Japan is launching a mission to Mars’s largest moon Phobos — SkimNews
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- JAXA's MMX spacecraft launches from Tanegashima Space Center on 20 October toward Phobos, Mars's larger moon, with arrival expected in August 2027.
- MMX will orbit alongside Phobos to build a detailed surface map, also observing Deimos along the way, before making one or two brief landings to collect samples.
- JAXA plans to deploy IDEFIX, the first wheeled rover ever placed on such a small cosmic body, partly to test whether a rover can function in ultra-low gravity.
- MMX carries two sampling devices — a gas-puff mechanism that blows dust and pebbles into a container, and a hollow cylinder that drills several centimetres into the surface.
- The samples are expected to return to Earth in 2031, which scientists say could settle whether Phobos and Deimos are captured asteroids or fragments of a giant impact on Mars.
- NASA scientist Tom Statler said the samples will illuminate "that early era when Earth and the other inner planets may have been acquiring much of their water and organic compounds."
- Phobos's surface may also contain Martian dust kicked up by ancient impacts and preserved for billions of years, potentially shedding light on Mars's own history.
Why it matters: No samples have ever been returned from Phobos, so MMX's 2031 homecoming would deliver the first ground-truth data on the moons' composition — directly settling a 100-year-old formation debate and, if lucky, providing a free archive of Martian impact debris preserved for billions of years.
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