In some ways, Mars looks like a barren desert on Earth, except that it is much colder. Its surface is covered with a rust colored dust. Mars has polar ice caps made of frozen carbon dioxide (dry ice) and water. Since Mars has an atmosphere, winds can erode surface features and kick up gigantic dust storms. The tilt of Mars’ axis is similar to that of the Earth, so Mars has 4 seasons. However, each season is twice as long as on Earth! Olympus Mons and Valles Marineris are two of the most fantastic features in the Solar System. Olympus Mons is an enormous volcano that is nearly 70,000 feet tall. That is more than twice as high as a typical airliner flies! Valles Marineris is a 2500 mile long canyon, making our Grand Canyon look incredibly small. The Grand Canyon was formed by water erosion, but Valles Marineris was most likely created by faulting of the Martian crust. Olympus Mons with Wisconsin overlain for scale. Valles Marineris with the United States overlain for scale.