The Red Planet holds many mysteries, which our landers and probes are helping scientists solve. Among them is the question of where the two Martian moons came from and how they got there. Phobos and Deimos look more like asteroids than moons, and that has caused many planetary scientists to look for their origin somewhere else in the solar system.
Asteroid Capture Theory
Both have many characteristics in common with two types of asteroids common in the belt: C- and D-type asteroids.
- It is possible that Phobos and Deimos could have been a binary pair, bound together by gravity when they were captured. Over time, they would have separated into their current orbits, forming the asteroid belt.
Large Impact Theory
Mars likely suffered a large collision very early in its history, similar to Earth’s Moon.
- Both impacts would have sent a hot, plasma-like material into a concentric orbit about the infant planets, eventually gathering into a ring of molten rock that eventually formed the Moon.
Exploration of Phobos and Deimos
More information is needed, and the best way to get it is to do an in-situ exploration
- A probe to land on one or both of these moons
- To do it right, scientists would send a lander to grab some soil and rocks and return it to Earth for study
- Alternatively, part of a mission could be diverted to land people on the moons to do a more nuanced geological study
