The DART (Double Asteroid Redirection Test) mission it was a proof of concept intended to test whether or not NASA would succeed in moving an Earth-threatening asteroid before it reaches the planet. The agency crashed a refrigerator-sized spacecraft into asteroid Dimorphos on September 22.
The impact changed the asteroid’s orbit around its parent asteroid, Didymos, and shortened its orbit by about 32 minutes. NASA Administrator Bill Nelson said in a news release Tuesday that the agency would have considered a 10-minute orbit change a success, suggesting the test exceeded expectations.
“This is a 4 percent change in the orbital period of Dimorphos around Didymos. DART just gave him a little push. But if you wanted to do this in the future, you would have to do it years in advance,” explained Dr. Nancy Chabot of the Johns Hopkins University Applied Physics Laboratory, who led the NASA mission. “Warning timing is pretty key here to allow this type of asteroid deflection to be used in the future as part of a much larger planetary defense strategy.”
Nelson confirmed that if an asteroid was on course to crash into Earth early enough, the agency could use the tactic to change its direction.
“I think NASA has shown that we are serious about being defenders of the planet,” he said.
The NASA administrator confirmed that the DART mission launched just before Thanksgiving last year. The DART spacecraft traveled 10 months and 7 million miles (11 million km) to hit the asteroid.
NASA officials celebrated on September 22 when final photos from the spacecraft showed it getting ever closer to the asteroid’s surface. When the spacecraft stopped sending back photos moments after showing an extreme close-up of the asteroid’s surface, agency officials determined that it had managed to hit the rock.
After the impact, astronomers confirmed that the asteroid’s orbit changed. Images NASA released showed the asteroid ejecting in a long tail, indicating that something hit it and shattered the rocks on its surface.
Director of NASA’s Science Mission Directorate, Planetary Sciences Division, Dr. Lori Glaze, noted during the press conference that the agency will continue to focus on planetary defense. Those efforts will focus on developing the capacity for long-range exploration missions to examine asteroids that pose potential threats and to develop early warning systems.
“Time is the single most important factor in being able to implement any defense technique,” said Dr. Glaze.
According to Dr. Glaze, one of the agency’s upcoming missions is to establish a near-Earth orbital rover to scan the space around Earth for potential objects, interests or threats.
NASA worked with the Italian Space Agency on the project. Dr. Glaze stressed that international cooperation is a key factor in planetary defense, since “it is not just an American concern.”