Here's How Many Years in Advance We'd Need to Stop a Killer Asteroid Coming For Earth MORGAN MCFALL-JOHNSEN & AYLIN WOODWARD, BUSINESS INSIDER 13 MAY 2021 Last month, experts from NASA and other space agencies around the world faced a troubling hypothetical scenario: A mysterious asteroid had just been discovered 35 million miles away, and it was heading for Earth. The space rock was expected to hit in six months.
The situation was fictional, part of a week-long exercise that simulated an incoming asteroid in order to help US and international experts practice how to respond to such a situation. The simulation taught the group a difficult lesson: If an Earth-bound asteroid were spotted with that little warning, there's nothing anyone could do to keep it from hitting the planet.