NASA confirmed that its Dart planetary defense mission successfully diverted an asteroid it collided with two weeks ago.
The Double Asteroid Redirection Test – Dart – was a proof of concept intended to test whether NASA could effectively move an Earth-threatening asteroid before it reached the planet. The agency slammed a refrigerator-sized spacecraft into the asteroid Dimorphos on September 22.
The impact changed the asteroid’s orbit around its parent asteroid, Didymos, shortening its orbit by approximately 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.
Dr Nancy Chabot of the Johns Hopkins University Applied Physics Laboratory, who led the NASA mission, said: “This is a 4% change in the orbital period of Dimorphos around Didymos. Dart only took a little hit. But if you wanted to do it in the future, you’d want to do it years in advance.
“Warning time is really 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 a collision course with Earth, that with enough advance warning, 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 said the Dart mission launched just before Thanksgiving last year and the spacecraft traveled for 10 months and 7 million miles (11.3 million kilometers) to hit the asteroid.
NASA officials celebrated on Sept. 22 when final photos from the spacecraft showed the spacecraft closing in on 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 realized it had successfully hit the rock.
Since the impact, astronomers have confirmed that the asteroid’s orbit has changed. Images released by Nasa showed ejecta being ejected from the asteroid in a long tail, indicating that something had hit it and broken up the rocks on its surface.
NASA Planetary Science Division Director Dr. Lori Glaze said during the press conference that the agency will continue to focus on planetary defense. These efforts will focus on developing the capability for long-range reconnaissance missions to examine asteroids that pose potential threats and to develop early warning systems.
“Time is the most important factor in being able to implement any defense technique,” he said.
NASA worked with the Italian Space Agency on the Dart mission project and Dr Glaze said international cooperation was a key factor in planetary defense as it was “not just an American concern”.
According to Dr. Glaze, one of the agency’s next missions is to establish a near-Earth orbital surveyor to scan the space around the planet for objects of interest or potential threats.