What could we do if we spotted a dangerous asteroid on a collision course with our planet? NASA has an idea that it’s testing out, though it might sound like a Hollywood plot. The DART mission will deliberately fly a small spacecraft into an asteroid to see whether its path can be deflected. The idea is to test whether this concept would be effective if a real dangerous asteroid was observed heading toward Earth.
The asteroid Dimorphos is one of a binary pair, along with its larger companion Didymos. They orbit the sun in around two years, in an eccentric orbit which at some points comes as close to the sun as Earth is, and at other points is 2.3 times this distance from the sun. The DART researchers needed to confirm the asteroids’ exact orbit to make sure the spacecraft would intercept them correctly, which they did by using observations in early 2021.
“The before-and-after nature of this experiment requires exquisite knowledge of the asteroid system before we do anything to it,” explained Nick Moskovitz, an astronomer with Lowell Observatory who worked on the observation campaign, in a statement. “We don’t want to, at the last minute, say, ‘Oh, here’s something we hadn’t thought about or phenomena we hadn’t considered.’ We want to be sure that any change we see is entirely due to what DART did.