The simple reason behind Mars’s reddish appearance is the layer of iron oxide dust covering the planet’s surface. Fine particles of various oxides of iron (hematite) and trace amounts of some elements like chlorine and sulfur on the Mar’s surface is the main reason for its reddish color. read more
Mars seems to be a dead world. It is dry, wind-blown, and covered with iron oxide dust. That dust is what gives Mars its reddish appearance. read more