Japan has taken a major step towards answering one of planetary science’s long-standing questions: how did the two moons of Mars come into existence? The country’s Martian Moons eXploration (MMX) mission is now on its journey towards the Red Planet, with an ambitious goal of collecting material from Phobos and returning it to Earth for detailed laboratory analysis.
The mission could open a new chapter in space exploration. By examining actual samples from a Martian moon, scientists hope to uncover clues about the formation of Mars’ moons, the planet’s early history and the evolution of the solar system.
Unlike missions that study distant worlds only through photographs and remote measurements, MMX is designed to bring physical material home. If successful, it will become the first mission to return samples from the Martian system to Earth.
Japan’s MMX Space Mission Begins Its Journey to Mars
The MMX spacecraft was launched aboard Japan’s H3 rocket from the Tanegashima Space Center. Following its departure from Earth, the spacecraft separated from the rocket and began its journey towards the Martian system.
The mission is led by the Japan Aerospace Exploration Agency (JAXA), with contributions from international partners, including NASA, the European Space Agency (ESA), France’s space agency CNES and the German Aerospace Center (DLR).
The spacecraft is expected to reach the vicinity of Mars in 2027. Its journey and operations around the Martian moons will form part of a mission lasting approximately five years, with the return of samples planned for 2031.
Why the MMX Mission Matters
Mars has been studied extensively by orbiters, landers and rovers. However, its two small moons, Phobos and Deimos, remain far less understood.
Scientists still do not know exactly how these moons formed. One leading explanation suggests that they may be asteroids captured by Mars’ gravity. Another possibility is that they formed from debris thrown into space after a massive impact on Mars.
MMX is designed to collect scientific evidence that could help researchers distinguish between these explanations.
Phobos: The Mysterious Moon at the Centre of the Mission
Phobos is the larger and closer of Mars’ two moons. It is an irregularly shaped body measuring approximately 27 kilometres across at its longest dimension, making it a very different environment from Earth’s Moon.
Its unusual shape, low gravity and uncertain origin make it an important target for planetary scientists.
The MMX spacecraft will study Phobos in detail, examining its surface, composition and physical characteristics. Researchers will also observe Deimos from a distance to improve their understanding of the wider Martian moon system.
Could Phobos Reveal the Origins of Mars’ Moons?
The origin of Phobos remains one of the major unanswered questions in planetary science.
If it is a captured asteroid, samples could reveal information about the population of small bodies that existed during the early history of the solar system. Such findings may also help scientists investigate how water-bearing materials were transported between different regions of the solar system.
If Phobos instead formed from debris created by an enormous impact on Mars, its material could contain evidence about the planet’s ancient surface and geological history.
Laboratory analysis of returned samples could help researchers determine which explanation best fits the evidence.
What Scientists Hope to Learn About Early Mars
The samples may contain a mixture of material from different sources. Some particles could have originated from Phobos itself, while others may have arrived through impacts by asteroids or material ejected from Mars.
Studying these components could provide a more detailed picture of the conditions that existed billions of years ago.
However, the exact composition of the samples and the conclusions scientists will be able to draw remain uncertain until the material is collected and analysed.
How Will the MMX Mission Collect Samples?
Reaching Phobos is only the first stage of the mission. The spacecraft must navigate the complex gravitational environment around Mars, examine potential landing locations and collect material without losing contact with Earth.
The mission combines remote observations, robotic surface exploration and specialised sampling equipment.
Step 1: Travel to the Martian System
The spacecraft is expected to reach Mars in 2027, approximately one year after launch.
Instead of relying on a conventional orbit directly around Phobos, MMX will use a carefully designed trajectory near the moon. Phobos is small and its gravitational influence is weak, making stable orbital operations particularly challenging.
Step 2: Study Phobos and Deimos
Once it reaches the Martian system, MMX will use cameras, spectrometers and other scientific instruments to examine the moons.
These instruments will help map the surface, identify promising sampling locations and measure the physical and chemical characteristics of the material.
The observations will also contribute to a better understanding of Deimos, the smaller and more distant Martian moon.
Step 3: Deploy the IDEFIX Rover
A small rover named IDEFIX, developed through French-German cooperation, will explore the surface of Phobos.
Its observations will help scientists understand the terrain and assess how a lander might operate in the moon’s extremely low-gravity environment.
The rover is an important part of the mission because even a seemingly small landing manoeuvre can be difficult on a body where gravity is so weak.
Step 4: Collect Material From Phobos
The MMX mission aims to collect at least 10 grams of material from Phobos.
Its sampling system includes equipment designed to gather surface particles and a coring mechanism that can collect material from below the immediate surface.
These techniques are intended to provide researchers with physical samples suitable for detailed laboratory investigation.
The sampling operation is one of the mission’s most demanding stages. The spacecraft must approach the surface, collect enough material, secure the samples and depart safely.
Step 5: Return the Samples to Earth
After completing its observations and sampling operations, MMX is scheduled to begin its return journey.
The mission currently aims to bring the collected material back to Earth in 2031. Once recovered, the samples can be examined using laboratory instruments that would be impossible to send aboard a spacecraft.
This analysis could reveal chemical signatures, mineral structures and other details that remote observations alone cannot establish with the same precision.
International Cooperation Behind Japan’s Mars Moon Mission
Although JAXA leads the project, MMX relies on expertise from several countries and space agencies.
NASA contributes scientific and technical capabilities, while ESA provides support that includes deep-space communications. France and Germany have collaborated on the IDEFIX rover and other mission components.
Each partner brings specialised knowledge in areas such as spacecraft operations, scientific instruments, surface exploration and sample analysis.
Why Collaboration Is Essential for Deep-Space Exploration
A mission to collect samples from a small moon around another planet involves numerous technical challenges.
The spacecraft must travel across interplanetary distances, operate reliably with communication delays, navigate weak gravity and conduct a carefully controlled sampling operation.
International cooperation allows research teams to combine expertise and share scientific opportunities. It also helps ensure that the returned material can be studied by specialists across multiple research institutions.
What Makes a Sample-Return Mission Different?
Spacecraft can learn a great deal about distant objects by measuring reflected light, detecting radiation and photographing their surfaces. However, these methods cannot answer every scientific question.
Physical samples provide researchers with a different level of access to a celestial body’s history.
Laboratory Analysis Can Reveal Hidden Details
Scientists can examine samples using advanced instruments to identify minerals, measure chemical compositions and investigate microscopic structures.
They can also compare the results with meteorites, asteroid samples and material collected by other space missions.
These comparisons may help establish whether Phobos resembles primitive asteroids or contains material linked to Mars itself.
The scientific value of MMX will therefore extend beyond the mission’s immediate destination. Its findings could improve our understanding of how small celestial bodies form and evolve.
What Could the Mission Mean for Future Mars Exploration?
The MMX mission is primarily designed to investigate the Martian moons and return samples, but its technologies and scientific findings could also support future exploration.
Learning more about the environment around Mars may help researchers understand the challenges involved in operating spacecraft near small planetary bodies.
The mission will also test systems for navigation, communications, surface sampling and the return of extraterrestrial material to Earth.
Could MMX Help Scientists Understand the Conditions for Life?
The mission is not a direct search for life on Phobos. Its main scientific goals concern the origins of Mars’ moons, the evolution of the Martian system and the movement of material through the early solar system.
Nevertheless, understanding how Mars and its surrounding environment evolved could contribute to broader research into planetary habitability.
Scientists are particularly interested in how water and other important materials moved through the early solar system. MMX may provide useful evidence for investigating these processes, although it cannot by itself resolve every question about the origin of life.
What Are the Biggest Risks Facing the MMX Mission?
Even after a successful launch, a deep-space mission faces years of technical challenges.
The spacecraft must complete its interplanetary journey, enter the planned operating environment, study Phobos, deploy its rover and collect material. Each stage requires precise navigation and reliable equipment.
The moon’s weak gravity and irregular surface add further complications. A sampling manoeuvre must be carefully controlled to avoid an unsuccessful contact with the surface or difficulties during departure.
Why Every Stage Will Matter
A problem during one phase could affect later operations. However, even if some mission objectives prove difficult to achieve, observations and measurements collected along the way could still produce valuable scientific results.
The full success of MMX will ultimately depend on whether the spacecraft can complete its key objectives and return usable samples to Earth.
MMX Mission Timeline: From Launch to Earth Return
The mission is planned to unfold over several years.
- 2026: Launch from Japan and departure towards the Martian system.
- 2027: Expected arrival in the vicinity of Mars, followed by operations around its moons.
- 2027 onward: Detailed observations of Phobos and Deimos, including surface studies and preparation for sampling.
- Around 2030: Planned completion of major exploration and sample-collection activities, subject to mission operations.
- 2031: Target year for the return of samples to Earth.
These are planned milestones rather than guaranteed completion dates. Space missions can change schedules when technical, navigational or operational challenges arise.
Conclusion: A New Opportunity to Understand Mars’ Mysterious Moons
Japan’s MMX mission represents an important effort to investigate one of the least understood parts of the Martian system.
By combining detailed observations, robotic surface exploration and sample-return technology, the mission aims to provide evidence that could finally clarify how Phobos and Deimos formed.
The planned return of material in 2031 will be a particularly important milestone. If successful, the samples could give scientists a rare opportunity to examine a Martian moon directly in laboratories on Earth.
The journey is long, and significant challenges remain. But the knowledge gained from MMX could improve our understanding of Mars, the formation of planetary systems and the history of material moving through our cosmic neighbourhood.
According To MMX