IMPACT: NASA DART mission successfully collides with asteroid
NASA’s DART spacecraft collided with asteroid Dimorphos in order to demonstrate a planetary defense technology called kinetic impactor. This is a view of the asteroid just seconds before impact. Credit: NASA
For the first time, a NASA spacecraft was purposefully slammed into an asteroid in order to change the small body’s orbital period.
At 7:14 p.m. EDT (23:14 UTC) Sept. 26, 2022, NASA’s DART mission spacecraft collided with Dimorphos, a small moonlet orbiting a larger asteroid by the name of Didymos. It was humanity’s first attempt to move a celestial body and a test of a type of planetary defense technique called “kinetic impact.”
“At its core, DART represents an unprecedented success for planetary defense, but it is also a mission of unity with a real benefit for all humanity,” said NASA Administrator Bill Nelson. “As NASA studies the cosmos and our home planet, we’re also working to protect that home, and this international collaboration turned science fiction into science fact, demonstrating one way to protect Earth.”
An infographic explaining how DART’s impact will create a new orbit for Dimorphos around Didymos. Credit: NASA
‘Loss of signal confirmed: We have impact!’
The Double Asteroid Redirection Test — DART — mission, developed and led for NASA by the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, was engineered, launched and flown for the sole purpose of this evening’s destructive impact, facilitating an investigation into the feasibility of using kinetic impact as a means to deflect future potential threats to Earth.
DART was launched atop a Falcon 9 rocket on Nov. 24, 2021, to deliberately collide with a target asteroid — one which poses no threat to Earth — in order to change its speed and path. DART’s target was the binary, near-Earth asteroid system Didymos, composed of the roughly 2,560-foot (780-meter) diameter Didymos, and the smaller roughly 530-foot (160-meter) Dimorphos.
The 1,260-pound (570-kilogram) spacecraft impacted the small asteroid at a speed of some 4 miles (6.4 kilometers) per second.
Key to this evening’s impact being rated a success, DART needed to navigate itself in the relatively close quarters of Dimorphos, which required the design and use of the sole instrument aboard the spacecraft — the Didymos Reconnaissance and Asteroid Camera for Optical navigation, or DRACO.
DRACO was a resounding success, both providing very high resolution images just prior to impact, and ensuring that the target was hit as intended. The control room cheered with approximately 19 minutes remaining to impact, as ground controllers confirmed, “We have precision lock.”
Don't want to miss a thing? Watch the final moments from the #DARTMission on its collision course with asteroid Dimporphos. pic.twitter.com/2qbVMnqQrD
— NASA (@NASA) September 26, 2022
‘Now is when the science starts’
The DART Investigation Team will now be able to begin the observation and interpretation phase of the mission, by monitoring and comparing what its orbit looks like now, relative to what it was before.
Additional imagery is expected in the days to come via an Italian CubeSat that was released from the main DART spacecraft about 10 days before impact.
LICIACube — Light Italian CubeSat for Imaging of Asteroids — is a 31-pound (14-kilogram) spacecraft that is designed to record images of the ejecta plume created by DART’s impact.
Over the coming weeks and months, ground based telescopes will be analyzing the orbit of Dimorphos to see by how much the impact changed its speed around the larger Didymos. Before impact, the orbit was about 11 hours, 55 minutes. NASA hopes that period will decrease by at least several minutes, potentially up to 10 minutes.
“DART’s success provides a significant addition to the essential toolbox we must have to protect Earth from a devastating impact by an asteroid,” said Lindley Johnson, NASA’s Planetary Defense Officer. “This demonstrates we are no longer powerless to prevent this type of natural disaster. Coupled with enhanced capabilities to accelerate finding the remaining hazardous asteroid population by our next Planetary Defense mission, the Near-Earth Object (NEO) Surveyor, a DART successor could provide what we need to save the day.”
Theresa Cross contributed to this story
Video courtesy of NASA
Sean Costello
Sean Costello is a technology professional who also researches, writes about and speaks publicly on the inspiring lessons within international space flight program. Prior to joining SpaceFlight Insider in early 2014, Costello was a freelance photographer and correspondent covering shuttle-era Kennedy Space Center launches for various radio and print news organizations.
