Mars has a thin atmosphere composed mostly of carbon dioxide, with very little oxygen. This results in extreme temperature variations, ranging from about -195°F (-125°C) at the poles during winter to 70°F (20°C) at the equator during summer. Dust storms can occur, sometimes covering the entire planet and affecting temperatures. The planet experiences seasons similar to Earth due to its axial tilt. However, Martian seasons last about twice as long because Mars takes nearly 687 Earth days to orbit the Sun. The presence of ice caps at the poles indicates that water exists in frozen form, influencing the climate and potential for past life.