Asteroid-comet hazard
Hello.
In the wake of a message on Habrahabr about an asteroid flying past Earth, I would like to briefly tell you about the problem as a whole - the problem of asteroid-comet hazard (AKO).
In the solar system there are several hundred thousand known asteroids in science. It is assumed that the total number of objects with a radius of more than 1 km is about a million. Most of them are in the main asteroid belt (between Mars and Jupiter), some in the Kuiper belt (area beyond Neptune, Pluto, for example, is an object of the Kuiper belt, like some other dwarf planets - Haumea, Makemake), part of “flies free".
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The orbit of any object in the solar system has one important parameter - the perihelion distance. This is the minimum distance from the object to the sun. Asteroids approaching the Earth are usually called asteroids with a perihelion distance of less than 1.3 astronomical units . Depending on the parameters, they are also divided into three groups (more precisely, already into 4):
To assess the danger of asteroids, a graphic Turin scale was developed (an analogue of the Richter scale for earthquakes):
Horizontal is the probability of a collision, vertical is the kinetic energy of a collision in megatons. If the object is not 0 on the Turin scale, then this is very, very bad. Even a danger equal to one means the probability of a collision and almost complete confidence that the object will not burn in the atmosphere.
The most dangerous, at the moment, is the asteroid 99942 Apophis. He was discovered in 2004 at the Kit Peak Observatory. According to preliminary calculations, it turned out that it could collide with the Earth in 2029. As is often the case, it was “lost” for the time being, and after repeated detection, a collision in 2029 was practically excluded. However, after a series of additional observations and research, it turned out that he could “encounter” us, though a little later, in 2036, 2037 and subsequent years.
The name of the asteroid itself is symbolic. Apophis is the name of the not so good Egyptian god Apophis, pronounced in the Greek manner. With this, astronomers wanted to show that he would change his type after 2029. This asteroid received a record level of danger - 4 on the Turin scale. Subsequently, the danger decreased first to 1, and then to 0.
The asteroid itself has a diameter of about 150-300 meters, and, apparently, it "spins" near the Earth for a long time. The main problem associated with this asteroid is as follows: observational data (and there are already a lot of them - about 900 + several radar observations on the largest radio telescope Arecibo) are not enough to make an accurate prediction for 2036 and the following years. In 2029, Apophis will fly at a distance of 38,000 km from the center of the Earth (10 times closer than the Moon), and within its possible trajectories there is a so-called “keyhole” (keyhole) with a diameter of 600 meters, flying through which in 2029 an asteroid collides with Earth in 2036 (the probability of such a collision is 2-3 per 100,000). To eliminate the possible danger of this object, the accuracy is needed, which is practically unattainable by earthly observation tools.
In any case, it was this object that pushed astronomers' attention to the problem of asteroid-comet hazard. Indeed, since the days of dinosaurs in our planet nothing crashed, but according to statistics it is time.
2007 VK184 - the only object that currently has 1 on the Turin scale. Although the probability of a collision is quite low - 1 out of 2700. And the time of the collision “later” is 2048. While the observations of this object is small - about a hundred. Until 2014, another series of observations will be carried out and, possibly, it will remove all the questions regarding this asteroid and its “meeting” with the Earth.
There are also concerns (though not us, but our descendants) two objects - 101955 1999 RQ36 and 153814 2001 WN5. Their rapprochement with the Earth will be only after 2100, but in themselves they are several times more massive than both Apophis and 2007 VK184.
Asteroids sometimes collide with the Earth. Even in the 20-21 century there were several similar collisions: a Tungus meteorite, a meteorite in the Amazon Basin, Vitim bolide, etc. These objects mostly burned down in the atmosphere. In the case of an asteroid with a diameter of 100-300 meters, humanity is now fully capable of withdrawing the threat without Bruce Willis. There are several ways that it was supposed to (try) to try on Apophis or a similar asteroid:
In principle, with good luck (“good luck” = accurate mathematical calculation), a mass of 100-200 kg is enough to, for example, move Apophis to a safe distance. However, this should be done until 2020, after which it will be very, very difficult to change the asteroid's orbit.
Research on the problem of the asteroid-comet hazard has been conducted, is being conducted and will be conducted. Russia occupies one of the leading places in the world in this area. Serious studies are carried out at the Institute of Applied Astronomy of the Russian Academy of Sciences, at the Institute of Astronomy of the Russian Academy of Sciences, at the Pulkovo Observatory, at the Department of Celestial Mechanics of St. Petersburg State University, in Tomsk and other places. I am glad that the engineers of NPO. Lavochkin (where many satellites, rockets, etc. gather) also joined the problem and are ready to accomplish the tasks. NASA is conducting serious research, including space research. Constant monitoring of potentially dangerous objects is being conducted, new ones are being opened. Unfortunately, the earth observation facilities are often insufficient, therefore space missions are being developed. Nowadays, the methodology of working with such objects is being worked out, because 15-20 years ago it was only possible to dream of observing asteroids the size of Apophis. And one can hope that in case of a real danger, the world community will invent and implement a space protection program.
At the moment, it is possible to say with certain certainty that in the near future nothing big and very dangerous on Earth will fall, no matter how hard the film producers, Sitchiny, the yellow press and other filth.
I would like to finish with the phrase from “Hitchhiker's Guide to the Galaxy”: “Don't panic!”
Thank!
Note. The first drawing was prepared using the EPOS program (GAO RAS)
In the wake of a message on Habrahabr about an asteroid flying past Earth, I would like to briefly tell you about the problem as a whole - the problem of asteroid-comet hazard (AKO).In the solar system there are several hundred thousand known asteroids in science. It is assumed that the total number of objects with a radius of more than 1 km is about a million. Most of them are in the main asteroid belt (between Mars and Jupiter), some in the Kuiper belt (area beyond Neptune, Pluto, for example, is an object of the Kuiper belt, like some other dwarf planets - Haumea, Makemake), part of “flies free".
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Quick reference
The orbit of any object in the solar system has one important parameter - the perihelion distance. This is the minimum distance from the object to the sun. Asteroids approaching the Earth are usually called asteroids with a perihelion distance of less than 1.3 astronomical units . Depending on the parameters, they are also divided into three groups (more precisely, already into 4):
- Amur . These asteroids may approach the Earth, but they do not enter its orbit.
- Atons . Their orbits lie mainly inside the Earth's orbit and rarely go beyond
- Apollonians . Can penetrate the Earth's orbit
- X-asteroids . "Fly" in the orbit of the Earth
To assess the danger of asteroids, a graphic Turin scale was developed (an analogue of the Richter scale for earthquakes):
Horizontal is the probability of a collision, vertical is the kinetic energy of a collision in megatons. If the object is not 0 on the Turin scale, then this is very, very bad. Even a danger equal to one means the probability of a collision and almost complete confidence that the object will not burn in the atmosphere.
Dangerous asteroids
99942 Apophis
The most dangerous, at the moment, is the asteroid 99942 Apophis. He was discovered in 2004 at the Kit Peak Observatory. According to preliminary calculations, it turned out that it could collide with the Earth in 2029. As is often the case, it was “lost” for the time being, and after repeated detection, a collision in 2029 was practically excluded. However, after a series of additional observations and research, it turned out that he could “encounter” us, though a little later, in 2036, 2037 and subsequent years.
The name of the asteroid itself is symbolic. Apophis is the name of the not so good Egyptian god Apophis, pronounced in the Greek manner. With this, astronomers wanted to show that he would change his type after 2029. This asteroid received a record level of danger - 4 on the Turin scale. Subsequently, the danger decreased first to 1, and then to 0.
The asteroid itself has a diameter of about 150-300 meters, and, apparently, it "spins" near the Earth for a long time. The main problem associated with this asteroid is as follows: observational data (and there are already a lot of them - about 900 + several radar observations on the largest radio telescope Arecibo) are not enough to make an accurate prediction for 2036 and the following years. In 2029, Apophis will fly at a distance of 38,000 km from the center of the Earth (10 times closer than the Moon), and within its possible trajectories there is a so-called “keyhole” (keyhole) with a diameter of 600 meters, flying through which in 2029 an asteroid collides with Earth in 2036 (the probability of such a collision is 2-3 per 100,000). To eliminate the possible danger of this object, the accuracy is needed, which is practically unattainable by earthly observation tools.
In any case, it was this object that pushed astronomers' attention to the problem of asteroid-comet hazard. Indeed, since the days of dinosaurs in our planet nothing crashed, but according to statistics it is time.
2007 VK184 and other
2007 VK184 - the only object that currently has 1 on the Turin scale. Although the probability of a collision is quite low - 1 out of 2700. And the time of the collision “later” is 2048. While the observations of this object is small - about a hundred. Until 2014, another series of observations will be carried out and, possibly, it will remove all the questions regarding this asteroid and its “meeting” with the Earth.
There are also concerns (though not us, but our descendants) two objects - 101955 1999 RQ36 and 153814 2001 WN5. Their rapprochement with the Earth will be only after 2100, but in themselves they are several times more massive than both Apophis and 2007 VK184.
What to do?
Asteroids sometimes collide with the Earth. Even in the 20-21 century there were several similar collisions: a Tungus meteorite, a meteorite in the Amazon Basin, Vitim bolide, etc. These objects mostly burned down in the atmosphere. In the case of an asteroid with a diameter of 100-300 meters, humanity is now fully capable of withdrawing the threat without Bruce Willis. There are several ways that it was supposed to (try) to try on Apophis or a similar asteroid:
- Send a spacecraft to the asteroid and “push” it with the object so that the orbit of the latter changes slightly and stops passing through the Earth
- Direct the spacecraft to the object and a series of directed explosions to change its orbit
- "Flatten" an asteroid with another planet or satellite (for example, the Moon)
In principle, with good luck (“good luck” = accurate mathematical calculation), a mass of 100-200 kg is enough to, for example, move Apophis to a safe distance. However, this should be done until 2020, after which it will be very, very difficult to change the asteroid's orbit.
What's next?
Research on the problem of the asteroid-comet hazard has been conducted, is being conducted and will be conducted. Russia occupies one of the leading places in the world in this area. Serious studies are carried out at the Institute of Applied Astronomy of the Russian Academy of Sciences, at the Institute of Astronomy of the Russian Academy of Sciences, at the Pulkovo Observatory, at the Department of Celestial Mechanics of St. Petersburg State University, in Tomsk and other places. I am glad that the engineers of NPO. Lavochkin (where many satellites, rockets, etc. gather) also joined the problem and are ready to accomplish the tasks. NASA is conducting serious research, including space research. Constant monitoring of potentially dangerous objects is being conducted, new ones are being opened. Unfortunately, the earth observation facilities are often insufficient, therefore space missions are being developed. Nowadays, the methodology of working with such objects is being worked out, because 15-20 years ago it was only possible to dream of observing asteroids the size of Apophis. And one can hope that in case of a real danger, the world community will invent and implement a space protection program.
At the moment, it is possible to say with certain certainty that in the near future nothing big and very dangerous on Earth will fall, no matter how hard the film producers, Sitchiny, the yellow press and other filth.
I would like to finish with the phrase from “Hitchhiker's Guide to the Galaxy”: “Don't panic!”
Thank!
Useful links, literature
- Vinogradova, T. A., Zheleznov, N. B., Kuznetsov, V. B., and others. Catalog of potentially dangerous asteroids and comets. SPb .: IPA RAS, 2003.
- Nasa JPL Solar System Dynamics
- Wikipedia: asteroids approaching the Earth
- Nasa Asteroids approach the Earth (updateable)
- Nasa Dangerous Objects Catalog
- NeoDys - catalog of asteroids
Note. The first drawing was prepared using the EPOS program (GAO RAS)
Source: https://habr.com/ru/post/75645/
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