Japan Phobos Mission Launches to Grab Mars Moon Dust

The Japan Phobos mission is officially on its way. According to Euronews, Japan has launched a spacecraft on a first-of-its-kind journey to Mars, where it will try to land on the moon Phobos and bring a piece of it back to Earth.

Liftoff day

The Japan Aerospace Exploration Agency launched the Martian Moons eXploration probe, called MMX, before dawn on Tuesday from Tanegashima Island. JAXA says the H3 rocket lifted off at four forty-one in the morning Japan time, and the spacecraft separated about seventy-one minutes later and entered its planned orbit, according to the JAXA press release.

Flight controllers burst into applause, shaking hands and hugging after officials declared success. Ars Technica notes the rocket flew in a new souped-up setup, with four strap-on boosters and a longer payload shroud, built for Japan's heaviest and most ambitious interplanetary mission yet.

Why Phobos is such a big deal

NASA has landed nine spacecraft on Mars over the past fifty years, and China touched down in 2021. Yet nobody has ever landed on Phobos or its smaller partner Deimos, and nobody has brought back samples from Mars or its moons. Phobos is a lumpy, potato-shaped rock about twenty-two kilometres across.

The mission costs five hundred and seventy-eight million dollars and is backed by five space agencies. Japan is putting in about three hundred and fifty million, NASA about eighty-seven million, with France, Germany and the European Space Agency chipping in the rest.

Meet Idefix, the tiny rover

The coolest part for many fans is Idefix, a French-German rover named after the white terrier from the Asterix comics. It is no bigger than a microwave oven and will drop onto Phobos on its own, bouncing for several minutes in the moon's extremely low gravity before it settles.

Idefix will crawl at a glacial one millimetre per second for about one hundred days. Its job is to be a scout for safety, helping Japanese controllers avoid powdery soil and rough terrain before the main lander touches down in late 2028 or 2029. The lander will spend only two hours on the surface, drilling and vacuuming up at least ten grams of material.

The big question: where did Mars' moons come from?

Scientists want to know whether Phobos and Deimos formed after an ancient crash between Mars and a space rock, or whether they are stray asteroids caught by Mars' gravity. Either way, researchers expect traces of Mars on Phobos, which makes the samples an irresistible two-for-one.

The findings could also help explain how planets and moons form, and they will shape future Mars missions, including crewed ones, according to NASA's acting planetary science director Lindsay Hays quoted by Euronews.

A risky road, and a space race

This is a dangerous trip. Russia failed in all three of its Phobos attempts, and Japan's only earlier Mars mission failed to enter orbit around the red planet. The moons' names do not help: Phobos is Greek for fear and Deimos means dread. Japan does have an edge, having already completed two asteroid sample returns.

The spacecraft should reach Mars around late next summer, and the samples are due to land in the Australian desert in twenty thirty-one. China plans its own Mars sample return launch in twenty twenty-eight and is also aiming for twenty thirty-one, so the two could end up neck and neck. For more on the science beat, see our science coverage.

Why should you care? Sample returns let scientists test rocks in labs on Earth with instruments far more powerful than anything a robot can carry. Japan already did this with asteroids, and those samples reshaped ideas about how the early Solar System worked. A piece of Phobos could do the same for the Mars neighbourhood, and it is a rare moment when a dozen countries are cheering for the same tiny rock.

For now, the next big milestone is a long cruise through space. If everything works, a pinch of dust from another world will be in labs by the start of the next decade, and the whole planet will get to find out where Mars' strange little moons really came from.