Japan is preparing to launch an ambitious mission to collect samples from Phobos, one of Mars’ two moons, in an effort to understand the formation of the Martian system and the origins of materials essential for life on Earth.
The Martian Moons eXploration (MMX) spacecraft, developed by the Japan Aerospace Exploration Agency (JAXA) with international partners, is scheduled for launch aboard an H3 rocket from Tanegashima Space Center on October 20. It is expected to reach Mars in about a year and spend up to three years studying Phobos before collecting at least 10 grams of surface material. The spacecraft will also observe Deimos, Mars’ other moon, before returning to Earth.
A French-German rover, IDEFIX, will examine the surface to help identify a suitable landing site. The mission could also provide insights into the technical challenges of travelling between Earth and Mars, supporting future crewed exploration.
Scientists are investigating two competing explanations for the moons’ origins. They may have formed from debris following a massive collision with Mars, or they could be asteroids captured by the planet’s gravity. Samples from Phobos could help distinguish between these possibilities.
The material may also preserve evidence of how water, volatile substances and organic compounds reached the inner Solar System, potentially contributing to conditions suitable for life on rocky planets.
Japan’s previous asteroid sample-return missions provide relevant experience, but operating close to Mars presents a significant challenge: overcoming its gravitational pull on the return journey. The findings could also offer a wider range of material than samples collected directly from Mars.
