A spacecraft has launched from Japan, setting off on a groundbreaking mission to Mars' moon Phobos. The goal? To collect and bring back a sample of moondust to Earth. If successful, this mission will achieve something that's never been done before: returning material from Mars or its moons for analysis back home.
The Mars Moons Exploration (MMX) mission, led by the Japanese Space Agency, is projected to reach its destination, Phobos, by August 2027. The primary aim is to unravel the mystery of how Mars' moons formed. Prof Sara Russell from the Natural History Museum, who is also the deputy for sample analysis on the MMX mission, expressed her enthusiasm, highlighting the unprecedented nature of this endeavor.
In the inner Solar System, there are only three moons: our own Moon and Mars' two moons, Phobos and Deimos. These Martian moons are relatively small, with Phobos measuring approximately 20 km across and Deimos about 10 km. Their odd shapes have often been likened to space potatoes. The MMX spacecraft will first study Deimos before focusing its efforts on Phobos.
One significant challenge for the mission is landing a small rover on Phobos, a feat no one has accomplished before. Russell explained the difficulty, pointing out the moon's minimal gravity and its close proximity to Mars, which has much stronger gravity. The rover's job will be to find a suitable landing site for the MMX spacecraft, which will later land on Phobos itself.
Once the spacecraft is on the surface, it will use a robotic arm and two samplers to gather moondust. This material, though weighing just 10 grams, will be carefully packed into a small capsule for the return trip to Earth, expected to land in the Woomera desert of South Australia in 2031.
Dr Chrysa Avdellidou from Leicester University, who works with the Japanese mission, stressed the scientific importance of even this small amount. She remarked that each grain could provide significant insights, making every gram valuable.
Scientists are eager to discover the origins of Mars' moons. Some theories suggest a space rock collided with Mars, creating Phobos and Deimos from the debris. Others propose that the moons are captured asteroids from the outer Solar System. Russell noted that analyzing the sample's chemistry and mineral composition should quickly reveal which scenario is correct.
There's also a chance of an unexpected bonus. Russell mentioned that because Phobos is so close to Mars, impacts on the Martian surface might embed grains into Phobos. Thus, the sample could contain Martian material, providing direct information about Mars' composition and history.
Bringing Martian material back to Earth has long been a goal for space scientists. The Nasa Perseverance rover, which has been active on Mars since 2021, has been collecting samples for a future retrieval plan. However, the planned Mars Sample Return mission, a collaboration between NASA and ESA, has been canceled due to funding cuts by the US Congress.
Meanwhile, China is preparing its own mission to Mars, set to launch in 2028 with the goal of returning samples by 2031. Though we have Martian meteorites on Earth, these are contaminated upon arrival, mixing with Earthly elements. A pristine sample from Mars and its moons is still a highly sought-after goal for scientists.
