The names of the moons that orbit Mars are Phobos and Deimos. American astronomer Asaph Hall discovered the two moons in 1877. Both Phobos and Deimos may actually be captured asteroids because their surfaces are made of the same substances that make up the asteroids in the outer asteroid belt.
Named for fear and panic, the two mythical horses that pulled the chariot of Mars, the Roman god of war, these two moons orbit relatively close to Mars: Phobos' orbit is 3,000 miles above the surface of the planet, and Deimos is not much farther out. Neither Phobos nor Deimos look like typical moons. They are not spherical like the larger satellites or moons of other planets in the solar system. Being smaller in size and irregular in shape, Phobos and Deimos are considered minor satellites; major satellites such as Earth's moon have more spherical shapes.