NASA’s DART mission, aimed at deflecting threatening asteroids, has been hailed as a success. However, a recent study reveals an unexpected consequence of this mission: rocky debris could potentially collide with Mars in the future.
Repercussions of the DART mission
In 2022, NASA deliberately caused an impact between a spacecraft and an asteroid named Dimorphos in order to alter both the asteroid’s orbit and the trajectory of Didymos, another larger asteroid around which it orbits. Originally conceived as a pilot program, the Double Asteroid Redirection Test (DART) mission aimed to divert potentially deadly near-Earth asteroids, the same size as the one that killed the non-avian dinosaurs.
The DART mission was hailed as a great success by scientists, with subsequent research showing that the shape of Dimorphos had changed significantly and the small asteroid’s orbit had been shifted by 32 minutes. The mission, however, had an unexpected result: during the collision with Dimorphos, the spacecraft expelled 37 boulders measuring up to 6.7 meters into space.
Trajectory of debris and impact on Mars
Although it appears that none of these blocks will have any impact on Earth, scientists have always been interested in the potential destinations of these enormous rocks. Now they might have an answer. In a preprint paper awaiting peer review, the researchers describe the debris’ likely destination: Mars.
Marco Fenucci, co-author of the new study and a mathematician at the European Space Agency’s Near-Earth Object Coordination Center, tracked the trajectory of the boulders and ran simulations to predict their position in 20,000 years. Of course, such a distant prognosis involves many unknowns. But according to their predictions, this debris could cross the orbit of Mars in around 6,000 years.
However, the exact impact of these rocks on the surface of the Red Planet depends on their composition. The study authors predict that if their structure is unstable, they will likely explode or burn up in the thin Martian atmosphere. On the other hand, if they are strong enough, they will create a fairly large impact crater.
Warnings for future space missions
This study also raises concerns that missions similar to DART could release more space debris. The majority of asteroids whose trajectory scientists wish to adjust are close to Earth. Many of them, including Dimorphos, will be “rubble pile” asteroids, that is, piles of stones similar to those released during the DART experiment.
Before launching a DART-type planetary defense mission closer to Earth, scientists will need to be able to anticipate the quantity and direction of this debris in order to truly defend our planet. According to Fenucci, there will be a problem if we send more objects into space that risk impacting Earth.
Currently, no near-Earth asteroids pose a threat of colliding with Earth in the near future, but it is essential that astronomers continue to monitor these celestial objects to ensure our long-term safety.
