Russian fireball shows meteor risk may be bigger
Scientists studying the terrifying meteor that exploded without warning over a Russian city last winter say the threat of space rocks smashing into Earth is bigger than they thought.
Meteors about the size of the one that streaked through the sky at 42,000 mph and burst over Chelyabinsk in February - and ones even larger and more dangerous - are probably four, five or even seven times more likely to hit the planet than scientists believed before the fireball, according to three studies published Wednesday in the journals Nature and Science.
That means about 20 million space rocks the size of the Chelyabinsk one may be zipping around the solar system, instead of 3 million, NASA scientist Paul Chodas said at a news conference.
Until Chelyabinsk, NASA had looked only for space rocks about 100 feet wide and bigger, figuring there was little danger below that.
This meteor was only 62 feet across but burst with the force of 40 Hiroshima-type atom bombs, scientists say. Its shock wave shattered thousands of windows, and its flash temporarily blinded 70 people and caused dozens of skin-peeling sunburns just after dawn in icy Russia. More than 1,600 people in all were injured.
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