A spacecraft headed for Mars is carrying an unusually small shopping list: at least 10 grams of material from Phobos. If Japan’s Martian Moons eXploration mission succeeds, that handful of grains could help resolve how the Red Planet acquired its two moons.
MMX launched aboard an H3 rocket from Tanegashima Space Center on October 20 in Japan, corresponding to October 19 in the United States. Led by the Japan Aerospace Exploration Agency, or JAXA, the mission aims to deliver its samples to Earth in 2031.
The samples would be the first returned from a moon other than Earth’s own. NASA, the European Space Agency, France’s CNES and the German Aerospace Center, DLR, are contributing instruments, technology and operational support. The mission combines remote observations, a small rover and spacecraft landings to investigate a question that telescope images alone have not settled.