THEMIS Vistas

SHARP WINDS. Memnonia Sulci, seen here, is a small part of a giant geologic unit named the Medusae Fossae formation. Believed by scientists to be comparatively young, the formation has been extensively eroded by winds that have carved the soft materials into long ridges called yardangs. The formation's nature is unknown, but scientists think it may be mostly volcanic ash. This view looks northwest from an altitude of about 20 kilometers (12 miles); no vertical exaggeration. (A 4.6 MB version of the image is available.) Image credit: NASA/JPL/Arizona State University, R. Luk.

To explore Memnonia Sulci further, see Where the Wind Has an Edge.