The coming asteroid flight raises concerns about the threat of asteroid and comet falling to the ground. Our planet keeps several traces of such disasters. This includes the meteor crater in Arizona, which diameter is more than 150 km, two giant craters at Yucatán peninsula and in Sahara desert. If DA14 asteroid ever clashes with Earth it will cause a serious damage, Vladimir Surdin, assistant professor of the astronomy department of the physics faculty at the Moscow State University says.
"This asteroid is 45 meters big, which is approximately the same size as the size of the of Tunguska meteorite which fell to Earth 100 years ago. The explosion of the Tunguska meteorite caused huge environmental damage to taiga forests. The area of forest fires was comparable to the area of modern Moscow. The fall of a celestial body which is dozens of meters big is dangerous if it happens over a densely populated area. It can be even more disastrous if it falls into the sea causing tsunami that seriously damage coastal areas."
Astronomers detected DA14 asteroid a year ago. They calculated that on February 15 asteroid’s orbit won’t cross the orbit of Earth. But when it comes to 10 meter celestial bodies it makes things much more difficult because it is possible to detect them only one day before they reach Earth. In 2010 such an asteroid exploded above a deserted area in Indonesia and the blast was more powerful that the blast in Hiroshima. Scientists have started to create asteroid monitoring network, which will make it possible to detect dangerous falling objects two weeks before they hit Earth providing enough time for people evacuation from a dangerous area. Telescopes which are powerful enough to detect asteroids far from Earth do not exist but they are being built now, Vladimir Surdin says.
"At present several countries are joining efforts to build such telescopes and launch them to space. The problem is that we can’t detect the asteroids and comets flying to Earth from the side of the Sun because the Sun blinds optical equipment. That is why it is necessary to launch telescopes to space to the area behind the Sun bringing them to the orbit which is on the opposite side of Earth orbit."
It is planned to bring the first telescope Sentinel into space between the orbits of Earth and Venus in 2018. At present a US private fund is raising funds for the project. The telescope will use infra-red band detecting asteroids using temperature difference between the surface of asteroids and the cosmic background. Nevertheless even state-of-the-art instruments won’t remove threat of asteroid falling on Earth, Sergey Bogachev, senior researcher at the Institute of Physics of the Russian Academy of Sciences, says.
"Today scientists are working on different methods of control over the environment but such systems do not make it possible to prevent clashes of celestial objects with Earth. These are early warning systems but not prevention tools. So far humans can’t prevent such clashes."
As of today about twenty methods of fighting dangerous space objects have been invented. For example, in order to make an asteroid deviate from its Earth-targeted trajectory it is proposed to installing a rocket engine on its surface. It is also proposed to explode an asteroid at a safe distance from Earth . It is not excluded that scientists will have to apply one of the methods to DA14 asteroid, which orbit is now almost coincides with Earth orbit but its coordinates will significantly change when the asteroid closes our planet. The distance at which the asteroid passes Earth will define the probability of future clashes of celestial bodies with Earth. For the period till 2069 scientists estimate the risk as 1 chance of 3,000.