NASA's DART (Double Asteroid Redirection Test) mission, which aimed to test the capability of deflecting an asteroid by crashing a spacecraft into it, has exceeded expectations by achieving higher precision than anticipated, four scientific studies have revealed. The successful mission outcome paves the way for future asteroid deflection efforts to protect the Earth from potential impact events.
In recent years, the possibility of a catastrophic asteroid impact on Earth has become an increasingly pressing concern. While such events are rare, the potential consequences are devastating, with the power to wipe out entire cities and even cause global extinctions. To address this threat, scientists and engineers have been working on ways to deflect or redirect near-Earth objects (NEOs) before they can reach our planet. The Double Asteroid Redirection Test (DART) mission represents a significant step forward in this effort.
The DART mission was launched by NASA in November 2021 with the goal of testing whether it is possible to change the trajectory of an asteroid by slamming a spacecraft into it. The target for the mission was a binary asteroid system known as Didymos and Dimorphos, which consists of a larger asteroid, Didymos, and a smaller one, Dimorphos, orbiting around it. Dimorphos, which is approximately 177 meters in diameter, was chosen as the impact target for DART.
DART reached Dimorphos and successfully collided with it
On September 26, 2022, DART reached Dimorphos and successfully collided with it at a speed of around 6.6 kilometers per second. The impact created a crater on the asteroid’s surface, and the resulting force was enough to change the asteroid’s orbit. When the DART spacecraft hit Dimorphos, it caused the asteroid’s orbital period around Didymos decreased by 33 minutes. Additionally, more than 1 million kilograms of debris were released into space, creating a dusty cloud that made the Didymos system temporarily brighter.
This cloud also formed a 10,000-kilometer (6,200 mi)-long tail that remained visible for several months. The success of the DART mission has demonstrated the feasibility of using kinetic impactors as a means of planetary defense against NEOs.
What we learned
The results of the DART mission were published in different papers, some in the scientific journal Nature on March 2, 2023. The papers describe the observations made by a fleet of ground-based and space-based telescopes before, during, and after the DART impact, as well as the modeling and analysis of the data. The papers conclude that the DART mission was a success and that the kinetic impactor approach is a promising option for deflecting or redirecting NEOs.
Derek Richardson, a professor of astronomy at UMD and a DART investigation working group lead, stated that although we currently cannot prevent natural disasters like hurricanes or earthquakes, we have learned that with adequate time, warning, and resources, we can prevent asteroid impacts. He emphasized that a small change in an asteroid’s orbit, with enough advance notice, could cause it to miss Earth and prevent catastrophic damage to our planet.
Improving and implementing
While the DART mission has shown that we have the technology to redirect asteroids, there is still much work to be done before we can say we are fully prepared to defend ourselves against a potential impact. Future missions will need to focus on improving our ability to detect and track NEOs and developing more effective deflection strategies. Nevertheless, the success of DART represents an important milestone in our ongoing efforts to protect our planet from the dangers of space.
In conclusion, the DART mission has demonstrated that it is possible to redirect NEOs using kinetic impactors, and its success has been confirmed in four papers published in Nature. While there is still much to learn about the threat posed by asteroids and the best ways to defend against them, the DART mission represents a significant step forward in our efforts to protect our planet from the dangers of space.
The scientific papers can be accessed through the following links. “Successful Kinetic Impact onto an Asteroid for Planetary Defense,” “Orbital Period Change of Dimorphos Due to the DART Kinetic Impact,” “Momentum Transfer from the DART Mission Kinetic Impact on Asteroid Dimorphos” and “Ejecta from the DART-produced active asteroid Dimorphos.”
