The orbital periods of the two irregularly shaped moons of Mars, Phobos and Deimos, are 7.66 hours for Phobos, and 30.35 hours for Deimos. Their semi axis's length is 9,377 km for Phobos, and 23,460 km for Deimos. Both of this moons are more of an asteroids than moons, they pretty much have all the characteristics of asteroids, but they have been trapped by the gravitational pull of Mars, so they behave like moons.