The DART Mission and Planetary Defense: A Crash Course

Asteroids have hit the Earth throughout its history, but humanity is developing the tools to help us avoid the fate of the dinosaurs. One technique that is being developed is the “kinetic impactor”, where a spacecraft is crashed into an object in order to change its course. The Double Asteroid Redirection Test (DART) is NASA’s first planetary defense test mission, designed to test this technique. DART launched in November, with arrival at its target this coming September. The target of the DART spacecraft is the moonlet Dimorphos, a 150-m moonlet orbiting the 780-m asteroid Dimorphos. By changing the orbit of Dimorphos around Didymos,  the results can be detected much more easily than changing the orbit of an asteroid around the Sun. Didymos and Dimorphos are not dangerous objects themselves, and DART will not bring them closer to Earth, making them excellent targets for this test. I will discuss the field of planetary defense, the plans for the DART mission, and other planetary defense efforts that are underway.