Review
Why Mars’s moons still confuse scientists
Mars is orbited by two small, misshapen moons that look nothing like Earth’s—Phobos and Deimos. For decades, scientists have debated whether they are captured asteroids or the remnants of a long-lost collision around Mars. One of them, Phobos, is slowly spiraling inward and will eventually break apart or crash into the planet. These tiny moons may hold big clues about Mars’s history and the chaotic early days of the solar system.
