DART

DART — the Double Asteroid Redirection Test — launched on November 24, 2021, with a mission profile unlike any before: deliberately crash into an asteroid and see if the impact could change its path. Its target was Dimorphos, a 530-foot moonlet orbiting the larger asteroid Didymos, chosen because the pair posed no threat to Earth and the effect could be precisely measured.

On September 26, 2022, DART slammed into Dimorphos at 14,000 mph, its camera streaming boulders growing larger until the feed cut to black. The impact shortened the moonlet’s orbit by 32 minutes — more than 25 times the success threshold — and the recoil of ejected debris multiplied the push. For the first time, humanity demonstrated it could alter the motion of a celestial body.