2026 Mars Mission Aims to Uncover Satellite Secrets

The mystery surrounding the origins of Mars’s moons, Phobos and Deimos, may soon be unraveled with the launch of the MMX spacecraft, set to return samples from Phobos to Earth in 2026.

“While we understand the origin of Earth’s moon, the origins of Phobos and Deimos remain unclear,” says Emelia Brannagan-Harris from the Natural History Museum in London. “By exploring the origins of these moons, we aim to gain insights into Mars’s evolutionary history.”

There are two leading theories regarding how these moons came to orbit Mars. The first theory suggests that they are remnants of asteroids that either merged and then separated or closely orbit each other. The second theory posits that they may have formed from an asteroid impact on Mars, similar to the formation of Earth’s moon.

Currently, evidence supports neither scenario definitively. However, the Japan Aerospace Exploration Agency’s Mars Moon Explorer (MMX), scheduled for launch in 2026, is equipped to clarify which theory holds true. This spacecraft will observe both moons and send a rover to gather samples from Phobos’s surface and subsurface.

If the observations reveal a prevalence of carbon-rich materials and water, it could support the theory of asteroid capture. Conversely, if such materials are absent, we may need to await the analysis of the collected samples, expected to return to Earth by 2031.

The Phobos samples will include both surface material and samples from beneath the surface. Testing this material will allow scientists to investigate signs of past dissolution, potentially indicating interactions with Mars’s atmosphere or surface.

Regardless of the origins of Phobos, its close orbit around Mars suggests it may hold well-preserved samples from early Mars. “Phobos might also contain ancient debris from Mars’s period of liquid water, offering significant insights into the planet’s history,” Brannagan-Harris emphasizes.