Roman god of war, also the name of the bright red planet, late 14c., from Latin Mars (stem *Mawort-), the Roman god of war, of unknown origin, apparently from earlier Mavors, related to Oscan Mamers. According to Watkins the Latin word is from *Mawort- "name of an Italic deity who became the god of war at Rome ...." He also had agricultural attributes, and might ultimately have been a Spring-Dionysus. The planet was so named by the Romans, no doubt for its blood-like color. The Greeks also called the planet Pyroeis "the fiery."
The fourth planet from the Sun and the third smallest in the solar system, with a diameter about half that of Earth. Mars is the last of the terrestrial or inner planets and has notable similarities to Earth, including polar ice caps and a tilted axis that gives it seasons. However, it is significantly less dense than Earth and has no magnetic field, suggesting that it lacks a metallic core, and its atmosphere, made up mostly of carbon dioxide, is much thinner than Earth's. Mars has no surface water apart from a layer of permanent ice that underlies the seasonally changing caps of frozen carbon dioxide at its poles; there is, however, clear evidence of earlier water flows in the form of channels, outwashes, and canyons. Other surface features include numerous craters, especially in the southern hemisphere, along with very large volcanoes and extensive windblown dunes. Mar's reddish color is due to the abundance of hematite in its surface rocks. Its two small, irregular moons, Phobos and Deimos, may be asteroids captured earlier by gravitational attraction. See Table at solar system.
The Roman name of Ares, the Greek and Roman god of war.
Note: The fourth planet from the sun (the Earth is third) is named Mars, possibly because its red color is reminiscent of blood.
Note: The month of March is named after Mars.
Note: Smaller than the Earth, Mars has polar ice caps and a surface that includes red sands.
Note: The Viking space mission, which placed landers on the surface of Mars, did not discover any signs of life.
Note: Mars has been, and remains, the focus of space research by NASA. Voyages to Mars, including multiple landings, are scheduled through the first decade of the twenty-first century.