NASA planetary defense mission successfully disrupted asteroid's orbit

NASA successfully disrupted the orbit of an asteroid in a mission last month that tested a strategy to defend against a potential asteroid headed toward Earth, the agency said on Tuesday.

"This is a watershed moment for planetary defense and a watershed moment for humanity," NASA Administrator Bill Nelson said on Tuesday.

The Double Asteroid Redirection Test spacecraft, or DART, collided with an asteroid on Sept. 26 after traveling roughly 7 million miles to reach its point of impact.

On the receiving end of that collision was Dimorphos, a small asteroid that is the moon of a bigger space rock, Didymos.

NASA confirmed that the collision changed the trajectory of Dimorphos by comparing the length of its orbit before and after impact, Nelson said.

Before impact, it took Dimorphos 11 hours and 55 minutes to complete its orbit around Didymos. After impact, the orbit took 32 fewer minutes, Nelson said.

"It was expected to be huge success if it only slowed by 10 minutes," Nelson said. "It was a bull's eye."

At the moment of impact, the refrigerator-sized DART spacecraft was traveling at 13,000 mph, Nelson said.

Asteroid Dimorphos, which NASA said is the size of a football stadium, does not pose a threat to the planet, in this case. But the mission aimed to test technologies that could prevent a potentially catastrophic asteroid impact.

Dimorphos, which means "having two forms" in Greek, spans 525 feet or 160 meters in diameter.

The results from the mission show that this technique could be used to deflect a future asteroid headed toward Earth, Nelson said.

"All of us have a responsibility to protect our home planet," Nelson said. "After all, it's the only one we have."

"This mission shows that NASA is trying to be ready for whatever the universe throws at us," he said.

Giorgio Saccoccia, the president of the Italian Space Agency, a partner on the mission, celebrated its success.

"This is something we can really be proud of as an international endeavor," he said. "I think our planet can feel a bit more safe for the future."