On September 26, 2022, a NASA spacecraft ran into the asteroid Dimorphos at nearly 15,000 miles per hour. Far from being a multi-million-dollar boondoggle, this collision is precisely what astronomers had planned. The spacecraft was part of the Double Asteroid Redirection Test mission, or DART for short. The goal: to test technology that could potentially divert a large asteroid, should we ever locate one on a collision course with Earth.