932
Asteroid 2012 TC4 may collide with the Earth in 2017
Photo of 10 October 2012. Gianluca Masi, Virtual Telescope Project. I>
Heavenly body size from 12 to 40 meters in diameter will pass near the Earth October 12, 2017 and, hypothetically, could face her c, the resource astrowatch.net. Data about asteroid 2012 TC4 were obtained in 2012, when the last time he walked past our planet. For comparison, astronomers lead Chelyabinsk meteorite, which fell in February 2013. Then suffered up to 1,500 people, and the shock wave damaged 7,000 buildings in the city. This heavenly visitor had a diameter of 20 meters, a new threat may be the same twice. At the same time, scientists have argued that the major causes for panic.
The last time an asteroid passed by Earth in 2012 at a distance of 0.247 LD (Lunar Distance), which is about 94,800 km. TC4 elongated orbit, and he has repeatedly passed near our planet. Now astronomers are trying to calculate its orbit and the possible proximity of the passage in 2017.
The probability of collision on the existing data is 0.00055%. The fact that the minimum distance from the ground to cross the orbits of celestial bodies and the earth shall be not more than 0.079 LD, only those objects are considered as potentially hazardous to our planet. But the probability of crossing orbits is still not zero, so write off TC4 is not necessary.
The main problem lies in the fact that astronomers can not fully appreciate the size of any object, or its composition. According to observations, TC4 can be from 10 to 40 meters in diameter. Dimensions of celestial bodies, astronomers estimate based on their brightness, but it is unknown asteroid surface reflection coefficient differs depending on the composition. If this is rocky ten-object, it just burn in the atmosphere and it will not even notice, and a 40-meter iron asteroid reaches the surface and leave a rather big crater at the crash site. To understand the size of a celestial body: FIFA recommended dimensions of a football field - 105 by 68 meters. According to astronomers asteroid TC4 can cause considerable damage, if it occurs in a populated area.
In NASA believe that the asteroid is not a threat, but it requires observation, as the 100% rule out the possibility of intersection of its orbit and the orbit of the Earth is impossible. If it is a large rocky asteroid, the consequences of his fall will be comparable to the devastation brought by a meteorite Chelyabinsk. For predicting the consequences of the fall of the iron body of this size (40 meters), scientists are not taken.
On April 12, 2015 and recorded under surveillance for 1572 potentially dangerous celestial bodies. The orbit of any known object does not intersect the Earth's orbit. Work on the detection of potentially dangerous objects does not stop and astronomers are finding new celestial bodies passing near the planet on a daily basis.
Source: geektimes.ru/post/248944/