NASA Study Finds DART Mission Impact Altered Orbit of Didymos–Dimorphos System Around the Sun

The DART spacecraft's intentional impact on the asteroid moonlet Dimorphos shifted the orbit of both Didymos and Dimorphos around the Sun.

Published on Mar. 8, 2026

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New research reveals that when NASA's DART (Double Asteroid Redirection Test) spacecraft intentionally impacted the asteroid moonlet Dimorphos in September 2022, it not only changed the motion of Dimorphos around its larger companion, Didymos, but also shifted the orbit of both asteroids around the Sun. Observations showed the 770-day orbital period around the Sun changed by a fraction of a second after the DART impact, marking the first time a human-made object has measurably altered the path of a celestial body around the Sun.

Why it matters

This change in the binary system's orbital speed, though tiny, underscores the role spacecraft could play in deflecting a potentially hazardous asteroid on a collision course with Earth. The key is detecting near-Earth objects far enough in advance to send a kinetic impactor like DART to alter their trajectory.

The details

When DART struck Dimorphos, the impact blasted a huge cloud of rocky debris into space, altering the shape of the 560-foot-wide asteroid. The debris carried its own momentum away from Dimorphos, giving it an explosive thrust that doubled the punch created by the spacecraft alone. Earlier research showed the smaller asteroid's 12-hour orbital period around the nearly half-mile-wide Didymos shortened by 33 minutes. The new study shows the impact ejected so much material from the binary system that it also changed the binary's orbital period around the Sun by 0.15 seconds.

  • DART intentionally impacted the asteroid moonlet Dimorphos in September 2022.
  • Researchers observed two tails of dust ejected from the Didymos-Dimorphos asteroid system several days after the DART impact.
  • The study was published on Friday, March 8, 2026, in the journal Science Advances.

The players

NASA

The U.S. National Aeronautics and Space Administration, the federal agency responsible for the civilian space program, aeronautics, and space research.

DART (Double Asteroid Redirection Test)

NASA's spacecraft that intentionally impacted the asteroid moonlet Dimorphos in September 2022, marking humanity's first mission to intentionally move a celestial object.

Didymos

The nearly half-mile-wide (805-meter-wide) asteroid that Dimorphos orbits in a binary system.

Dimorphos

The 560-foot-wide (170-meter-wide) asteroid moonlet that DART intentionally impacted.

Thomas Statler

The lead scientist for solar system small bodies at NASA Headquarters in Washington.

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What they’re saying

“This is a tiny change to the orbit, but given enough time, even a tiny change can grow to a significant deflection.”

— Thomas Statler, Lead scientist for solar system small bodies at NASA Headquarters (clarksvilleonline.com)

“The change in the binary system's orbital speed was about 11.7 microns per second, or 1.7 inches per hour. Over time, such a small change in an asteroid's motion can make the difference between a hazardous object hitting or missing our planet.”

— Rahil Makadia, Lead author of the study at the University of Illinois Urbana-Champaign (clarksvilleonline.com)

What’s next

NASA is building the Near-Earth Object (NEO) Surveyor mission, a next-generation space survey telescope that will seek out some of the hardest-to-find near-Earth objects, such as dark asteroids and comets, to help detect potentially hazardous objects far enough in advance to send a kinetic impactor like DART to alter their trajectory.

The takeaway

The DART mission's impact on the Didymos-Dimorphos binary asteroid system has shown that even a small change in an asteroid's motion can make a significant difference in whether it hits or misses Earth, underscoring the importance of developing planetary defense capabilities to protect our planet from potential asteroid threats.