Mars has one moon, Phrodeimos, which is small sized moon. It used to be two captured asteroids, Phobos and Deimos, until the humans had fused them and a few other asteroids together to stablize the fluctuating axis. The new moon was placed half way through the distance of Phobos and Deimos. Phrodeimos makes a complete orbit around Mars every 30.132424 days.