NASA made history last week by successfully striking an asteroid with an autonomous spacecraft as the world’s first planetary defense mission. While it was an exciting moment, it won’t be the last part of the mission.
The goal of the Double Asteroid Redirection Test, or DART, was to prove that NASA’s Planetary Defense Coordination Office (PDCO) can change the path of an asteroid using a kinetic impact.
They used an autonomous spacecraft with an instrument aboard — the Didymos Reconnaissance and Asteroid Camera for Optical Navigation, or DRACO — that guided it to its target, Dimorphos, with the help of Small-body Maneuvering Autonomous Real Time Navigation, or Smart Nav.
Dimorphos, a 530-foot moonlet asteroid, orbits the 2,560-foot diameter Didymos asteroid. While they’re both within 7 million miles of Earth, neither poses a threat to our planet. Their proximity to Earth, though, is important for what comes next for NASA and its partners: observation.
Specifically, researchers expect DART, which hit Dimorphos at about 14,000 miles per hour, to shorten the asteroid’s orbit by roughly 10 minutes, or 1%. According to NASA, researchers around the world are now using telescopes, both on the ground and in space, to observe the Dimorphos and Didymos.
Two of NASA’s most iconic telescopes — the Hubble Space Telescope and the recently-launched James Webb Space Telescope — were able to capture DART’s impact with Dimorphos. NASA shared photos captured by both last week. They can be seen below, beside a view from DART as it reached its target.
Hubble and Webb will continue observing Dimorphos and Didymos over the next several weeks.
Researchers will also be characterizing the particles ejected into space by DART’s impact, which appear as rays in the Hubble and Webb photos above, and measuring how Dimorphos’ orbit has changed to determine just how effective DART was.
Scientists won’t know the precise change until November.
Then, in four years, NASA says the European Space Agency’s Hera project will survey Dimorphos and Didymos. They will focus on the crater left by DART and Dimorphos’ mass. Scientists say it is possible the crater measures 10 to 20 meters.
Though there is still more to be reviewed surrounding DART’s impact, experts are calling it mission accomplished.
“As far as we can tell, our first planetary defense test was a success,” Mission Control’s Elena Adams told a news conference after the impact as the room filled with applause. “I think Earthlings should sleep better. Definitely, I will.”
The DART team will move on to other missions now, and the PDCO will continue its task of finding near-Earth objects, warning of their close approaches, coordinating an action plan, and mitigating any potential impacts.
The Associated Press contributed to this report.