NASA's Double Asteroid Redirection Test mission successfully impacted the asteroid moonlet Dimorphos to change its orbit around the larger asteroid Didymos [1].

This achievement proves that humanity possesses the technical capability to redirect a celestial body. If a dangerous asteroid were discovered on a collision course with Earth, this "kinetic impactor" method could potentially prevent a global catastrophe.

The mission occurred in September 2022 [2], with the actual impact taking place on Sept. 26, 2022 [1]. The DART spacecraft was intentionally crashed into Dimorphos, which is a moonlet of the near-Earth asteroid Didymos [1]. At the time of the collision, the target was located approximately 11 million kilometers from Earth [1].

NASA designed the test to evaluate planetary-defense technology [1]. By ramming the asteroid at high speed, the agency sought to demonstrate that a spacecraft could alter a celestial object's trajectory [2]. This shift in orbit is a critical component of a strategy to move an asteroid away from a potential impact point with Earth [3].

Data from the mission confirmed that the impact was hard enough to shift the trajectory of the moonlet [2]. The redirection of Dimorphos serves as a proof of concept for future missions that may be required to safeguard the planet from asteroid threats [3].

The DART mission represents the first time a spacecraft has been used to intentionally change the motion of a celestial body [4]. The results provide a baseline for calculating how much mass and velocity are required to move different types of asteroids in space [1].

“NASA's DART mission successfully impacted the asteroid moonlet Dimorphos to change its orbit.”

The success of the DART mission transitions planetary defense from theoretical modeling to a proven operational capability. By confirming that kinetic impact can reliably alter an asteroid's path, space agencies now have a viable mechanism to mitigate the risk of large-scale impacts, provided that threats are detected early enough to allow for mission deployment.