The Martian Moons Exploration mission will aim to bring back samples from Phobos
By Adam Kovac edited by Clara Moskowitz
Japan’s Martian Moons Exploration (MMX) mission lifts off on October 19, 2026.
JAXA/YouTube
Japan’s mission to collect samples from a Martian moon is off to a good start.
Launched atop an H3 rocket from Tanegashima Space Center just after 3:40 P.M. EDT on Monday, the Martian Moons Exploration (MMX) mission is a collaboration between the Japan Aerospace Exploration Agency (JAXA), NASA, the French space agency CNES and the European Space Agency (ESA).
If successful, MMX will be the first spacecraft to enter orbit around Phobos, one of Mars’s two moons. The goal is to learn more about how the mysterious, small moon first formed. One theory posits that Phobos and its companion, Deimos, are former asteroids that were captured by Mars’s gravity, while another is that they are composed of debris from an ancient, massive collision with the Red Planet.
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
The mission could also provide clues into how organic matter, or even life itself, forms on planets.
To figure this out, MMX will spend a year flying through space, and it is scheduled to arrive at Phobos in September 2027. Once there, it will observe the Martian moon from orbit to look for two suitable landing and sampling sites, one on each side of the natural satellite. Once those sites are found, the main spacecraft will release a rover, called Idefix, onto Phobos’s surface.
The rover will first sample material from Phobos’s subsurface in its onboard lab. Later the main spacecraft will land on Phobos sometime in 2030 and gather material in its return module. That module will lift off from Mars and come back to Earth with at least 10 grams of material sometime in 2031.
“Bringing samples to our most sophisticated labs here on Earth is a multiplier for discoveries, because our most precise instruments are too large, complex or sensitive to send to space,” said ESA’s MMX project scientist Elliot Sefton-Nash in a statement. “Even after the mission has been completed, future generations of scientists will study the Phobos samples with even more advanced instruments—samples brought to Earth are the gift that keeps on giving.”
Subscribe to Support Independent Journalism
Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.
When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.
Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber