By Sumayya

TORONTO – Japan has sent a spacecraft on a five-year round trip to a strange little moon of Mars, and if everything goes well, it will bring a piece of it back home.

“It’s just a whole new level of challenge and excitement,” said Paul Delaney, an old professor of astronomy at York University in Toronto. The Martian Moons eXploration mission, or MMX, flew into space on a rocket from Japan’s Tanegashima Space Center before dawn on Tuesday [20 October 2026]. Its target is Phobos, the larger of the two small moons circling around Mars.

“The Japanese have a habit of doing exciting space trips, in my opinion, and this one is absolutely no exception,” Delaney said. “MMX is trying to do something which nobody has done before.” While the Japan Aerospace Exploration Agency (JAXA) had twice before brought back pieces from space rocks called asteroids, no space office has ever brought back material from a moon other than our own.

Phobos is only about 22 kilometers wide, and Deimos, Mars’ other moon, is about half that size. By comparison, our own moon is more than 3,000 kilometers wide. “Really, really tiny,” Delaney said of the Martian moons, but they hold a big mystery. “The simple question is: Where did the moons of Mars come from?” Delaney asked. One theory is that something crashed into Mars long ago and blasted broken pieces into space, which clumped together into these moons.

Scientists believe our own moon was made in a similar way. The other theory is that Phobos and Deimos are just space rocks that floated too close and got caught by the planet’s gravity pull. “Are they captured asteroids?” Delaney asked. “It sounds like a simple enough question, but the answers actually speak to the earliest moments of the solar system and how planets were made.” He expects the answer to come fast once the sample of moon dust reaches a lab on Earth. “That’ll be pretty obvious the moment we start looking closely at those few grams.”

Japan is leading this space trip with help from NASA and European partners. The spacecraft should reach Mars in August, about 10 months from now, and spend more than a year studying Phobos from above. It will then drop off a small French-German driving robot to scout the ground. After that, the main spacecraft will land, grab at least 10 grams of moon dust, and then head back to Earth. A small capsule holding the sample is planned to drop by parachute into the Australian desert in 2031.

Why bring that dust all the way back to Earth instead of having the spacecraft check it out? “We’ve got massive laboratories with far more advanced tools to test the sample,” says Delaney, who calls sample return trips the ultimate prizes of solar system exploration.

This launch comes at a time when a plan by NASA to bring back rocks from the surface of Mars has stopped. The Perseverance driving robot spent years gathering samples, but the U.S. Congress cut money this year for the trip to go get them after its costs grew too big.

“Will those samples that Perseverance collected ever see the laboratories here on Earth? Probably, but who knows when?” Delaney says. As for the sample from Phobos, he thinks it could hold some surprises, like possible signs of the chemical building blocks of life.

“We’ve often found organic molecules in the strangest of places, the most unlikely places in our solar system and in the universe,” Delaney says. There is a long way to go, and plenty of things could go wrong, but Delaney is cheering for it. “This really is a very exciting space trip,” he says. “A tip of the hat to them if they can pull it off.”