Fresh analysis shows that in 2022, NASA's deliberate impact of a probe on the asteroid satellite Dimorphos adjusted not only its path relative to the main asteroid Didymos but also the combined system's route around the Sun. A release from NASA's Jet Propulsion Laboratory describes this event as the debut case of artificial means detectably modifying a cosmic body's solar path. The outcome holds significant potential for advancing techniques to shield Earth from dangerous extraterrestrial threats.
The Double Asteroid Redirection Test, or DART, sought to prove a viable approach for steering away potentially harmful asteroids by striking the benign moonlet Dimorphos, roughly 560 feet across. NASA soon announced the operation's triumph following early evaluations that confirmed the targeted strike had reduced Dimorphos's cycle around Didymos, the bigger element in this dual-asteroid configuration. Researchers from JPL's 2024 follow-up report indicated the satellite's orbital span had shortened by around 33 minutes, shifting its track about 120 feet nearer to Didymos. Current research extends this to show the entire paired system experienced the change, extending beyond Dimorphos alone.
The Didymos-Dimorphos pair follows a 770-day loop around the Sun, now modified by roughly 11.7 microns per second, equivalent to 1.7 inches hourly, according to principal investigator Rahil Makadia. While the modification seems slight, Makadia points out that over extended durations, this minor velocity tweak could spell the difference between a threatening asteroid striking Earth or veering clear.