Japan has launched a spacecraft on the first-ever attempt to collect and return surface material from one of Mars’s moons, with scientists hoping the samples will help answer fundamental questions about how the solar system formed and whether life could have arisen on rocky planets. The Guardian reports that the Martian Moons Exploration (MMX) spacecraft lifted off from Tanegashima Space Centre aboard Japan’s H3 rocket at 4:41am local time on 20 October 2026, according to the Japan Aerospace Exploration Agency (Jaxa).
Jaxa declared the launch a success an hour after lift-off, when the spacecraft separated from the rocket’s upper stage. The mission carries a price tag of US$578m and involves five space agencies collaborating on a five-year programme.
What the mission will attempt to do
As of 15 October 2026, NASA Science had noted that the MMX spacecraft was expected to arrive at Mars in August 2027, with collection of surface material from Phobos scheduled no earlier than December 2028. Jaxa says the spacecraft will aim to gather at least 10g of soil and rock. The sample return to Earth is scheduled for 2031.
Phobos, the larger of Mars’s two moons, measures roughly 14 miles (22.5km) across and orbits the planet approximately 6,000km above its surface, completing three orbits per day. Once in orbit, the spacecraft will eject a small French-German rover named Idefix, after the terrier in the Asterix comics. Because gravity on Phobos is around 1/1,000th as strong as on Earth, the rover is expected to bounce for several minutes before settling, then spend 100 days surveying the surface to identify safe landing and sampling sites.
A four-legged stationary lander will then descend to gather the samples, spending only two hours on Phobos drilling and collecting material before returning to space. The spacecraft will also conduct several flybys of Deimos, Mars’s smaller moon, before leaving Martian orbit in November 2030, officials said.
What scientists hope the samples will show
Two competing theories exist for how Phobos and Deimos formed. The ‘giant impact’ hypothesis holds that a large body struck Mars, throwing debris into orbit. The ‘capture’ hypothesis proposes instead that the moons are asteroids drawn in by Mars’s gravity. Jaxa says establishing which account is correct could reveal ‘how a habitable environment for life might have arisen on the terrestrial planets’, referring to Mercury, Venus, Earth and Mars.
Nasa astrophysicist Tom Statler, who is involved in the Japan-led project, described the atmosphere at launch as one of ‘a lot of adrenaline and a lot of excitement and a lot of wow’. Markus Grebenstein, the Germany Space Agency’s rover chief, was quoted by The Guardian as saying: ‘It is a once-in-a-lifetime chance. We are part of the first sample return mission from the Martian system.’
In October 2026, NASA Science noted that NASA-supported researchers are working alongside international colleagues and will use mission data and returned samples to seek new information about Phobos’s origin and the evolution of the Mars system.
Where this fits in the broader race for Mars samples
No spacecraft has previously landed on Phobos or Deimos. Nasa has landed nine spacecraft on Mars over the past half century, and China landed on the Martian surface in 2021, but neither attempted a landing on either moon. The MMX mission is the first to try.
The broader competition to return material from Mars itself continues separately. Nasa’s Perseverance rover has already collected samples on Mars, but The Guardian reports its return mission was halted after a congressional vote in January 2026, following a decision by the Trump administration. China’s Tianwen-3 spacecraft is scheduled to launch around 2028 and could, according to the source, bring back Martian surface samples as early as 2031, potentially before MMX returns from the Phobos mission.
Jaxa says MMX’s findings will also inform planning for future crewed Mars expeditions.
