Debris from NASA's DART Impact Could Illuminate Mars, But Not Earth

Recent research into the aftermath of NASA's Double Asteroid Redirection Test (DART) reveals that while debris from the spacecraft's collision with the asteroid Dimorphos might produce meteors on Mars, Earth is unlikely to experience a meteor shower. 

The DART spacecraft, which struck Dimorphos on September 26, 2022, was designed to test whether a kinetic impact could alter the orbit of a potentially hazardous asteroid. The mission was a success, as Dimorphos was pushed into a shorter orbit around its parent asteroid, Didymos. Neither asteroid posed a threat to Earth; they were simply used for testing purposes.

Observations of Ejected Debris

The impact created a significant crater on Dimorphos and ejected a substantial amount of debris. This material, which was observed by the Light Italian Cubesat for Imaging of Asteroid (LICIACube), was ejected at velocities up to 500 meters (1,640 feet) per second. LICIACube, which had accompanied DART to capture images of the collision’s aftermath, recorded particles ranging from a micron to several centimeters in size.

Further observations from the Large Array Survey Telescope (LAST), the Wise Observatory’s 28-inch telescope, and the NASA Swift satellite’s ultraviolet and optical instruments suggested that additional microscopic particles were ejected at speeds ranging from 1,400 to 1,800 meters (about 4,600 to 5,900 feet) per second.

Modeling the Spread of Debris

A team led by Eloy Peña-Asensio from the Politecnico di Milano and Michael Küppers, project scientist for the European Space Agency's Hera mission, have modeled the potential spread of this debris across the solar system. Their simulations, which accounted for the gravitational influences of Didymos, Dimorphos, the sun, and other planets, revealed some intriguing possibilities.

According to their main simulation, which tracked 3 million particles of varying sizes, the slower-moving debris could reach Mars within 13 years, by 2035. This is due to the orbit of the Didymos-Dimorphos binary intersecting with Mars’ orbit. However, the simulation indicated that none of these particles are expected to reach Earth.

Potential for Earthly Meteors

The secondary simulation, which considered faster-moving ejecta, suggested that while the faster particles could potentially reach Mars within 5 years and Earth within 7 years, they would be too small to produce a visible meteor shower on Earth. "In our main simulation, no particles reach Earth at velocities up to 1,000 meters (3,280 feet) per second," Peña-Asensio explained. “Only particles ejected at velocities of 1,500 meters (4,900 feet) per second or higher reach Earth, and this occurs exclusively in the secondary simulation.”

Nevertheless, if larger particles were missed by LICIACube or if they were slightly larger than observed, it remains possible for some to reach Earth and create visible meteors. "Only future meteor observation campaigns can verify this," Peña-Asensio noted.

Origins of the Debris

The simulations also identified the potential origins of the debris arriving at Earth and Mars. The debris likely to create a meteor shower on Mars would come from the northern part of the impact site, while the smaller, fast-moving particles that might reach Earth would originate from the southwestern part of the crater.

Peña-Asensio concluded, “Impacts like DART and the resulting ejecta highlight the ongoing exchange of material between planetary bodies, asteroids, comets, and other celestial objects.”

So, while Earth’s skies might remain clear of meteor showers from Dimorphos' debris, Mars could enjoy a spectacular display of shooting stars in the coming decade. 

This research is available as a pre-print on the paper repository arXiv.