2026 Mars mission will set out to solve the mystery of its moons
The Japan Aerospace Exploration Agency will be launching the Martian Moons eXploration mission next year, which should finally tell us how Mars acquired the moons Phobos and Deimos
Space
The Japan Aerospace Exploration Agency will be launching the Martian Moons eXploration mission next year, which should finally tell us how Mars acquired the moons Phobos and Deimos
By Alex Wilkins
30 December 2025
Facebook / Meta Twitter / X icon Linkedin Reddit Email

The MMX probe will visit Mars’s moons
JAXA
The mystery of how Mars acquired its moons, Phobos and Deimos, may start to be unravelled in 2026 with the launch of a spacecraft that will eventually bring a chunk of Phobos back to Earth.
“We are sure about the origin of the Earth’s moon, but we don’t know how Phobos and Deimos got there,” says Emelia Branagan-Harris at the Natural History Museum in London. “Understanding the origins of Phobos and Deimos, and how they came to be orbiting Mars, can hopefully tell us a bit about the evolution of Mars in general and its history.”
There are two competing hypotheses for how these moons came to orbit Mars: the Red Planet could have captured them as a pair of asteroids, which were either conjoined and later separated or closely orbited each other, or they could have been produced from an asteroid smashing into Mars itself, like how Earth’s moon formed.