The two moons are very small but very interesting and relatively near-Earth objects of study of Planetary Sciences. There are obviously of the gravity of the planet Mars captured small bodies in the asteroid belt. Their diameters are equal to 15 km for Deimos, the smaller, and 25 km for Phobos, the larger of the two satellites. They consist of a relatively loose mixture of silicate rocks and rock dust. Phobos is so light that he either be really porous, or must, however, are partly composed of water, even if such a date to at least on the surface could not be demonstrated. The orbits of the moons are nearly circular, and while Deimos orbits the planet in greater distance races Phobos in less than 10,000 km height in just seven hours on Mars. This is by far the smallest radius of the orbit of a satellite around its planet in the entire solar system. Phobos moves to the Roche’schen so designated limit, below which is being torn apart by the gravity of a moon of the planet and as a ringfrom boulders and dust around the mother’s body lays in the disintegration or crash and embarks on the planet. Rail calculations show that this fate of the satellite in the astronomical times threatens relatively short time of the next approximately 100 million years. Phobos is the only known moon, which rotates because of the short distance to the planet’s surface so rapidly that it overtakes the self-rotation of the planet and goes down on a seemingly retrograde path to the west and the east. Your own gravitational pull of Martian moons is very low and is hardly enough to protect the surface from erosion by particle radiation from the solar wind. In particular, therefore, Phobos moves in its orbit around Mars dust flag behind him. A person would weigh on each of the moons only a few grams