Debris from NASA's DART Mission Could Potentially Reach Earth and Mars

Debris from NASA's DART Mission Could Potentially Reach Earth and Mars
by Erica Marchand
Paris, France (SPX) Sep 11, 2024

NASA's Double Asteroid Redirect Test (DART) mission, which struck the asteroid Dimorphos in 2022, has not only altered the asteroid's orbit but has also created a plume of debris that may eventually reach both Earth and Mars, according to new simulations. The debris, although harmless, could potentially be observed as meteors.

On September 26, 2022, NASA's DART spacecraft, weighing approximately half a ton, collided with the 151-meter-wide Dimorphos asteroid at a speed of 6.1 km/s. This impact, part of a global planetary defense collaboration, successfully shortened Dimorphos' orbit around the larger Didymos asteroid by more than 30 minutes.

The European Space Agency (ESA) will further investigate this event with its Hera mission, launching in October. The Hera spacecraft is set to arrive at Dimorphos in late 2026, where it will conduct a thorough analysis of the asteroid's structure and composition. This data will be crucial in refining the kinetic impact method as a reliable planetary defense strategy.

Michael Kueppers, a scientist on the Hera mission, explained the significance of the impact: "The DART impact offers a rare opportunity to investigate the delivery of ejecta to other celestial bodies, thanks to the fact that we know the impact location and that this impact was observed by the Italian LICIACube deployed from DART as well as by Earth-based observers."

Researchers conducted simulations using three million particles, grouped into different size categories, to understand how the ejecta might behave. They modeled particles measuring 10 cm, 0.5 cm, and 30 microns, traveling at speeds between 1 m/s and 2 km/s.

Eloy Pena-Asensio, the lead author of the study from the Department of Aerospace Science and Technology at Politecnico di Milano, highlighted the possibility of debris reaching other planets: "We identified ejecta orbits compatible with the delivery of meteor-producing particles to both Mars and Earth. Our results indicate the possibility of ejecta reaching the gravitational field of Mars in 13 years for launch velocities around 450 m/s, while faster ejecta launched at 770 m/s could reach its vicinity in just seven years. Particles moving above 1.5 km/s could reach the Earth-Moon system in a similar timescale."

The study suggests that fragments from Dimorphos might reach Earth's vicinity, but only small particles are likely to make it to our atmosphere. Even if this happens, Pena-Asensio notes, "We will witness the first human-made meteor shower."

Josep M. Trigo-Rodriguez, from the Spanish Institute of Space Sciences, commented on the exciting potential for meteors resulting from DART's impact: "We were amazed to discover that it is possible for some centimetre-sized particles to reach the Earth-Moon system and produce a new meteor shower."

The distribution of the debris depends on its position within the DART impact plume. Material on the northern side of the plume is more likely to travel toward Mars, while debris from the southwestern portion of the plume could head toward Earth.

The particles expected to reach Earth are most likely the smallest ones launched at the highest velocities, and it remains unclear whether these will be large enough to create visible meteors. However, ongoing monitoring of the night sky is crucial to confirm this possibility.

Michael Kueppers added, "Our accurate knowledge of the impact site and impactor properties in terms of size, mass and velocity plus the observations of the ejecta are what allowed us to estimate the long-term fate of the material leaving the Didymos system."

Combined with the data that Hera will gather, scientists will have a comprehensive understanding of both the DART impact and the resulting debris.

Currently, over 1000 known meteoroid streams intersect Earth's orbit, contributing to well-known meteor showers like the Perseids and the Taurids. The study on DART's debris follows a similar method, calculating the potential trajectory and characteristics of meteors that could originate from the impact.

Kueppers explains further: "The exciting thing is the prospect of identifying and observing meteors linked to the DART impact, either on Earth or perhaps one day even on Mars, with their brightness and colour revealing details of their makeup."

Any potential meteors from DART are expected to be slow-moving and likely visible in the southern hemisphere, primarily during May.

Hera, the spacecraft tasked with a detailed follow-up investigation, has already been transported to Cape Canaveral for its launch aboard a SpaceX Falcon 9 rocket this October.

Research Report:Delivery of DART Impact Ejecta to Mars and Earth: Opportunity for Meteor Observations