DART spacecraft slams into asteroid
The mission is a test to see if NASA could knock an Earth-bound asteroid off its path, should we ever need to.
llustration of NASA’s DART spacecraft and the Italian Space Agency’s LICIACube prior to impact at the Didymos binary system. Image Credit: NASA/Johns Hopkins APL/Steve Gribben
Tonight, around 6.8 million miles away from Earth, NASA slammed a spacecraft into an asteroid in a bid to change the rock’s trajectory. This is the agency’s first test of a technology designed to defend Earth against asteroids or comets that might one day threaten to collide with our planet.
“Humans: one, asteroids: zero!” declared NASA communications strategist Tahira Allen amid celebration and cheering at Johns Hopkins University's Applied Physics Laboratory, over a NASA livestream.
From “Armageddon” to “Don’t Look Up,” Hollywood has long imagined how scientists could redirect an asteroid headed toward Earth. With lower stakes, NASA is testing its own theory with the Double Asteroid Redirection Test (DART). The mission launched 10 months ago, carrying with it an autonomous guiding system called SMART Nav to help it maneuver and target an asteroid.
For the test, scientists chose Dimorphos, a 525-foot asteroid “moonlet” that circles a larger asteroid called Didymos. "We needed something with a moon that was small enough that we could move it with a strike from a spacecraft, but not so small that we would wreck the moon,” Andy Rivki, a scientist working on the DART mission said in a livestream leading up to the impact. (Neither Dimorphos nor Didymos poses any threat to Earth)
The spacecraft itself had a camera that transmitted its approach live. As it blazed toward Dimorphos at 4 miles per second, the asteroid grew from a tiny white dot in the video feed to a detailed view of gray rocks and rubble that filled the screen. And then: nothing.
“We’ve made impact!” DART mission members shouted as the room erupted into cheers.
“Now is when the science starts,” said Lori Glaze, director of NASA's planetary science division, after the impact. It will be days before scientists can calculate if, and by how much, the asteroid’s trajectory was altered. As Dimorphos circles around, telescopes on Earth can help capture variation in its orbit, and hence, the success of the mission.
In the next 100 years, a scenario like the one in “Armageddon” is highly unlikely. But DART may be proof that if Earth were to be threatened by an asteroid, humans could do something about it. “We are embarking on a new era of humankind, an era in which we potentially have the capability to protect ourself from something like a dangerous, hazardous asteroid impact,” Glaze said.
Correction: An earlier version of this article attributed quotes from Lori Glaze to Laurie Leshin.