Exploratour - The Surface of Mars
Polar Caps
This is an image showing ice on the Martian south pole. This huge island of ice is called a polar cap. The north pole also has an ice cap.
The winter poles are the coldest regions of Mars. They can be in the dark for as long as 11 months. But the polar caps of Mars grow and shrink with the season, and sometimes completely disappear!
The presence of the polar caps, and their changes with the seasons, provides evidence of water on Mars.