One Asteroid Strike May Explain Two Mysteries of Mars' Moon Deimos

Topic: Space

A team led by the University of Bern found evidence that a single asteroid collision may have reshaped Deimos, the smaller moon of Mars. The research used computer simulations and images from ESA's Hera spacecraft to conclude that one impact could account for both the moon's large southern depression and its smooth surface.

Deimos is the smaller and more distant of Mars' two moons. It has a roughly oval shape and a prominent depression near its south pole. Its surface looks strikingly different from that of Phobos, Mars' other moon.

A team led by Dr. Sabina Raducan investigated whether the southern depression and the widespread layer of debris on Deimos could share the same origin. The international collaboration included researchers from several institutions, including the Observatoire de la Côte d'Azur, the University of Arizona, and the University of Tokyo.

Using high-resolution simulations produced with the Bern Smoothed Particle Hydrodynamics (SPH) code, the team found that the distinctive depression near the south pole was most likely produced by a single asteroid impact. The same collision could also have generated the regolith that now blankets much of the moon.

Why It Matters

This discovery can help guide future missions to Mars and its moons, including the Japan Aerospace Exploration Agency's (JAXA) Martian Moons eXploration (MMX) mission.

Key Facts

• Deimos is the smaller moon of Mars, with a roughly oval shape and a prominent depression near its south pole.
• The southern depression on Deimos was likely caused by a single asteroid impact.
• The same collision could have generated the regolith that now blankets much of the moon.
• The research used computer simulations and images from ESA's Hera spacecraft to reach this conclusion.
• The findings can help guide future missions to Mars and its moons.

Key Terms

Smoothed Particle Hydrodynamics (SPH)

A method of simulating collisions involving asteroids, comets, and planets using millions of individual particles.

Regolith

Loose dust and rocky debris that covers the surface of Deimos.

Hera spacecraft

A European Space Agency (ESA) space probe that flew past Deimos to collect data on its surface and composition.

Implications

This discovery can help guide future missions to Mars and its moons, including the Japan Aerospace Exploration Agency's (JAXA) Martian Moons eXploration (MMX) mission.