Mars’ moons, Phobos and Deimos, could be asteroid debris, new research shows
According to recent simulations, Mars’ two moons, Phobos and Deimos, could have come from the debris of an asteroid that was torn apart by the planet’s gravity. Research published in Icarus suggests that this scenario could explain the unique features of these moons, which differ significantly from the typical spherical moons seen in the Solar System. The potato-like shapes and circular equatorial orbits of these moons have long puzzled scientists, prompting new theories about their formation.
Theories behind the origins of Phobos and Deimos
Two primary theories have dominated the discussion about the formation of these moons. They are said to be asteroids captured by Mars’ gravity. However, this hypothesis does not take into account their stable, nearly circular orbits. The second theory suggests that Phobos and Deimos may have formed from debris after a massive collision involving Mars. Jacob Kegerreis, a planetary scientist at NASA’s Ames Research Center, believes a hybrid scenario could provide a plausible answer.
Kegerreis and his team hypothesize that an asteroid may have been captured by Mars’ gravity but then torn apart, creating a ring of debris. Over time, this material could have coalesced to form the moons, inheriting the circular orbits observed today.
Simulations offer new insights
Hundreds of supercomputer simulations were run to test the hypothesis. By varying the asteroid’s size, speed and rotation, researchers discovered observed that under certain conditions rings of debris were continuously formed. Kegerreis explained that in several scenarios they saw material capable of forming a disk.
Upcoming mission to provide answers
The Japan Aerospace Exploration Agency’s Mars Moons Exploration mission, scheduled for launch in 2026, aims to collect material from Phobos. This analysis could determine whether the moons share a composition with Mars, supporting the collision theory, or resemble asteroids with water-rich compounds, supporting the fragmented asteroid hypothesis.
The findings from this mission could shed light on the moons of Mars and help understand moon formation around exoplanets, broadening our understanding of planetary systems.
