Mars
Half the size of Earth, Mars is known as the "Red Planet" because of the iron oxide contained in its crust. Mars' relief presents a surprising variety of structures, including canyons, high mountains, and volcanoes. Mars has a very thin atmosphere, composed mainly of carbon dioxide. Water is also present on Mars. Signs of erosion on the surface of the planet suggest that liquid water once existed on Mars. Mars is a good candidate for human settlement and is the most closely studied planet in the solar system today.
