun.
Most of these are related to the point at which the meteor becomes bright enough to cast a noticeable shadow in the videos.
In Russia, dozens of fragments of the meteor hit the ground, officials said, and search teams set out looking for meteorites outside Chelyabinsk.
The meteor was one yard in diameter, about the size of an exercise ball, when it entered the atmosphere over eastern Pennsylvania, said Cooke.
However, the US space agency Nasa said the meteor weighed 10, 000 tonnes before entering the atmosphere, and released about 500 kilotons of energy.
Traveling through the sky at a few kilometers per second, friction with the air can cause the meteor to break up into several pieces.
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However, the Washington Post has cited the European Space Agency as confirming that the meteor strike in Russia and 2012 DA14 are not related.
The Meteor T7 was bought by members of the Jet Age Museum - based at Gloucestershire Airport - which is due to open in August.
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So what is the probability that the meteor hits and the asteroid passes Earth on the same day when someone could record it on video?
"The meteor was probably about the size of an SUV, " said Donald Yeomans, manager of NASA's Near-Earth Object Program Office at the laboratory, in Pasadena, Calif.
The meteor event in Russia on Friday is a sobering reminder that space is a busy place, and that space rocks can take us by surprise.
In any year the biggest meteor is going to be small, in a thousand years the biggest meteor is going to be a thousand times bigger.
The European Space Agency said on their Twitter page Friday that the Russian meteor was not part of the larger meteor approaching Earth later this afternoon.
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Then it was on to the meteor that hit Russia, blowing out windows and injuring more than 1, 000 people in an unprovoked attack from outer space.
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