JAXA Launches MMX Mission to Uncover Origins of Martian Moons
Japan's space agency JAXA launched its Martian Moons Exploration spacecraft on October 19 to bring back samples from Phobos, Mars's larger moon, by 2031, aiming to settle how the moons formed.
Newsnibs Staff
- 2026-10-24
- Updated 4:29 PM UTC
(Tanegashima, Japan)
Japan's space agency, JAXA, launched its Martian Moons Exploration (MMX) spacecraft on October 19 from the Tanegashima Space Center in Kagoshima prefecture. The mission is described as the world's first round-trip sample-return mission to Mars. It aims to bring about 10 grams of material from the surface of Phobos, the larger of Mars's two moons, back to Earth in 2031.
NASA and the European Space Agency helped build the mission. Its main purpose is to work out where Phobos and Deimos came from. The two small moons were discovered in 1877. Phobos is about 26 kilometers long and Deimos about 16 kilometers.
Scientists have three main ideas about their origin. The moons could be captured asteroids, though their circular orbits around Mars's equator are hard to square with that. They could have formed from debris after a massive impact on Mars, much as Earth's moon is thought to have formed. Or they could be the pieces of a single moon that broke apart.
The probe will travel about 225 million kilometers (140 million miles) and is scheduled to reach Mars in August 2027. There it will settle into a quasi-satellite orbit around Phobos and map its surface. The plan calls for two landings on Phobos.
A mini-rover named Idefix goes down first. France's National Center for Space Studies (CNES) and the German Aerospace Center (DLR) built it together, and it will measure the surface's temperature and mineralogy. Phobos's gravity is about one-thousandth of Earth's, so the rover will drift down at roughly walking speed. On the surface, Idefix will weigh about 15 grams.
The main MMX lander follows. It will gather rocky material with a drill and a Pneumatic Sampler, or P-Sampler, which Honeybee Robotics built for NASA. After collecting its samples, the probe will fly past Deimos several times between late 2028 and early 2029, then head home. In 2031 it will release the samples in a 60-centimeter container that will likely land in Australia.
The mission will also study the Martian atmosphere. Its samples could include preserved material from Mars itself, which could help cover a scientific gap left by the recent failure of NASA's MAVEN spacecraft.
No one has managed this before. The Soviet Union's Phobos 1 and Phobos 2 and the joint Russian-Chinese Phobos-Grunt mission all failed.
Photo by SpaceX on Unsplash
