NASA's Double Asteroid Redirection Test (DART) was Earth's first attempt at launching a spacecraft to intentionally collide with and deflect an asteroid as a planetary defense technique. On September 26, 2022, the DART spacecraft collided with a small asteroid moon called Dimorphos, which orbits a larger asteroid called Didymos. Neither asteroid posed a threat to Earth, but they represented similar celestial bodies that could one day approach and endanger the planet.