Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the “Red Planet”, as the iron oxide prevalent on its surface gives it a reddish appearance.
Mars is a terrestrial planet with a thin atmosphere, having surface features reminiscent both of the impact craters of the Moon and the volcanoes, valleys, deserts, and polar ice caps of Earth. The rotational period and seasonal cycles of Mars are likewise similar to those of Earth. Mars is the site of Olympus Mons , the highest known mountain within the Solar System at over 14 miles tall, and of Valles Marineris, the largest canyon (the gash in the middle of the image.)
Mars has two moons, Phobos and Deimos, which are small and irregularly shaped. (From Wikipedia)
The image is from the Viking 1 orbiter.