Japan launches MMX mission toward Martian moons

Japan’s Martian Moons eXploration spacecraft launched aboard an H3 rocket on October 19, beginning a mission to study Phobos and Deimos and bring material from Phobos back to Earth. The Japan Aerospace Exploration Agency (JAXA), which leads the mission, is targeting a return in 2031. The spacecraft lifted off from Tanegashima Space Center in southwestern Japan. JAXA expects it to reach the Mars system in August or September 2027, after which it will survey Phobos and observe Deimos. The arrival, observations and sampling are planned milestones, not completed mission results. MMX is designed to collect at least 10 grams of material from Phobos and return it in a capsule. The target amount and 2031 delivery date remain objectives that depend on the spacecraft completing the stages ahead. No sample from either Martian moon has previously been returned to Earth. The mission is intended to investigate a question that remains unresolved: whether Phobos and Deimos formed from debris after an impact on Mars or are asteroids captured by the planet’s gravity. Close observations and laboratory analysis of any returned Phobos material could help scientists assess the competing...