A Japanese spacecraft embarked on a five-year mission to collect soil samples from Phobos, one of Mars’s two moons, aiming to deepen scientific understanding of the Martian system and the origins of the solar system. The Martian Moons eXploration (MMX) mission launched at 8:40 p.m. from the Tanegashima Space Centre in southern Japan, beginning its journey spanning approximately 300 million miles.

Phobos, although the larger of Mars’s moons, measures just about 12 miles across. MMX is tasked with obtaining at least 10 grams of dust and rock—roughly the weight of an AAA battery—from the moon’s surface. This would mark the first time samples have been collected directly from Mars’s moons. The mission is expected to provide critical data that could resolve a longstanding scientific debate over Phobos’s origin, which remains uncertain. Researchers seek to determine whether Phobos is a captured asteroid or debris from a past impact involving Mars.

The spacecraft’s design includes three modules: a propulsion unit to travel to Mars, an exploration module to gather samples, and a return module to bring the material back to Earth. MMX is scheduled to arrive in orbit around Phobos in August 2025. In 2029, a microwave oven-sized rover will be deployed to explore the moon’s surface for approximately 100 days. After identifying a suitable sampling location, the exploration module will descend, spend around two and a half hours collecting material, and eventually return to Earth in 2031.

In addition to exploring Phobos directly, MMX will conduct remote studies of Deimos, the smaller Martian moon, to complement its findings. The Japan Aerospace Exploration Agency (JAXA), which is leading the mission, highlights that this endeavor aims not only to shed light on the processes that shaped the Martian environment but also to contribute to broader questions about the solar system’s formation and the emergence of life.

The MMX mission, with an estimated cost of £262 million, represents a significant investment in deep-space exploration and is positioned as a stepping stone for future scientific ventures beyond Earth’s immediate neighborhood.