For the first time ever, NASA will attempt to modify the orbit of an asteroid - and you can watch it all live.
Teams on NASA's Double Asteroid Redirection Test, or DART, will target a small asteroid called Dimorphos.
The plan is to use DART to smash head-first into the asteroid, with the hope that it will slow down and avoid a collision with a larger asteroid.
There is apparently no threat to earth from either asteroid, or the planned collision.