Japan to launch historic mission to Mars’ moons, bring back first-ever soil samples

Japan is launching a five-year mission to bring back something no one's ever collected before, soil from a moon of Mars. The spacecraft is headed for Phobos, one of two small potato-shaped moons orbiting the red planet. It's expected to arrive at Mars next August, then study Phobos before landing to collect at least 10 grams of soil. Scientists hope those samples will finally answer a big question. Did Mars capture an asteroid, or did the moon form from debris after a massive collision? These are asteroids that would have been roaming the solar system that were maybe knocked or pulled too close to Mars and then captured into Mars's gravity and then over time gradually became into a more stable orbit. The other leading theory is that they are the leftovers from a disk of debris that was formed by a giant impact into Mars. And there are some nuances on both of those theories, but it's one of the remarkable things that we've not been able to answer that question yet. NASA is helping with the mission, along with European partners, and if all goes to plan, those samples will be back on Earth in 2031.