Japan launches Phobos sample mission

Japan's Martian Moons eXploration (MMX) mission, led by the Japan Aerospace Exploration Agency (JAXA), launched on October 20, 2026, from the Tanegashima Space Center aboard an H3 rocket. The spacecraft aims to collect samples from Phobos, one of Mars' moons, and return them to Earth by 2031.

Phobos: Mars' larger moon

Phobos is the larger of Mars' two moons, measuring 27 × 22 × 18 kilometers. It is irregularly shaped, orbits Mars three times a day, and is slowly moving closer to the planet at a rate of 1.8 meters every century.

Phobos' mysterious origins

The origins of Phobos and its smaller sibling, Deimos, remain uncertain. The two moons may have been captured asteroids or debris from a massive collision on Mars. Scientists are still unsure which scenario is correct.

First mission to return samples from a Martian moon

No previous mission has returned samples from Phobos or Deimos. The MMX mission is the first to plan to land on Phobos and bring material back to Earth. It has a budget of $578 million and involves collaboration with the European Space Agency (ESA) and other space agencies.

Mission timeline and operations

The spacecraft, weighing five tons, is expected to reach Mars orbit in August 2027. It will deploy a small rover named Idéfix to explore Phobos for 100 days, identifying safe landing sites for MMX. The main spacecraft will then collect at least 10 grams of material from Phobos.

Return to Earth and scientific goals

After collecting samples, MMX will fly by Deimos and head back to Earth, arriving in 2031. Scientists hope the samples will reveal more about the moons' formation and the conditions that may have contributed to life on planets like Earth.

Other Mars sample missions in progress

NASA's Perseverance rover, which has been exploring Mars since 2021, has collected samples, but plans to return them to Earth were paused under the Trump administration. China's Tianwen-3 mission also aims to return Martian samples, with an expected return date of around 2031.