NASA comes up with plan to defend Earth from asteroids

In February 2013, when the Chelyabinsk meteor exploded in Earth's atmosphere, it caused extensive damages and injuries, and in order to defend the Earth from asteroids in future, NASA has come up with a plan to spot the objects near Earth first. Amy Mainzer, principal investigator of NASA's asteroid-hunting mission, said that if an object is found only a few days from impact, it will greatly limit the options.