Tokyo: Japan is preparing to launch an ambitious mission to Phobos, one of Mars’ two moons, in an effort to collect samples that could answer longstanding questions about the origins of the Martian system.
The Japan Aerospace Exploration Agency’s Martian Moons Exploration mission, known as MMX, is scheduled to launch from the Tanegashima Space Centre on 20 October 2026. If successful, it will become the first mission to bring samples from a Martian moon back to Earth.
MMX is expected to take about a year to reach Mars, followed by around three years of exploration before beginning its return journey. Scientists expect the samples to arrive on Earth in 2031.
A central objective is to determine how Phobos and Deimos formed. One theory suggests the moons were created from material thrown into space after a massive impact on Mars. Another proposes that they were asteroids captured by Mars’ gravity.
Phobos has characteristics resembling some water and carbon rich asteroids, while its nearly circular orbit around Mars could support an origin linked to the planet. Samples collected directly from its surface could provide evidence to help resolve the debate.
The mission also presents significant engineering challenges. Phobos has a radius of only about 11 kilometres and very weak gravity, making landing and taking off particularly difficult. MMX will rely heavily on autonomous navigation, as communication between Earth and the spacecraft can take up to 20 minutes.
A rover developed jointly by French and German space agencies will first explore the surface for about 100 days, helping identify a suitable landing area. MMX will then use a robotic arm and other equipment to collect material from the moon.
Some of the samples could also contain material originating from Mars, blasted from the planet by meteorite impacts over millions of years.
The mission, costing about USD 345 million, is also designed to test technologies that could support future sample return missions and deeper exploration of Mars.
The mission marks Japan’s return to Mars exploration after 28 years and could provide scientists with valuable material for understanding the history and formation of the Martian system.
