Human-Made Meteor Shower Could Occur After NASA’s DART Impact on Asteroid

In 2022, NASA’s DART spacecraft intentionally collided with the small asteroid Dimorphos, creating a substantial amount of debris. This impact could potentially lead to the first human-made meteor shower, referred to as the Dimorphids, according to a recent study. The DART mission, or Double Asteroid Redirection Test, was designed to evaluate asteroid deflection technology, a vital component of planetary defense. The mission’s goal was to determine if crashing a spacecraft into an asteroid at high speed—13,645 miles per hour (6.1 kilometers per second)—could alter the motion of a space object.

Neither Dimorphos nor Didymos, the larger asteroid it orbits, poses any threat to Earth. However, the double-asteroid system served as an ideal candidate for testing deflection methods, given that Dimorphos is similar in size to asteroids that could pose a risk to our planet. For nearly two years, astronomers have monitored the results of the collision using ground-based telescopes. The findings confirmed that the DART spacecraft successfully altered Dimorphos’s trajectory, reducing its orbital period, or the time it takes to complete a single orbit around Didymos, by about 32 to 33 minutes.

The collision also generated over 2 million pounds (nearly 1 million kilograms) of rocks and dust, equivalent to filling six or seven rail cars. The final destination of this debris has remained uncertain until now. New research indicates that fragments from Dimorphos could reach the vicinity of Earth and Mars within one to three decades. Some debris might even reach Mars as soon as seven years from now, while smaller fragments could enter Earth’s atmosphere within the next 10 years. The study detailing these findings has been accepted for publication in the Planetary Science Journal.

“This material could produce visible meteors (commonly called shooting stars) as they penetrate the Martian atmosphere,” explained Eloy Peña Asensio, the lead study author and a postdoctoral researcher at Italy’s Polytechnic University of Milan. He added, “Once the first particles reach Mars or Earth, they could continue to arrive intermittently and periodically for at least the next 100 years, which is the duration of our calculations.”

Predicting the Movement of Space Debris

The debris fragments vary in size, ranging from tiny sand-like particles to pieces the size of smartphones. According to Peña Asensio, none of the debris poses any risk to Earth. “They would disintegrate in the upper atmosphere through a process known as ablation, caused by friction with the air at hypervelocity,” he stated. “There is no possibility of Dimorphos material reaching Earth’s surface.”

However, predicting when this debris might reach Earth is challenging and depends on estimating the fragments’ speed. During the DART mission, a small satellite named LICIACube separated from the spacecraft before impact to capture images of the collision and the resulting debris cloud. “This crucial data has enabled and continues to enable detailed analysis of the debris produced by the impact,” Peña Asensio noted.

Using data from LICIACube and the supercomputing resources of the Consortium of University Services of Catalonia, the research team simulated the paths of 3 million particles created by the collision. The modeling considered various potential trajectories and velocities of the particles within the solar system and how solar radiation might influence their movement.

Previous studies had suggested that debris from Dimorphos could reach Earth or Mars, but this new research refined those predictions based on post-impact data from LICIACube. The findings indicate that if the debris was ejected from Dimorphos at speeds of 1,118 miles per hour (500 meters per second), some fragments could reach Mars. Smaller, faster debris traveling at 3,579 miles per hour (1,600 meters per second) might reach Earth.

Although the study indicates that the fastest-moving particles could potentially reach Earth in less than 10 years, there are still uncertainties about the debris’s nature. Peña Asensio stated that while a Dimorphids meteor shower is unlikely, it cannot be entirely ruled out. “If it did occur, it would be a small, faint meteor shower,” he said. “The resulting meteor shower would be easily identifiable on Earth, as it would not coincide with any known meteor showers. These meteors would be slow-moving, with peak activity expected in May, and primarily visible from the southern hemisphere, seemingly originating from near the Indus constellation.”

The researchers also speculated that debris from Dimorphos could potentially reach other nearby asteroids, although this scenario was not explored in their study.

Observing the Aftermath

While some ejected debris was expected following the impact, the possibility of it reaching Earth or Mars could only be calculated after the event, noted Michael Küppers, a planetary scientist at the European Space Astronomy Centre and co-author of the study. “Personally, initially I was surprised to see that, although the impact happened close to Earth (at about an 11-million-kilometer distance), it is easier for the impact ejecta (debris) to reach Mars than to reach Earth,” Küppers remarked. “I believe the reason is that Didymos crosses the orbit of Mars, but stays just outside the orbit of Earth.”

Debris can also be ejected from other near-Earth asteroids, such as Phaethon, which is responsible for the Geminid meteor shower that occurs each December. Studying the debris from the DART impact could help scientists predict when such material might reach Earth or Mars, suggested Patrick Michel, an astrophysicist at the National Centre for Scientific Research in France, who was not involved in the study. “This study tries to quantify this possibility and confirms that it may happen, even if it relies on modeling that has its own uncertainties,” Michel said.

Future observations could provide researchers with more accurate measurements of the debris’s mass and velocity, enabling them to better predict potential meteor activity. The upcoming Hera mission, set to launch in October by the European Space Agency, will observe the aftermath of the DART impact. Scheduled to arrive at the asteroid system by late 2026, Hera, along with two CubeSats, will examine the composition and mass of Dimorphos and its transformation due to the impact. The mission will also assess the momentum transferred from the spacecraft to the asteroid.

“Is there an impact crater, or was the impact so large that Dimorphos was globally reshaped?” asked Küppers, who is also a project scientist for the Hera mission. “From ground-based data, we have some evidence for the latter. Hera will tell us for sure. Also, we will see if the impact left Dimorphos (tumbling).”

Overall, the Hera mission will provide astronomers with critical insights into the dynamical evolution of debris generated by such impacts, particularly in a complex double-asteroid system like Didymos and Dimorphos, Michel concluded.