By BlueShift | 2026-03-18

A NASA spacecraft that purposely smashed into the moonlet asteroid Dimorphos in 2022 pushed the space rock and its larger companion Didymos into a slightly different orbit around the Sun, per new research published March 6.

Previous research had shown that the US space agency's Double Asteroid Redirection Test (DART) spacecraft had pushed Dimorphos into a smaller, faster orbit around Didymos.

The DART test was designed to assess whether humanity could protect Earth from threatening space rocks. It was not based on an actual threat to Earth.

But the successful experiment and additional analysis offers a solid data point to mount a defense if any such eventual threat is detected, researchers said.

"This study marks a notable step forward in our ability to prevent future asteroid impacts on Earth," the team of international researchers wrote in a paper published in the journal Science Advances.

Their observations showed the DART test marked "the first time a human-made object has measurably altered the path of a celestial body around the Sun," NASA said in a statement.

The DART spacecraft was designed, built and operated by the Johns Hopkins Applied Physics Laboratory for NASA’s Planetary Defense Coordination Office, which oversees planetary defense efforts.

It was humanity’s first attempt to intentionally move a celestial object.

Earlier research showed the smaller asteroid’s 12-hour orbital period around 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.

"This is a tiny change to the orbit, but given enough time, even a tiny change can grow to a significant deflection," said Thomas Statler, lead scientist for solar system small bodies at NASA headquarters in Washington.

"The team’s amazingly precise measurement again validates kinetic impact as a technique for defending Earth against asteroid hazards and shows how a binary asteroid might be deflected by impacting just one member of the pair."

Tracking stellar occultations

The study's lead author Rahil Makadia told AFP his team tracked stellar occultations -- the moment when an asteroid passes in front of a star, causing a brief dimming for less than a second.

The team used this to obtain hyper-precise measurements of the asteroid's position, speed and shape, he said.

Measuring stellar occultations is challenging, according to NASA.

Astronomers have to be in the right place at the right time with several observing stations, sometimes miles apart, to track the predicted path of the asteroid in front of a specific star.

The team relied on volunteer astronomers around the globe who recorded 22 stellar occultations between October 2022 and March 2025.

Using that data along with years of additional observations, Makadia said the team was able to measure Didymos's orbit around the sun with precision.

"We were able to measure what this change was exactly," he said, and make computations that could assist with future "planetary defense efforts."

The DART test shows how spacecraft could assist, if a potentially hazardous asteroid is found to be on a collision course in the future.

According to NASA, the key is detecting near-Earth objects far enough in advance to send a "kinetic impactor."

NASA's Near-Earth Object (NEO) Surveyor mission -- a next-generation space survey telescope -- is the first to be built for planetary defense.

Managed by the agency's Jet Propulsion Laboratory, the mission will seek out some of the hardest-to-find near-Earth objects, such as dark asteroids and comets that do not reflect much visible light.