Humans learn to down asteroids

Japanese researchers have conducted successful tests of a special device that will help spacecraft Hayabusa-2 to obtain samples from the interior of an asteroid. The device is a "cannon" shooting solid metal shells. According to experts, the obtained findings will shed light on the formation of such objects as asteroids.

The asteroid "cannon" so far does not have analogues in the world. It is capable of hitting a target from a distance of 100 meters. As a result, an artificial crater is formed on the surface of the asteroid, and a sample of rock can be taken from it to determine the composition of the celestial body.

One of the main tasks of the device is to achieve maximum accuracy. The device has shown excellent results during the tests. Specialists of the Japan Aerospace Exploration Agency commented that a shell hit right on target at expected speed.

Why are scientists so concerned about asteroids? This is because they represent a potential threat to the Earth. Over 98 percent of all asteroids in the Solar System are concentrated in the main asteroid belt located between the orbits of Mars and Jupiter as well as the Kuiper belt and theoretically in the Oort cloud. Periodically, some of them as a result of collisions with neighbors or under the influence of gravity from larger objects descend from their orbits and sometimes move towards Earth.

Scientists consider all asteroids capable of approaching the Earth at a distance less than or equal to 0.05 AU and the absolute magnitude of less than 22 to be potentially hazardous objects. With the average albedo of 0.13, the diameter of the asteroid should be about 150 meters.

Asteroid danger is often evaluated according to the so-called Turin scale. Depending on orbital velocity and mass, potentially hazardous objects are assigned a certain number of points from 0 to 10. The bodies assigned a score of 0 points on Turin scale do not have a chance of coming into contact with the Earth, and those with a score of 10 points may cause a planetary catastrophe.

Recently researchers of the Crimean Observatory reported the discovery of 410 -meter asteroid whose probability of collision with our planet in 2032, according to NASA, is 1/ 14,000. Shortly after, the head of Roscosmos Oleg Ostapenko made ​​a statement that the Academy of Sciences in cooperation with the Russian Space Agency began a project aimed at diverting the asteroid hazard.

Hayabusa-2 was preceded by an automatic probe Hayabusa designed to fly to asteroid Itokawa and launched into space in May of 2003. The mission did not go smoothly. Initially, the launch was scheduled for 2002 but was postponed. After the launch it got into the zone of a powerful solar flare that damaged one of the ion batteries. However, this did not prevent it from fulfilling its scientific program.

Although the lander MINERVA failed to separate from the probe, it still landed. For some unknown reason, special shells that were to "shoot" the soil did not fulfill its function. On the way back, Hayabusa also experienced a technical problem. It returned to Earth not in 2007 as planned, but three years later. In July of 2010 it was announced that a 40-centimeter capsule unit found over fifteen hundred dust microparticles with a diameter under fifty millionths of a meter. Presumably, it was an asteroid material. However, there is no certainty that this was the dust from Itokawa. The Japanese decided to repeat the mission in the hope that the second attempt will be more successful.

This time the goal is 914-meter asteroid 162173, formerly denoted as 1999 JU3. It is slightly larger than Itokawa. Furthermore, it has an almost perfect spherical shape, whereas Itokawa has an elongated shape. It may also affect the success of the mission.

Hayabusa - 2 will be dramatically improved over its predecessor. It will have updated ion engines, as well as navigation and control equipment. Hayabusa-2 will feature shells detonating from the surface of the body. As experts believe, the chances of getting soil samples will be much higher.
 
The launch of Hayabusa-2 is scheduled for December of 2014. In mid-2018 it will encounter the asteroid, obtain samples, and return to Earth in 2020.
 
Irina Shlionskaya

Pravda.Ru 

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