NASA plans the first planetary defense mission in history

According to NASA, DART's target is a 150-meter moonlet called Didymos B, a small satellite orbiting a larger near-Earth asteroid called Didymos. The asteroid binary is located roughly 11 million kilometers from Earth.

DART will crash against the moonlet at a speed of roughly 6 kilometers per second. Its objective is to change the speed and direction of the incoming object. The spacecraft is scheduled to launch in June 2021 and expected to hit the asteroid by October 2022.