NASA's DART mission didn't just change the orbit of asteroid it hit
NASA's DART mission didn't just change the orbit of asteroid it hit
Eric Lagatta, USA TODAYTue, March 10, 2026 at 11:48 AM UTC
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If an asteroid ever needs to be diverted from a collision course with Earth, a future planetary defense mission may resemble a test NASA pulled off four years ago.
In 2022, NASA's DART mission proved that potentially dangerous asteroids can be redirected from a trajectory toward Earth. Now, further observations of the aftermath of the mission – which entailed intentionally slamming a vehicle into a space rock – is revealing something unexpected in the binary system of asteroids.
NASA's mission didn’t just change the orbit of Dimorphos, the asteroid it hit, around its larger companion. The crash even shifted the orbit around the sun of Didymos, the larger of the two asteroids located within 7 million miles of Earth.
Because Didymos and Dimorphos are so intricately linked together by gravity, changes to one asteroid's orbit is destined to influence the other's, NASA said in a March press release. And over time, even a small change in an asteroid’s motion could be the difference between a hazardous object hitting our planet or missing it entirely, according to researchers.
"That change marks the first time a human-made object has measurably altered the path of a celestial body around the sun," NASA said in a statement.
1 / 02025 was a year of cosmic discoveries. Here's a look back at 6NASA’s Hubble Space Telescope last observed come 3I/ATLAS on Nov. 30, about four months after Hubble's first look at the interstellar comet. 3I/ATLAS became one of the biggest cosmic stories of the year when astronomers deemed it to be the third-ever discovered interstellar object in our solar system originating from an entirely different part of the galaxy.
Here's everything to know about NASA's DART mission, and what researchers continue to learn about how it altered the orbits of Didymos and Dimorphos.
What are Didymos and Dimorphos?
Didymos and Dismorphos are binary asteroids, meaning the smaller of them orbits the other. At just 530 feet in diameter, Dimorphos is a moonlet asteroid that orbits the larger 2,560-foot Didymos.
The space rocks are classified by NASA as near-Earth asteroids because their orbits bring them within 30 million miles of Earth’s own.
What was NASA's DART mission?
NASA's Double Asteroid Redirection Test (DART) spacecraft prior to impact at the Didymos binary asteroid system showed in this illustration handout.
In September 2022, NASA demonstrated that it was possible to nudge an incoming asteroid out of harm's way by slamming a spacecraft into Dimorphos as part of its Double Asteroid Redirection Test, or DART.
Launched in November 2021, DART traveled for more than 10 months before crashing into the asteroid at roughly 14,000 mph, blasting a huge cloud of rocky debris into space and altering the shape of the asteroid. Though the tiny asteroid posed no threat to Earth, NASA had set out to test a method of deflecting and changing the path of threatening objects hurtling toward Earth.
DART mission changed orbit of Didymos around sun
While Didymos was not the target in the collision, new research has revealed that the DART mission still altered the space rock's orbit around the sun.
Detailed in a study published March 6 in the journal Science Advances, observations of the pair’s motion revealed the asteroids' 770-day orbit around the sun changed by a mere fraction of a second following the DART mission. Using radar and other ground-based observations of the asteroid, researchers measured the asteroid’s speed, shape and position between October 2022 and March 2025 to reach their conclusion.
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“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 in Washington, said in a statement.
Previous research further concluded that the smaller asteroid Dimorphos' 12-hour orbit around the nearly half-mile-wide Didymos shortened by 33 minutes after the DART mission.
1 / 02025 spaceflight in photos. See images of Blue Origin, SpaceX missionsFirefly's Blue Ghost lunar lander captures its shadow on the moon's surface after completing a successful landing March 2 near a volcanic feature on the moon called Mons Latreille. The vehicle became the first of two landers manufactured by a U.S. company to reach the moon is 2025 in crucial missions to lay the groundwork for NASA to return humans to the lunar surface in the years ahead.DART spacecraft got photos of binary asteroids before impact
Before crashing into Dimorphos, the DART spacecraft was able to take images of the two celestial bodies that allowed researchers to examine the largest boulders on Didymos and Dimorphos to determine their geological features and origins.
View of Didymos, Dimorphos, and the plume coming off of Dimorphos after the Double Asteroid Redirect Test, or DART mission, purposefully made impact. This image shows DART's closest approach to the Dimorphos asteroid on Sept. 26, 2022.
Primarily, an analysis of the craters and surface strength on Didymos indicated it formed about 12.5 million years ago, while its smaller companion, Dimorphos, formed about 300,000 years ago. By studying the asteroids' respective surfaces, researchers were able to determine that the rocky Dimorphos likely formed from material loosed from the larger and smoother Didymos in a "large mass shedding event."
European spacecraft bound for Dimorphos
A view of the The Hera spacecraft in April in a cleanroom of the European Space Research and Technology Center (ESTEC) in Noordwijk, Netherlands. The spacecraft will investigate the deflection of asteroids as part of a planetary defense mission called Hera.
What's more, as of October 2024, a spacecraft from the European Space Agency is on the way to get an upclose look at Dimorphos' remnants.
Hera launched Oct. 7 from the Cape Canaveral Space Force Station in Florida on a two-year journey to what's left of the tiny moonlet asteroid.
The spacecraft is expected to enter the Didymos binary system's orbit in October 2026, when it will determine just how effective NASA's test was, according to the agency. Officials hope that by analyzing the results of NASA's experiment, space agencies will be better positioned to repeat the maneuver.
Is NASA prepared for asteroids that could hit Earth?
Should any asteroids ever do pose a serious threat to Earth, NASA and the world's space agencies have for years begun to build a planetary defense against dangerous space rocks.
For instance, the U.S. space agency's Planetary Defense Coordination Office was established in 2016 to catalog near-Earth objects that could crash into the planet.
NASA is also working on an asteroid-hunting telescope known as the NEO Surveyor to find near-Earth objects capable of causing significant damage. Set to launch no earlier than September 2027, the telescope is designed to discover 90% of asteroids and comets that are 460 feet in size or larger and come within 30 million miles of Earth’s orbit.
Eric Lagatta is the Space Connect reporter for the USA TODAY Network. Reach him at elagatta@usatodayco.com
This article originally appeared on USA TODAY: NASA's DART mission changed asteroid Didymos' orbit around sun
Source: “AOL Breaking”
