https://www.vice.com/en_us/article/k7bpxe/nasa-successfully-punched-an-asteroid-off-course-dart-test

Humanity has moved a celestial body for the first time, representatives of NASA’s Double Asteroid Redirection Test (DART), confirmed during a press briefing on Tuesday. 

The DART mission slammed a refrigerator-sized spacecraft into an asteroid two weeks ago in the first-ever test of a defense system against annihilation by asteroid. When DART crashed into Dimorphos, a small rock that orbits a larger asteroid called Didymos, it shortened its orbit by a whopping 32 minutes. In other words, DART changed the time it takes for Dimorphos, which measures about 500 feet across, to orbit the half-mile-wide Didymos from 11 hours and 55 minutes to 11 hours and 21 minutes.