Japan launches first mission to bring Martian moon samples back to Earth

Samples collected from Phobos are due to land in South Australia's Woomera when the five-year MMX mission ends

By LineZotpaper

Published19 October 2026

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Japan has launched an international space mission to collect rock and sand from Phobos, the larger of Mars's two moons, in a five-year voyage that will culminate with the samples parachuting to Earth at Woomera in remote South Australia.

Japan's space agency JAXA launched the Martian Moons eXploration (MMX) spacecraft this morning from the Tanegashima Space Centre. It is the first mission of its kind to collect samples from a Martian moon.

The spacecraft will take about a year to reach Mars, arriving in 2027, where it will enter a quasi-satellite orbit around Phobos. It will then attempt two "soft landings," deploying a rover to the moon's surface to collect at least 10 grams of sand from about two centimetres below the surface.

Yaji Kentaro, from the MMX project team, said low gravity made the task difficult. "Because the surface gravity is so low, there were concerns that the rover might tip over upon landing," he said. The rover's landing legs have been designed with special features to ensure a stable landing. The spacecraft will also photograph Mars and Phobos as it approaches.

Researchers hope the samples will reveal how Mars and its moons formed and provide new insights into the origin of water and organic materials on the red planet. The mission team describes Phobos as a "potato-shaped" moon that has not undergone the same geological evolution as planets, so it should preserve evidence of Mars's early development. Two conflicting theories exist: the moons may have formed after a huge collision with Mars, or they may be asteroids pulled into Mars's gravity.

"While Earth is home to many living organisms, including humans like us, the question remains where the water and organic matter necessary for life came from," Mr Yaji said. "It is hoped that the answer to this question may be hidden within the samples."

After collecting samples, the spacecraft will observe Mars's other moon, Deimos, before beginning its year-long journey back to Earth. The re-entry capsule is expected to land in Woomera, South Australia, where the samples will be retrieved. Australia's ambassador to Japan, Andrew Shearer, joined ambassadors from France, Germany and the United States, along with representatives including NASA, to watch the launch.

Analysis

Why This Matters

This is the first sample return mission targeting a Martian moon, and the analysis could help settle conflicting theories about how Mars and its moons formed.
The mission may clarify where water and organic materials on Mars came from, with implications for the question of whether life could once have developed there.
It is a stepping stone for potential human exploration of Mars, and gives Australia a direct role in the final retrieval of extraterrestrial samples.

Background

Mars's surface is a cold desert with a thin atmosphere, but traces of water suggest the planet once had a similar environment to Earth. Phobos, the larger of Mars's two moons, is considered primitive because it has not undergone the geological evolution of planets, so it should preserve evidence of the early development of Mars. The MMX mission is led by Japan's space agency, with international participation and diplomatic support from France, Germany, the United States and Australia.

Key Perspectives

JAXA mission team: The team sees the moon's very weak gravity as the central engineering challenge, designing special landing legs to stop the rover tipping over, and says the samples may hold answers about the origin of water and organic matter needed for life. International partners: Representatives from NASA and ambassadors from France, Germany, Australia and the United States attended the launch, underlining the collaborative nature of the mission. Australia's role comes at the end, when the return capsule lands at Woomera. Skeptics: No external critics are cited in the reporting. The risks are acknowledged within the mission itself: two soft landings on a body with extremely low gravity, a five-year timeline and the challenge of collecting enough material. Success depends on every stage of the long flight.

What to Watch

The spacecraft's arrival at Mars in 2027 and its entry into quasi-satellite orbit around Phobos.
The two planned soft landings and whether the rover collects at least 10 grams of sand from the moon's surface.
The images MMX sends back of Mars and Phobos as it gets closer to its destination.
Whether the returned samples support the collision theory or the captured-asteroid theory of how Mars's moons formed.

Sources

Japan launches first mission to collect samples from Martian moon · Just In

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12 claims in this story checked against 1 source: 10 supported.

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SupportedJapan has launched the first mission to bring samples from a Martian moon back to EarthJust In: “Japan launches first mission to collect samples from Martian moon.”
Partly supportedSamples from Phobos are due to land in Woomera, South Australia, parachuting to Earth when the five-year MMX mission endsJust In: “The capsule is expected to land in Woomera, in remote South Australia, where the sand sample will be retrieved.”
SupportedYaji Kentaro said: 'Because the surface gravity is so low, there were concerns that the rover might tip over upon landing.'Just In: “Because the surface gravity is so low, there were concerns that the rover might tip over upon landing.”
SupportedMr Yaji said: 'While Earth is home to many living organisms, including humans like us, the question remains where the water and organic matter necessary for life came from.'Just In: “While Earth is home to many living organisms, including humans like us, the question remains where the water and organic matter necessary for life came from.”
SupportedJAXA launched the MMX spacecraft this morning from the Tanegashima Space CentreJust In: “A rocket carrying the Martian Moons eXploration (MMX) spacecraft was launched this morning from Japan's Tanegashima Space Centre.”
SupportedThe spacecraft will take about a year to reach Mars, arriving in 2027, and enter a quasi-satellite orbit around PhobosJust In: “The MMX spacecraft will spend a year travelling to the Martian sphere, where it is set to arrive in 2027. It will then enter a quasi-satellite orbit around the moon, Phobos.”
SupportedThe mission will attempt two soft landings and collect at least 10 grams of sand from about two centimetres below the surface of PhobosJust In: “attempt two "soft landings". That is when a rover will be sent to the surface of Phobos to collect at least 10 grams of sand, at a depth of about 2 centimetres.”
SupportedAfter collecting samples, the spacecraft will observe Deimos before beginning its year-long journey back to EarthJust In: “After completing the sample collections on Phobos, the spacecraft will then observe Mars's second moon, Deimos, before beginning its year-long journey back to Earth.”
Partly supportedAustralia's ambassador to Japan, Andrew Shearer, joined ambassadors from France, Germany and the United States, along with NASA representatives, to watch the launchJust In: “France and Germany's ambassadors were also there, along with the deputy ambassador from the United States and representatives from other space agencies, including NASA.”
SupportedThe MMX project team says Phobos is a 'potato-shaped' moon that has not undergone the same geological evolution as planets, so it should preserve evidence of Mars's early developmentJust In: “The MMX project team said Phobos, the "potato-shaped" moon orbiting Mars, had not undergone the same geologic evolution of planets and so should have preserved evidence of the early development of Mars.”
SupportedThere are conflicting theories that Mars's moons formed after a huge collision with Mars or were asteroids pulled into Mars's gravityJust In: “There are conflicting theories about how Mars's moons formed. The first is that there was a huge collision with Mars; the second is that they started as asteroids and were pulled into Mars's gravity.”
SupportedResearchers hope the samples will reveal how Mars and its moons formed and provide new insights into the origin of water and organic materials on MarsJust In: “It is hoped the mission will provide new insights about the origin of water and organic materials on Mars”