Northern ice cap of Mars

This image, combining data from two instruments aboard NASA's Mars Global Surveyor, depicts an orbital view of the north polar region of Mars.

The ice-rich polar cap seen at the center of the image is approximately 1,000 kilometers across. The white cap is riven with dark, spiral-shaped bands, visible as deep troughs that are in shadow.

To the right of center, a large canyon, Chasma Boreale, almost bisects the ice cap. Chasma Boreale is about the length of the United States' famous Grand Canyon and up to 2 kilometers deep.