Russian meteor shows 20,000,000 space rocks threaten Earth, scientists warn
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The meteor that shocked Russia in February when it exploded in the skies above Chelyabinsk shows us that the danger from space rocks smashing into Earth is much bigger than previously thought, an international group of scientists has concluded.
The 20-meter-wide meteor, which streaked across the sky and exploded into small pieces on Feb. 15, smashing windows, damaging buildings and damaging residents’ eyesight, could have caused much more damage if it had been more solid, three studies published in US journals Nature and Science on Wednesday found.
After studying the area around the explosion and a wealth of video and other evidence over the last few months, NASA scientist Paul Chodas said the meteor blast showed that there were about 20 million space rocks whizzing around the solar system that could do serious damage to Earth – not the 3 million previously thought. That’s because it was considered that meteors had to be 30 meters and wider to cause huge devastation, but Chelyabinsk was actually a nearer miss than it seemed at the time, the scientists said.
Hundreds of videos recorded by car dashboard cameras were analyzed, which helped a great deal to verify the exact trajectory, speed and the energy of the meteor explosion that shattered windows in more than 3,600 apartment blocks, broke in doors and gates, in some cases collapsing roofs and knocking many pedestrians off their feet.
Over 1,200 people in the Chelyabinsk region were hospitalized that day because of the nuclear-like explosion.
According to the data now available, the Chelyabinsk meteor was traveling at a speed of 19 kilometers per second (68,400 kilometers an hour), was about a little bit less than 20 meters in diameter and weighed about 13,000 tons. Most of it burned up in the atmosphere and the huge emission of energy at the moment of the explosion, with no more than 0.05 percent (4-6 tons) of the debris of the space object reaching the surface of the planet.
Two groups of scientists published their studies in Nature, one led by Jirí Borovicka, of the Czech Academy of Sciences, the second led by Peter Brown, at the University of Western Ontario. Both calculated that the Chelyabinsk meteor explosion was equivalent to about 500 kilotons of TNT.
It has also been established that it is highly probable that the Chelyabinsk meteor was previously a part of a bigger space rock, two kilometers in diameters – an asteroid identified as (86039) 1999 NC43 that will pass several millions kilometers away from Earth in March 2014.
Brown’s group estimated the peak brightness of the explosion as 30 times brighter than the sun, which led to many, sometimes severe, cases of skin burns and eye retinas being damaged, as an estimated 70 people temporarily lost their sight because of the bright explosion.
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