The wind can make wild patterns on both Earth and Mars, especially when it
has lots of sand to work with.
This picture, taken in January and released yesterday, shows wind-sculpted
dunes near the northern polar cap of Mars. The dunes are covered in frost during
late winter in the northern hemisphere of the red planet.
The image was made by NASA's Mars Global Surveyor. It shows an area about 1.9
miles (3 kilometers) wide at 77.8°N, 52.8°W. Sunlight illuminates the scene
from the lower left.
