The probability of a collision of the Earth with a celestial body directly depends on the size of this body. In particular, a collision of a planet with an object larger than 1 km can occur approximately once every million years, said on February 15 in a commentary to Izvestia, an expert at the NTI Infrastructure Center Aeronet, associate professor, first deputy head of the Department of Dynamics and Flight Control of Rockets and Spacecraft, MSTU Vsevolod Koryanov.
“As the size decreases, the frequency of collisions increases, as the number of objects themselves increases (for example, objects with a size of 100 m can exist about 25 million units at a distance of the Earth’s orbit),” he said.
For humanity, it is precisely large celestial bodies larger than 20-30 m that pose a threat, the probability of collisions with which is much higher (once every tens to hundreds of years), the scientist pointed out.
As for countering the asteroid-comet threat, there are several basic concepts, Koryanov noted. For example, eliminating a dangerous celestial body before it collides with the Earth or changing its orbit in such a way as to avoid collision and deflection.
“One of the main areas of protection today is a direct kinetic impact. Also, changing the orbit of a dangerous celestial body can be done using the pressure of sunlight. To do this, it is enough to change the albedo of the asteroid or use mirrors to concentrate the sun’s rays on its surface,” explains MSTU associate professor.
Other approaches also exist, such as evaporating surface material using solar concentrators or lasers to create a reactive force that deflects a dangerous object.
“The concept of “space billiards” is also of interest. As part of it, it is proposed to use another celestial body to influence a dangerous object. A small near-Earth asteroid or its fragment can be used as such a body. Such an object is captured by a spacecraft, and due to the gravitational maneuver near the Earth, it is directed to a dangerous asteroid,” Koryanov said.
The problems of asteroid-comet hazard (ACH) are being studied by a large number of scientists from various countries. Further development of technologies and ways to counteract ACH will lead humanity to create a sustainable system of protection against space threats, as this is one of the priorities of mankind in ensuring the safety of its life on the planet, the expert concluded.
Earlier, on February 15, Boris Shustov, chairman of the expert group on space threats at the RAS Space Council, told Izvestia that a large asteroid that will approach the Earth on February 16 to a distance of 4.6 million km does not pose any danger. He noted that the larger the sphere around the Earth we consider, the more often even large cosmic bodies enter there.
On February 13, it was reported that Krasnodar astronomer Alexander Ivanov was able to take a picture of this asteroid. Experts are tracking a fairly large asteroid – its size is about 800 m. The approach of a celestial body to the Earth at a distance of up to 4.6 million km is expected on February 16. The asteroid is moving at a speed of 24.6 km/s.
