Only 10% of asteroids that are likely to collide with the earth have yet been discovered

As a god of the Earth on September 8, 2014 Asteroid "2014 RCPassed, but as in 2014 RC, there were a lot of asteroids passing near the Earth, and I was told again that the possibility of a huge asteroid colliding with the Earth always needs attention . However, it seems that the discovery of asteroids that are at risk of colliding with the Earth does not progress as expected.

NASA is supposed to spot 90% of dangerous asteroids by 2020. It's at 10% - Vox
http://www.vox.com/2014/9/16/6226379/nasa-asteroid-risk-location

An asteroid with a diameter of 12 meters · 2014 RC passed through the distance of about 40,000 km from the earth around 3:18 am on September 8, 2014. Although it seems quite far apart when saying 40,000 km, considering that the distance from the earth to the moon is about 380,000 km, the 2014 RC which passed ten times as much as the moon when it is seen on the universe scale It can be said to be an asteroid passing close range.


Of the asteroids that are at risk of colliding with the Earth, about a huge one with a diameter of 10 km that seems to have collided with the earth 65 million years ago and caused extinction of the dinosaurs, 90% have been discovered, and fortunately it is known that none of them are on the trajectory where they can collide with the Earth. Since it is not possible to know exactly the total number of asteroids approaching the Earth, the number "90%" can be reasonably determined to be "sufficiently identifiable" in the mapping work of dangerous asteroids It is said to be numbers.


However, unlike a huge asteroid, specific work is delayed for medium size asteroids about several hundred meters in diameter. In addition, in 1908 collided with Siberia (Tungusuka explosion) It is estimated that the amount of energy the asteroid of 30 meters to 60 meters in diameter gave to Earth is more than 1000 times the atomic bomb dropped in Hiroshima.

As the existence of such asteroids at risk of collision with the Earth is gradually recognized, the budget for the project of the National Aeronautics and Space Administration (NASA) to discover asteroids closest to the Earth is 2009 NASA has been increasing from 4 million dollars (about 430 million yen) to 40 million dollars (about 4.3 billion yen) since the year, and now NASA not only installs a telescope on the earth to discover asteroids, A telescope capable of observing asteroids in space "NEOCamWe are also planning to launch.


However, NASA'sRecent report (PDF file attention)According to the present, only about 10% of medium size asteroids are grasped so far, and the necessity of proceeding with that specific work in a hurry has been clarified. In addition, NASA is aiming to discover 90% of medium size asteroids by 2020.


If an asteroid with a high possibility of colliding with the Earth is found, an "asteroid intercept plan" is brought up that strikes nuclear missiles on asteroids in space and avoids collision with the Earth by changing the trajectory, and this plan , The United Nations advocates the necessity of cooperation of each country, but the allocation of expenses estimated to cost 2.5 billion dollars (about 270 billion yen) is a bottleneck and the plan has not advanced.