Exploring the Mystery: How Mars’s Moons Were Formed

Mars’s small and peculiar moons, Phobos and Deimos, may have been born from the catastrophic breakup of a larger asteroid that ventured too close to the planet, according to recent computer simulations.

The new model suggests that the asteroid entered Mars’s Roche limit — the critical distance at which a planet’s tidal forces overpower an object’s own gravity.

The asteroid tore apart, leaving debris that eventually formed the two moons.

Jacob Kegerreis of NASA’s Ames Research Center expressed enthusiasm about the findings, saying, “It’s exciting to explore a new possibility for the formation of Phobos and Deimos — unique moons that, besides Earth’s, are the only ones orbiting a rocky planet in our solar system.”

Phobos and Deimos have long been a mystery. With diameters of just 16 miles (26 km) and 10 miles (16 km), respectively, their irregular shapes resemble asteroids.

This has led scientists to speculate that they might be captured objects from the asteroid belt.

However, the moons’ circular orbits, closely aligned with Mars’s equatorial plane, contradict the typical characteristics of captured bodies, which often follow eccentric, tilted, or retrograde trajectories.

For instance, Neptune’s moon Triton and Saturn’s moon Phoebe are prime examples of captured objects with such irregular orbits.

The new theory adds to the debate about Mars’s moons and their origins, offering a fresh perspective on how these enigmatic celestial objects came to orbit the Red Planet.