MOSCOW, July 18, Tatyana Pichugina.Every week, dozens of space objects fly within the Earth's orbit. For example, one of these days there will be a rapprochement with a 700-meter asteroid. In total, there are almost one and a half thousand on the list of potentially dangerous ones. The famous Apophis is not among them, the risk of a collision with it is considered minimal by scientists.
Planet Destroyer
In the summer of 2004, astronomers from the Kitt Peak National Observatory in the USA, who studied the sky in search of near-Earth objects, they saw an asteroid. Nothing remarkable: the size is a few hundred meters, the distance is 170 million kilometers. There are many. It was forgotten and rediscovered in December by the Australians.
This time the object was observed by many observatories, which made it possible to calculate the orbit. It turned out that it is approaching the Earth, it has a small interorbital distance (0.002 astronomical units). According to calculations, on April 13, 2029, it will fly very close to the Earth. The probability of a collision is 3.3 percent. «This is the most dangerous asteroid known. Everyone was scared,» recalls the discoverer Farbrizio Bernardi. It was then that the object numbered 99942 received the name Apophis in honor of the ancient Egyptian deity — the destroying serpent.
At the moment of closest approach, the distance will be reduced to six earth radii — 38 thousand kilometers. This is the height of the orbit of geostationary satellites. It will be like a bright star in the sky.
Scientists fear that the orbit of Apophis will change and the next time it will not miss the Earth.
According to Nikolai Zheleznov, a senior researcher at the Institute of Applied Astronomy of the Russian Academy of Sciences, such as Apophis, 300-meter bodies are guaranteed to reach the Earth's surface. Its appearance in the atmosphere will cause an explosion a thousand times more powerful than the Chelyabinsk meteorite. When falling, it will destroy a territory comparable in area to the Russian region, and if it hits the ocean, it will cause a devastating tsunami that will circle the planet several times.
Get closer to explore
Astronomers are waiting for Apophis to get closer so they can study it better. They are going to send an automatic OSIRIS-REx station to him. After returning from the asteroid Bennu in September, she will have enough fuel to maneuver. The station instruments are able to determine the mineral composition, look for water, organic compounds, identify any materials of external origin on the surface, including particle emissions. You can also explore the Yarovsky effect — the acceleration of an asteroid under the influence of solar heat.
Russian scientists also plan to send the Spektr-RG space observatory to Apophis after the completion of its main mission. Now the device is located at the Lagrange point L2, the X-ray telescope ART-XC is operating. Telescope of German colleagues eROSITA is disabled. «Spektr-RG» is able to approach Apophis at any distance and then return to its original position. Close observation of it will help, in particular, to clarify its mass. Now it, like the diameter, is calculated approximately.
We do not know how to take an asteroid out of orbit, but we have the means of destruction, says Nikolai Zheleznov. We'll have to launch a missile with a nuclear warhead. In this case, a swarm of small debris will fall to Earth. data-crop-width=»600″ data-crop-height=»263″ data-source-sid=»» class=»lazyload» lazy=»1″ />
Chances are not zero
Total, according to dataNASA, more than 32 thousand near-Earth objects are known, of which about two thousand are over 140 meters in size. They are considered potentially dangerous. If the probability of a collision is not zero, the asteroid is included in a special list. But in any case, the risk of disaster is extremely small.
There are 1493 objects on the list of potentially dangerous asteroids of the European Space Agency. The first line is occupied by a body with the designation 2001VB, which will fly by at a distance of 0.015 astronomical units from the Earth on July 23. The probability of a collision is negligible — one chance in 356 million. However, the impressive size of the object, about seven hundred meters, causes concern. It's better to keep an eye on it.
It is curious that the asteroid Apophis has been crossed off the list of threats to the Earth this century. The fact is that during the flight on March 6, 2021, its orbit and position were specified. They found that even if something changes during the approach in 2029, the probability of a collision again — in 2068 — is almost zero.
Apophis remained on the list for 17 years due to its massiveness. Most asteroids are much smaller. Now there are 1493 objects, and not one more than a kilometer. The largest of those whose orbit crosses the earth is not there — 2022 AP7. Its dimensions are estimated to reach 2.3 kilometers. This is enough to destroy an entire continent.
Such risks should be considered in the longer term, US scientists believe. The more centuries included in the calculation, the higher the uncertainty with the orbit. Approximately a thousand bodies larger than a kilometer fly close to the Earth. Estimates that a maximum of 150 of them (and most likely about 40) in the next thousand years will converge to a distance of less than 0.01 astronomical units (3.89 distances to the Moon). Moreover, four objects will fly even closer: 7482 (1994 PC1), 68950 (2002 QF15), 164121 (2003 YT1), 144332 (2004 DV24), so they need special attention.