After ten months in space, NASA’s Double Asteroid Redirection Test (DART) – the world’s first planetary defense technology demonstration – successfully impacted its asteroid target on Monday, the agency’s first attempt to move an asteroid in space.
At 7:14 p.m. EDT, mission control at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, announced the successful impact.
DART’s collision with the asteroid Dimorphos, as part of NASA’s overall planetary defense strategy, demonstrates a viable mitigation technique for protecting the planet from an Earth-bound asteroid or comet, if one were discovered.
“At its core, DART represents an unprecedented success for planetary defense, but it is also a mission of unity with a real benefit for all humanity,” said NASA Administrator Bill Nelson. “As NASA studies the cosmos and our home planet, we’re also working to protect that home, and this international collaboration turned science fiction into science fact, demonstrating one way to protect Earth.”
DART was aiming for the asteroid moonlet Dimorphos, a small body measuring only 530 feet (160 meters) in diameter. It orbits Didymos, a larger, 2,560-foot (780-meter) asteroid. Neither asteroid is dangerous to Earth.
The one-way mission demonstrated that NASA can successfully navigate a spacecraft to intentionally collide with an asteroid in order to deflect it, a technique known as kinetic impact.
The investigation team will now use ground-based telescopes to confirm that DART’s impact altered Dimorphos’ orbit around Didymos. The impact is expected to shorten Dimorphos’ orbit by about 1%, or about 10 minutes; one of the primary goals of the full-scale test is to precisely measure how much the asteroid was deflected.
“Planetary Defense is a globally unifying effort that affects everyone living on Earth,” said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. “Now we know we can aim a spacecraft with the precision needed to impact even a small body in space. Just a small change in its speed is all we need to make a significant difference in the path an asteroid travels.”
The Didymos Reconnaissance and Asteroid Camera for Optical Navigation (DRACO), along with a sophisticated guidance, navigation, and control system that works in tandem with Small-body Maneuvering Autonomous Real Time Navigation (SMART Nav) algorithms, enabled DART to identify and distinguish between the two asteroids, targeting the smaller body.
These systems guided the 1,260-pound (570-kilogram) box-shaped spacecraft through the final 56,000 miles (90,000 kilometers) of space before crashing into Dimorphos at roughly 14,000 miles (22,530 kilometers) per hour to slightly slow the asteroid’s orbital speed. DRACO’s final images, captured seconds before impact, revealed the surface of Dimorphos in great detail.
“DART’s success provides a significant addition to the essential toolbox we must have to protect Earth from a devastating impact by an asteroid,” said Lindley Johnson, NASA’s Planetary Defense Officer. “This demonstrates we are no longer powerless to prevent this type of natural disaster. Coupled with enhanced capabilities to accelerate finding the remaining hazardous asteroid population by our next Planetary Defense mission, the Near-Earth Object (NEO) Surveyor, a DART successor could provide what we need to save the day.”
“This first-of-its-kind mission required incredible preparation and precision, and the team exceeded expectations on all counts,” said APL Director Ralph Semmel. “Beyond the truly exciting success of the technology demonstration, capabilities based on DART could one day be used to change the course of an asteroid to protect our planet and preserve life on Earth as we know it.”