Asteroids are rocky objects orbiting the Sun and most of them are found orbiting in the Asteroid Belt between the orbits of Mars and Jupiter. If asteroids hit the Earth, it leads to mass extinction. A similar such case occurred 66 million years ago combining with an impact large meteorite leading to the demise of the dinosaurs. Astronomers track asteroids using telescopes developed with artificial intelligence.
More than 17000 asteroids were tracked between 2013 and 2016 at the Massachusetts Harvard-Smithsonian Centre for Astrophysics. Recently, they said that they are not able to track around 900 near-Earth asteroids that usually come at a distance of 48 million km of the orbit of Earth.
Also, 11 percent of the initially spotted ones were missing. According to astronomer Dr Veres. it is due to the delayed reporting of the reading of asteroid by telescopes. Sometimes, it could take 20 hours for reporting. The telescopes usually capture the coordinates of asteroids moving in space and follow them. Once, it is missed, it is difficult to chase it again as it may wander anywhere in the space.
Recently, it was announced by NASA's Jet Propulsion Laboratory that the asteroid 2010 WC9 having a size of about 60 to 120 metres will pass the Earth closer at about half the distance from the planet to the moon and a similar pass is expected next time in about 300 years.