The Universe Made Simple/The Solar System/Mars
Mars is the fourth planet from the Sun and is referred to as the red planet. Mars has half the diameter of the Earth. On the surface there are signs of ancient floods. The average temperature on Mars’ surface is negative 55° C but there are seasons and weather.
Astronomers have proof of permanent polar ice caps on Mars. The surface is very old and cratered but there are young valleys, ridges and plains. There is evidence of erosion on the surface due to some type of fluid. However the surface of Mars is very cold with very strong winds and vast dust storms. These dust storms have been known to engulf the entire planet for months. The atmosphere on Mars is too thin for liquid water to exist for long on the surface. The atmosphere consists of 95% carbon dioxide, 3% nitrogen and 2% argon. The magnetic fields are large but not global. They are probably remnants of a larger global field that has since disappeared. Mars has two moons, Phobos and Deimos.