How to escape from asteroids
About the threat of the fall of celestial bodies and the protection from it at TASS.
Meteorites that could pose a threat to humans, falling to the Earth relatively frequent. For the past 100 years in Russia there were at least two such hazardous events: fall of the Sikhote-Alin meteorite in 1947, whose fragments left in the soil of the crater to a depth of 6 m, and the explosion of the Chelyabinsk meteorite in 2013. Even earlier, in 1908, a much more powerful explosion occurred over the Tunguska forest and knocked down trees in the area of 2 thousand sq. km Number of researchers attributed this incident to the fall of a celestial body.
One of the most interesting areas of space research, the issue of protection from asteroids called on 23 July, the head of Roscosmos, Dmitry Rogozin. What cosmic body is dangerous and how to defend them, told TASS scientific Director of the Institute of astronomy of the RAS, Chairman of the expert group on space threats, Boris Shustov.
According to the scientist, humanity today, mainly thanks to the efforts of the United States, have revealed virtually all potentially dangerous celestial bodies larger than 1 km and the Detection of dangerous asteroids and comets, their study, evaluation of risks involved when NASA created a special unit — a Planetary Defense Coordination Office.
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The fall of an asteroid the size of 1 km would cause a global catastrophe, but “the likelihood of a collision with such a body is vanishingly small, and such threats are of practical interest,” said Shustov.
The real danger to the Earth and its inhabitants present the body small on a cosmic scale size is 50 m and less. In this range you will get, for example, the Tunguska and Chelyabinsk body. “According to the astronomical notions of the Chelyabinsk body is quite small (about 17 m), but see how it made some noise and even damage inflicted substantial,” said Shustov.
Although these relatively small meteorites can not trigger a global catastrophe of their falls occur more often. If a giant asteroid (kilometer-scale) can come to Earth every 10 million years, the Chelyabinsk body type can fall every 10-20 years, the scientist explained.
The representative of the RAS noted that now we have very little information on meteorites from 50 m and less.
We know where we are, unable to control, that is to predict the movement, to estimate the probability of collision for just 1% of dangerous asteroids with sizes of 50 m. But the bodies still smaller size as Chelyabinsk, we do not know almost nothing — they are too small to detect them at a distance.Boris Shustov, the scientific Director of the Institute of astronomy of the RAS, Chairman of the expert group on space threats area Real threat
Shustov noted that the residents of Chelyabinsk were very lucky, a meteorite entered the atmosphere on a shallow trajectory and exploded at a high altitude. “The explosion occurred at an altitude of about 24 km, so the consequences are not as serious as could be. If the body included a much steeper trajectory and the explosion occurred much closer to the Earth’s surface, few would have thought — the destruction and casualties would be terrible,” — said the scientist.
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The Chelyabinsk meteorite fell to Earth on 15 February 2013, in 80 km from the town of Satka Chelyabinsk region. According to the MOE, in many houses in Satka, and also in buildings of Chelyabinsk, front facing to the crash site, Windows were broken. Because the shock wave from the explosion of the meteorite in the city partially collapsed roof of a zinc plant. Asked for help more than 500 people, 34 people, including children, were hospitalized.
Pasha stressed that “the Chelyabinsk body were not discovered by any means until the enter the atmosphere because of its small size.” According to estimates of the RAS, the meteorite entered the atmosphere at a speed of 18 km/s, its mass was of the order of 10 kt, and the energy of the explosion to about 400 kt of TNT. For comparison, the power of the atomic bomb that destroyed Nagasaki, was 20 times less than 21 kt.
According to the Director of the Institute of astronomy RAS, Russia needs to create a system of detection of meteorites. “For now we mostly rely on the data that give us the American system, or working in cooperation with NASA,” said Shustov. While at the state level the problem of asteroid-comet hazard except the US is already doing in Europe and partly in Japan, South Korea and China. So, ten years ago the European space Agency was created by the unit Space Situation Awareness System, one of the areas of work which is the problem of detection of dangerous celestial bodies.