Mars received its name from the god of war in Roman mythology, Mars. Because the planet appeared red, it reminded the Romans of blood shed during battle. The ancient Greeks also named the planet after their god of war, Ares.
Ancient societies often used the color of a planet to determine its name. The red in the planet for which Mars is named comes from the iron content of the surface. Scientists named the largest volcano on the planet Olympus Mons after Mount Olympus in Roman mythology. The moons surrounding the planet were also named after the sons of the Greek god Ares, Phobos and Deimos, which mean "fear"and "panic" respectively.