Dark dunes overriding bright dunes

Dark dunes overriding bright dunes

. In this picture, wind has caused the dark and somewhat crescent-shaped dunes to move toward the lower left, across sets of smaller, bright ridges that also formed by wind action. All of these dunes are located on the floor of an impact crater in western Arabia Terra. This image was taken from the Mars Global Surveyor in February 2000. It is about 2.1 kilometers wide and centered near 10.7 degrees north and 351.0 degrees west. (Courtesy of NASA, JPL and Malin Space Science Systems.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University