Mars has two, tiny asteroid-sized moons called Phobos and Deimos. Phobos orbits the planet at such a low altitude that it’s going to eventually be torn apart by the gravity of Mars.

It is believed that early in its history, Mars was much more like Earth. Both rovers, Spirit and Opportunity, provided evidence that liquid water once existed on the surface of Mars. It is highly probable that at some time in the past there were rivers, large lakes or even oceans on Mars. Similar to earth, Mars has ice caps at both its north and south poles.