Estimate of the impact probability of 2011 MD with Earth Friday, 24 June 2011 19:29
http://hainanwel.com/en/unusual-world/6 ... -2011.htmlAccording to NASA, on June 27, 2011 near Earth will fly asteroid 2011 MD. Although asteroid 2011 MD many media have already named the 18-meter asteroid, its adjusted size is only 8 meters, and the calculated mass of the asteroid is 810 tons. Asteroid 2011 MD was discovered only on June 22, 2011, so very little is known about its orbit, the Earth's gravity well can greatly change the asteroid's orbit, but it is expected, that the asteroid will pass near Earth at a distance of 12,000 kilometers.
It is very difficult to calculate the exact probability of a impact of asteroid 2011 MD with Earth, scientists still have only preliminary data. Let's try to explain them in simple examples.
Asteroids, or so-called minor planets have been discovered only in the 19th century. The first asteroid Ceres discovered by Italian astronomer Giuseppe Piazzi on the night of January 1, 1801. The size of the asteroid Ceres is approximately 950 km, which made possible the fact of his discovery at that time. After that, thousands of asteroids have been discovered very different sizes, by the way, a significant portion of them opened Soviet astronomers.
It is now established, that the solar system is a huge number of comets and asteroids, but most of them (about 98%) is concentrated in the main asteroid beltб that lies between Mars and Jupiter, the Kuiper belt and Oort cloud, which are pretty far beyond the Earth's orbit. Therefore, the Earth encounters with asteroids less than, for example, Mars.
But there are quite a few asteroids, which form the so-called Group of Apollo, the orbits that intersect Earth's orbit, and that these asteroids are a potential collision risk to Earth. There is also a danger on the part of the asteroids whose orbits are inside the orbit of the Earth- is the so-called Group of Aton, or beyond the orbit of the Earth, but far from it – is the so-called group of the Amur.
Astronomers have agreed to call asteroids, that approach the Earth at a distance of less than 7.48 million km-are a potentially dangerous objects, provided that the asteroid has a size of at least 150 meters, as it is believed that asteroids are smaller in the case of entry into Earth's atmosphere begin to disintegrate in the Earth's atmosphere and serious damage can not cause.
Thus, the asteroid 2011 MD only satisfies the first condition of the potentially hazardous asteroid, as if its entry into the atmosphere- will a very high probability of its destruction, but NASA specialists have calculated, that if the asteroid fragments will reach the Earth's surface, releasing energy equivalent to energy released during the explosion of 12 tons of TNT.
In order to more accurately estimate the probability of impact, use several scales. The best known is the Torino Scale, in which, depending on the asteroid, its mass and velocity, it is assigned a score - from 0 to 10, with asteroids scored 0 points are not likely to impact with the Earth and asteroids scored 10 points, will cause catastrophic destruction of the vast areas of the planet.
Asteroid 2011 MD, according to NASA, scored 0 points. Thus, according to representatives of NASA, the probability of impact is virtually zero (the exact probability of impact is estimated at 0.0066).
But the danger of this asteroid is still there, primarily for satellites. Also, some scientists warn, that such small asteroids before reaching the Earth's surface would disintegrate in the atmosphere, possibly with an explosion, such as air explosions can cause false inclusion of warning systems for nuclear attacks in nuclear countries.
So in 1996 the Parliamentary Assembly of the Council of Europe adopted a resolution indicating about the real danger to Earth from asteroids and comets, which called on all governments to support European research. On the basis of this resolution was created International Association "Space Guard", whose main goal is to provide service monitoring and tracking asteroids and comets, that approach to Earth.
In the U.S., monitoring the asteroid passes through several programs, of particular note LINEAR (Lincoln Near-Earth Asteroid Research), implemented by experts in the Lincoln Laboratory Sokkoro (New Mexico), with the assistance of the U.S. Air Force and NEAT (Near Earth Asteroid Tracking).