The national space agency, Roscosmos, said scientists believe
one meteoroid entered the atmosphere, where it burned and
disintegrated into fragments. Amateur video footage showed a
bright white streak moving rapidly across the sky before
exploding with an even brighter flash and a deafening bang.
According to NASA estimates, the meteor measured 55 feet (17
meters) across and had a mass of 10,000 tons. The space agency
put the amount of energy released in the meteor's explosion at
nearly 500 kilotons. By comparison, the nuclear bomb the United
States dropped on Hiroshima in 1945 released an estimated 15
kilotons of energy. The whole event, from the meteor's
atmospheric entry to its disintegration in the air above central
Russia, took 32.5 seconds, NASA said. Residents told CNN of
their shock as they saw, heard and felt the awesome blast, and
the chaos and confusion they witnessed in the moments afterward,
when no one knew what had happened. Denis Kuznetsov, a 23-year-
old historian from Chelyabinsk, told CNN vi