Despite the Hollywood doomsday scenarios, the odds of an asteroid hitting Earth and doing major damage anytime soon are slim, experts say. But scientists want to be prepared—just in case. In November, NASA launched a refrigerator-sized spacecraft that will slam into a small asteroid called Dimorphos at 15,000 miles per hour this fall. Scientists will then measure how the asteroid’s trajectory changes. Dimorphos doesn’t pose a threat to Earth; the idea is just to test whether the technique works. If successful, the mission—known as DART, or the Double Asteroid Redirection Test—could give NASA a confirmed weapon for its planetary-defense arsenal. And no matter what happens, researchers are excited about this historic experiment. “It’s kind of a big milestone for our species,” says Brent Barbee, a member of the team. “Like, the dinosaurs* didn’t have a DART mission.”


* Dinosaurs became extinct after an asteroid strike.