According to NASA, they have identified and tracked over 90 percent of the asteroids near the Earth (NEAs) with a minimum width of 1 km, which is big enough to be a threat to the humans if they line up with the Earth.
Asteroid close approach: On Wednesday, a huge asteroid will fly past the Earth, a report in Space indicated. According to some reports, the approach could pose a threat to the Earth, but ‘Space’, citing NASA scientists, has said that the asteroid is no danger. The asteroid, called 1998 OR2, will fly by the Earth within a distance of 63 lakh kilometers on Wednesday, the report said. Compared to the 90 billion light-year vastness of the universe, the fly past of the asteroid seems like a close shave, but the distance is enough for chances of any danger to the Earth to be zero, the report cited scientists as saying.
Putting this distance into context, even at its closest, the asteroid will be 16 times farther from the Earth than the Moon is, i.e., 3.85 lakh kilometers, the report stated.
The report further stated that in the foreseeable future, there are no big asteroids that scientists see as a threat. The report quoted Manager of NASA’s Centre for Near-Earth Object Studies Paul Chodas as saying that they don’t have any significantly-sized asteroid which has significant chances of hitting the Earth, on their list.
The report also stated that according to NASA, they have identified and tracked over 90 percent of the asteroids near the Earth (NEAs) with a minimum width of 1 km, which is big enough to be a threat to the humans if they line up with the Earth.
However, Chodas and NASA’s Planetary Defence Officer Lindley Johnson have both said that the fact that NASA does not have any asteroid on its list should not lead to complacency, since there are a large number of NEAs and some dangerous ones could go undetected. Moreover, the paths of the asteroids often get altered due to gravitational pulls of various spatial objects, making it difficult for scientists to accurately predict their orbits for a long time. The fact is attested by the end of the dinosaurs, which occurred due to asteroid collision.
Johnson was quoted by the report as saying that while such an impact is a rare event, it is inevitable. This inevitability is what makes discovery and tracking of asteroids important, Johnson and Chodas said. A discovery of such an incoming asteroid far in advance could allow us to do something about it, they said.
Some of the solutions that the scientists offered to deflect an asteroid collision if detected in advance include mounting a kinetic-impactor deflection mission, which would include sending a spacecraft to knock the asteroid off its path, if the asteroid is detected 5 to 10 years before possible collision. If the time available is considerably more than that, a non-violent gravity tractor method could help in changing the trajectory of the asteroid, while very little time available could mean having to use nuclear weapons to destroy the threat.