To preserve the planet in the near future, NASA has developed a method to divert two asteroids whose trajectory would encounter the Earth. A kinetic impactor with a weight of 300 kg will be propelled in the current space 2020. It will indeed join a couple of asteroids, namely Didymos A and its moon : Didymoon. The first is 800 meters in diameter, and the second 170 meters. DART (the name of the human satellite) will then hit Didymoon at a speed of 6 km per second. The goal is to deviate this moon from its orbit.
This method would cost 200 million euros, which is supposed to be too expensive; An alternative method is therefore being studied.