Mars: A Sheer Close-up.

As the Mars Global Surveyor spacecraft maneuvers toward its final mapping orbit , its cameras have been producing some sharp views of Mars. At a resolution of better than 30 feet per pixel, this image of a portion of the immense canyon, Valles Marineris , highlights the sheer mountain cliffs over 3200 feet tall near the canyon walls . The striking and extensive layering clearly apparent in the triangular mountain face was totally unanticipated. This exciting new result challenges common theories about the surface of Mars and argues that a complex early geological history is responsible for the current Martian landscape .