On September 26th, 2022, NASA’s DART mission made headlines by smashing into Dimorphos, a tiny moonlet orbiting the asteroid Didymos, in a bold test of planetary defense.
This not only showcased a way to shield Earth from potential asteroid collisions but also opened the door to new challenges and possibilities in space exploration. As a follow-up, the European Space Agency (ESA) will launch its Hera mission, set to meet with the double-asteroid system by October 2026. Hera will conduct an in-depth post-impact analysis of Dimorphos. It will confirm whether the kinetic impact method can be a dependable strategy for planetary defense.
While this method could indeed divert asteroids away from Earth, it also raises concerns about the creation of debris that could eventually reach Earth or other celestial bodies. A recent study led by Dr. Eloy Peña-Asensio, a Research Fellow with the Deep-space Astrodynamics Research and Technology (DART) group at the Polytechnic Institute of Milan explored the potential for the debris from the DART impact to reach Earth and Mars as meteors.
By conducting dynamic simulations, the team discovered that the ejecta from the DART mission could reach Mars and the Earth-Moon system within a decade. These findings are crucial as they provide insights into how space debris might behave over time.
“LICIACube provided crucial data on the shape and direction of the ejecta cone immediately following the collision,” Peña-Asensio explained.
This data, coupled with simulations, revealed that particles ejected at velocities below 500 m/s could reach Mars in about 13 years, while those traveling at speeds exceeding 1.5 km/s might reach Earth in as little as seven years.
However, the research suggests that it may take up to 30 years before any of this debris is observable on Earth. Furthermore, Dr. Peña-Asensio noted, “These faster particles are expected to be too small to produce visible meteors, based on early observations.”
Nonetheless, the possibility of a new meteor shower dubbed the “Dimorphids,” remains, with future meteor observation campaigns set to provide definitive answers.
This research shows the importance of the DART mission and its companion missions in advancing our understanding of space debris and planetary defense.
“A unique aspect of the DART mission is that it is a controlled impact experiment, i.e., an impact where the impactor properties (size, shape, mass, velocity) are accurately known,” Michael Küppers, Project Scientist of the ESA’s Hera mission emphasized.