How NASA shifted an asteroid's orbit

NASA's DART spacecraft struck the small asteroid Dimorphos in 2022, shortening its orbit around the larger asteroid Didymos and producing a measurable, very small change in the pair's 770‑day orbit around the Sun.

NASA's DART mission intentionally impacted the small asteroid Dimorphos in September 2022 as a test of whether a spacecraft could change an asteroid's path. The collision sped up Dimorphos's orbit around its larger companion, Didymos. Subsequent observations found a tiny change in the pair's orbit around the Sun. The results are being discussed as evidence about how kinetic impact might be used alongside detection efforts to address asteroid hazards. Key observations: - DART intentionally struck Dimorphos in September 2022 as a demonstration of kinetic impact as a deflection method. - Dimorphos's orbit around Didymos became about 33 minutes shorter after the impact. - Measurements show the binary pair's 770‑day orbital period around the Sun changed by a fraction of a second, reported as roughly 150 milliseconds per orbit. - The impact ejected a large cloud of debris, and that expelled material carried momentum away from Dimorphos, roughly doubling the effect of the spacecraft impact alone. - Because Dimorphos and Didymos are a binary system, a measurable change to one object affected the motion of the other. - Officials said Didymos was never on a path toward Earth and the DART experiment could not have placed it on one; NASA is also developing the Near‑Earth Object Surveyor to improve detection of hard‑to‑see asteroids. Summary: The observations show a kinetic impact produced both an immediate orbital change for Dimorphos around Didymos and a very small change in the pair's orbit around the Sun. The study is described as evidence that kinetic impact can alter an asteroid's motion, and agencies continue work on detection capabilities such as the Near‑Earth Object Surveyor as part of broader planning.