NASA’s straight-out-of-a-sci-fi-flick mission to alter the trajectory of an asteroid by smashing a rocket into it really did work.
On Tuesday, Oct. 11, NASA shared some data from its recent Double Asteroid Redirection Test (DART), showing that the orbit of the asteroid Dimorphos was successfully altered after a spacecraft purposely crashed into it a couple of weeks ago. The agency noted that this was not only the first successful test of asteroid deflection technology but the first time in history that humans had successfully altered the motion of a celestial object.
While Dimorphos didn’t pose any Armageddon-style threat, it did make for a good test subject as it was orbiting a larger parent asteroid (called Didymos). The DART spacecraft made an impact with Dimorphos on Sept. 26, and in the weeks since, astronomers have been measuring how long it’s taken Dimorphos to orbit Didymos. Pre-crash, that cycle took about 11 hours and 55 minutes, but post-crash, that orbit time has dropped to 11 hours and 23 minutes (plus or minus a two-minute margin of uncertainty).
The approximately 32-minute change was well above the minimum 73-second benchmark NASA had originally set out to mark success.
“All of us have a responsibility to protect our home planet. After all, it’s the only one we have,” NASA Administrator Bill Nelson said in a statement. “This mission shows that NASA is trying to be ready for whatever the universe throws at us. NASA has proven we are serious as a defender of the planet. This is a watershed moment for planetary defense and all of humanity, demonstrating commitment from NASA’s exceptional team and partners from around the world.”
While the change-in-orbit time data marked DART a success, scientists still have a lot more to dig into, like the “efficiency of momentum transfer” from the spacecraft’s collision with the asteroid. Astronomers will also be further analyzing the “many tons” of rock blown off Dimorphos and shot into space after the crash. (Obviously, the last thing humanity would want is to blow up one asteroid heading towards us, only for a slightly smaller chunk of it to destroy us all instead.)
“This result is one important step toward understanding the full effect of DART’s impact with its target asteroid,” Lori Glaze, director of NASA’s Planetary Science Division, said. “As new data come in each day, astronomers will be able to better assess whether, and how, a mission like DART could be used in the future to help protect Earth from a collision with an asteroid if we ever discover one headed our way.”