On Monday, NASA’s DART (Double Asteroid Redirection Test) successfully collided with its asteroid target after flying in space for 10 months as part of the first planetary defense technology demonstration in the world.
The successful impact was officially announced by Mission Control at the Johns Hopkins Applied Physics Laboratory in Maryland around 7:14 p.m. EDT. NASA Administrator Bill Nelson said:
“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.”
He added that the defense test was part of the agency’s efforts to protect planet Earth:
“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.”
DART reportedly targeted an asteroid moonlet called Dimorphos, which encircles a larger asteroid named Didymos.
Although none of the asteroids are a threat to the Earth, the successful impact of the defense test showed that NASA may be able to shift the orbits of asteroids that are threatening to the Earth in the future.
What is DART?
Double Asteroid Redirection Test, or DART, is a spacecraft created as part of the first mission launched by NASA to study the process of “asteroid deflection” by altering its motion in space with the help of “kinetic impact.”
The mission was launched in November 2021 with the goal of colliding the $325 million and 1,200-pound spacecraft with a target asteroid to change its path and speed in space.
Scientists then selected an asteroid system located closer to Earth, consisting of a 160-meter sized asteroid called Dimorphos orbiting a larger 780-meter asteroid, Didymos, as their target.
The successful test showed that NASA can intentionally make a spacecraft collide with an asteroid with the aim of deflecting its path to prevent the asteroid from coming into contact with the Earth.
The test will allow scientists to study the effectiveness of the process and help them understand ways in which the approach can be applied to defend against Earth-threatening asteroids in the future.
Whether the test successfully moved the asteroid will be revealed after a detailed ground-level study conducted by researchers in the coming weeks.
Exploring the results of NASA’s DART test
NASA’s DART reportedly spent 306 days navigating through space to reach its destination asteroid system for the agency’s first attempt to move an asteroid. Around 3 p.m. on Monday, scientists saw the presence of a rock appear on the spacecraft’s camera as a few pixels of white light.
As the spacecraft inched closer to its destination, the view of the asteroid grew larger, eventually appearing as a “pinprick of light” and taking a rugged spherical shape. The cameras in the probe turned blank as officials detected a loss of signal at approximately 4.14 p.m.
Controllers at JHU-APL exclaimed with joy as the DART successfully crashed into the target asteroid and destroyed itself as part of the intentional collision. According to the BBC, the initial calculations revealed that the impact was 17m off the center of Dimorphos.
The publication noted that prior to the crash, Dimorphos took approximately 11 hours and 55 minutes to circle its partner Didymos. The rate was reportedly reduced by a few minutes after the collision.
NASA’s Planetary Defense Officer Lindley Johnson said the successful defense test would help the agency in their preparation to protect the Earth from the threat of asteroids:
“DART’s success provides a significant addition to the essential toolbox we must have to protect Earth from a devastating impact by an asteroid. 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.”
Thomas Zurbuchen, Associate Administrator for the Science Mission Directorate at NASA Headquarters, said officials are now confident that spacecrafts can be successfully used to impact even a small body in outer space:
“Planetary Defense is a globally unifying effort that affects everyone living on Earth. Now we know we can aim a spacecraft with the precision needed to impact even a small body in space. Just a small change in its speed is all we need to make a significant difference in the path an asteroid travels.”
APL Director Ralph Semmel mentioned that the successful results of the test exceeded the expectations:
“This first-of-its-kind mission required incredible preparation and precision, and the team exceeded expectations on all.”
“Beyond the truly exciting success of the technology demonstration, capabilities based on DART could one day be used to change the course of an asteroid to protect our planet and preserve life on Earth as we know it.”
As per NASA, the Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO), the sole instrument of the spacecraft, along with the Small-body Maneuvering Autonomous Real Time Navigation (SMART Nav) algorithms and “a sophisticated guidance, navigation and control system” allowed DART to identify and differentiate between the two asteroids.
In the forthcoming weeks, a global team will observe the ejecta produced and measure the exact changes made in Dimorphos’ orbit to determine the effectiveness of DART’s deflection of the asteroid.
The investigation team will also observe Dimorphos using ground-based telescopes to confirm if DART’s impact has successfully altered the asteroid’s orbit around Didymos. NASA mentioned that researchers are expecting the impact to shorten Dimorphos’ orbit by "about 1%, or roughly 10 minutes."
Speaking on the success of the defense test, NASA’s Director of Planetary Science Dr Lori Glaze said:
"We're embarking on a new era of humankind, an era in which we potentially have the capability to protect ourselves from something like a dangerous hazardous asteroid impact. What an amazing thing; we've never had that capability before.”
JHU-APL mission systems engineer Dr Elena Adams added that "earthlings should sleep better" after knowing they have moved closer to a planetary defense solution. The success of the DART probe will officially be determined after researchers study the changes made in the orbit of Dimorphos.
NASA also noted that the European Space Agency’s Hera project will conduct detailed surveys of both Dimorphos and Didymos in nearly four years.The project will reportedly focus on the exact measurement of Dimorphos’ mass and study the crater that was created by the latest collision.