NASA’s DART Mission Shifts Asteroid’s Orbit Around the Sun
In a landmark achievement for planetary defense, NASA’s Double Asteroid Redirection Test (DART) mission has successfully altered the orbit of the asteroid Didymos around the Sun. This marks the first time a human-made object has measurably changed the path of a celestial body’s orbit, demonstrating a potential method for mitigating future asteroid impact risks.
The DART spacecraft intentionally collided with Dimorphos, a moonlet orbiting Didymos, on September 26, 2022. The impact, captured by the Italian Space Agency’s LICIACube, sent rocky debris fanning out from the smaller asteroid. Novel research, published on March 6, 2026, details how the collision not only changed Dimorphos’s motion around Didymos, but also subtly shifted the orbit of both asteroids around the Sun.
According to the study published in Science Advances, the 770-day orbital period of the pair around the Sun changed by a fraction of a second following the impact. This change, while tiny, is significant as it confirms the feasibility of using kinetic impact as a method of asteroid deflection. The DART mission was designed to assess how much a spacecraft impact deflects an asteroid through momentum transfer.
The Didymos-Dimorphos system was chosen as an ideal target for the test because neither asteroid poses a threat to Earth. Dimorphos is approximately 525 feet (160 meters) in width. Observations from the Hubble Space Telescope revealed tails of dust ejected from the asteroid system in the days following the impact.
The DART spacecraft, launched on November 24, 2021, traveled approximately 6.8 million miles (10.9 million kilometers) before impacting Dimorphos at a speed of 14,000 mph (23,000 km/h). The collision shortened Dimorphos’s orbit around Didymos by 32 minutes, exceeding the pre-defined success threshold of 73 seconds, as detailed on Wikipedia’s page on the Double Asteroid Redirection Test. This successful test provides valuable data for future planetary defense strategies.
The mission involved several key components, including the DART impactor itself, the LICIACube CubeSat, and instruments like the Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO). The Smithsonian Magazine reports that the spacecraft was roughly the size of a small car.
