Several ways of avoiding an asteroid impact have been described. Nonetheless, in March 2019, scientists reported that asteroids may be much more difficult to destroy than thought earlier. In addition, an asteroid may reassemble itself due to gravity after being disrupted.

Does NASA have a plan for an asteroid?

NASA will launch a spacecraft next month to hit an asteroid — on purpose — to change its path, testing for the first time a method of “planetary defense,” the agency announced Tuesday. The launch of the Double Asteroid Redirection Test (DART) mission will occur at 1:20 a.m. Eastern time on Nov. 24, NASA said.

How big is the asteroid that's coming in 2021?

According to data from NASA's Center for Near-Earth Object Studies, the asteroid 2021 SM3, which was discovered just last month, will pass by our planet on Friday. The diameter of the asteroid is up to 525 feet, just bigger than the 482-foot long Great Pyramid of Giza.