Resumed Mars Orbiter Observations Yield Awesome Views 

Dunes of sand-sized materials trapped on the floor of a Martian crater in Noachis Terra, west of the giant Hellas impact basin, captured this view on December 28, 2009. The dunes here are linear, thought to be due to shifting wind directions. In places, each dune is remarkably similar to adjacent dunes, including a reddish (or dust colored) band on northeast-facing slopes. Large angular boulders litter the floor between dunes. This image covers a swath of ground about 1.2 kilometers (three-fourth of a mile) wide, centered at 42.7 degrees south latitude, 38.0 degrees east longitude. Courtesy of NASA/JPL-Caltech/University of Arizona

The High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter resumed making observations in mid-December 2009, following a three-month hiatus. NASA launched the multipurpose Orbiter on August 12, 2005, to advance our understanding of Mars through detailed observation, to examine potential landing sites for future surface missions and to provide a high-data-rate communications relay for those missions.

Carrying the most powerful telescopic camera ever flown to another planet, Mars Reconnaissance Orbiter is able to show Martian landscape features as small as a kitchen table from the spacecraft’s low orbital altitude. Over the course of its mission, HiRISE will photograph many areas totaling about one percent of Mars’ surface in unprecedented detail, revealing features as small as one meter across.

Dunes of sand-sized materials have been trapped on the floors of many Martian craters. Linear dunes are thought to be due to shifting wind directions. In places, each dune is remarkably similar to adjacent dunes, including a reddish (or dust-colored) band slopes. Large angular boulders can be seen littering the floor between dunes.

The most extensive linear dune fields known in the solar system are on Saturn’s large moon Titan. Titan has a very different environment and composition, so at meter-scale resolution they probably are very different from Martian dunes.

A set of new images from the HiRISE camera, now available on the camera team’s HiRISE site, includes

• New Craters on Mars

• Megabreccia in Toro Crater 

• Shield Volcano with a Summit Caldera

• Colorful Streaks 

• Candidate Landing Site in NE Syrtis Major

The University of Arizona, Tucson, operates the HiRISE camera, which was built by Ball Aerospace & Technologies, Boulder, CO. NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, manages the Mars Reconnaissance Orbiter for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft.

Images are posted at: http://hirise.lpl.arizona.edu/nea.php