Mars, May 21, 2007—Looking like islands without an ocean, glacially carved formations come into sharp focus in an image from the Mars Express orbiter, released May 21 by the European Space Agency.
Captured in 2005, the "breathtaking" image depicts the Deuteronilus Mensae region. Dominating the scene is a 68 mile-wide (110 kilometer-wide) craterlike depression filled with a dark material.
As tall as 3,900 feet (1,200 meters), the cliffs in the region are believed to have been formed in icier times. The downward flow of melted water ice and glaciers likely carved the valleys, giving them the serrated edges seen today.