Bull’s-eye: NASA's DART craft successfully changed the orbit of the asteroid Dimorphos by colliding into the rocky body two weeks ago, according to the space agency.
The test shows humanity has the capability to stop an asteroid from hitting the planet, NASA administrator Bill Nelson said in a Tuesday press conference. “If an Earth-threatening asteroid was discovered, and we can see it far enough away, this technique could be used to deflect it,” he added.
The DART (Double Asteroid Redirection Test) was a spacecraft about the size of a refrigerator. When it collided with Dimorphos on September 26th, it was traveling at 14,000 miles per hour, which caused a noticeable impact that telescopes and radar images were able to capture.
Prior to the collision, the Dimorphos asteroid took 11 hours and 55 minutes to orbit its larger parent asteroid, Didymos, which is currently traveling around the Sun. Since then, astronomers across the Earth have been tracking the Dimorphos asteroid's orbit to see what’s changed.
“Now the team has confirmed the (DART) spacecraft’s impact altered Dimorphos' orbit around Didymos by 32 minutes, and therefore successfully moved its trajectory” Nelson said. “In other words, DART shortened the 11 hour and 55 minute orbit to 11 hours and 23 minutes. And it moved it in another location.”
Nelson added NASA would have considered the DART mission a success if it had slowed the asteroid’s orbit by only about ten minutes. Instead, the craft was able to slow the orbit by three times that amount.
“This is a watershed moment for planetary defense, and a watershed moment for humanity,” Nelson said.