NASA Mars Reconnaissance Orbiter HiRISE Imagery Release 25 June 2008

Information about the Mars Reconnaissance Orbiter is online at http://www.nasa.gov/mro. The mission is managed by NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology, for the NASA Science Mission Directorate, Washington, D.C. Lockheed Martin Space Systems, of Denver, is the prime contractor and built the spacecraft. HiRISE is operated by t he University of Arizona. Ball Aerospace and Technologies Corp., of Boulder, Colo., built the HiRISE instrument.

	Pedestal Crater Margin A pedestal crater is one with its ejecta standing above the surrounding terrain.

	Polygons, Crater Layers, and Defrosting Dunes Because of the presence of ice, it is difficult to determine all the dune types captured in this image.

	Layers at Margin of Hellas Impact Basin Prominent layers of rock are visible in this image, expressed here as topographic benches and cliffs.

	Indicators of Recent Winds on Mars Small-scale features, such as ripples and wind tails, indicate the most recent wind directions.

	Volcanic and Clay Materials Near Nili Fossae This image is located west of the Nili Fossae trough, one of the proposed landing sites for the Mars Science Laboratory.

	A Crater Superposed on Chaotic Terrain Near the Head of a Dao Vallis Branch This image features a crater at the head of Dao Vallis, one of the Martian outflow channels that drains into Hellas Basin.

	Student Image of the Week: South Polar Spiders In this image, the “spiders” likely caused by the sublimation of carbon dioxide ice.