A Japanese probe has left Earth to reach Phobos, a small moon of Mars, and attempt to bring back pieces of it.
The mission is called MMX, for Martian Moons eXploration. It launched from Japan on October 20, 2026, aboard an H3 rocket. About an hour after liftoff, the probe separated from the launch vehicle as planned.
© DLR (CC BY-NC-ND 3.0)
The news is good: on October 21, the Japanese space agency JAXA announced that the first critical operations had been completed. The solar panels were deployed, the probe adopted the correct orientation, and the systems needed for its operation responded properly. However, many instruments still need to be checked before the long journey.
Why study a moon of Mars? Because Phobos and its neighbor Deimos pose a mystery. They are very small and have irregular shapes. Some researchers think they are asteroids captured by Mars. Others believe they formed from debris left by an ancient impact around the planet.
MMX should help determine which explanation is correct. It will observe both moons, but will focus on Phobos. It will approach its surface and collect at least 10 grams of material. A small amount, but potentially enough to reveal the composition and history of this moon.
The spacecraft is also carrying a small wheeled robot called Idefix, developed in France and Germany. Its role will be to move across Phobos and examine the ground directly. It will not be an easy trip: gravity there is so weak that a movement that is too sudden could make the robot take off.
Arrival in the Mars region is expected in 2027. The probe will then spend several years studying Phobos and preparing the sampling operations. If every step succeeds, a capsule will return the samples to Earth in 2031, where they can be examined in laboratories.
These pieces of Phobos could contain clues about how the Martian system formed. For now, the launch and initial checks have been successful: the collection and return still remain to be completed.