North Polar Layered Deposits
HiRISE Image TRA_000825_2665This image of the north polar layered deposits was taken during the summer season (solar longitude of 113.6 degrees), when carbon dioxide frost had evaporated from the surface. The bright spots seen here are most likely patches of water frost, but the location of the frost patches does not appear to controlled by topography. Layers are visible at the bottom of the image, mostly due to difference in slope between them. The variations in slope are probably caused by differences in the physical properties of the layers. Thinner layers that have previously been observed in these deposits are visible, and may represent annual deposition of water ice and dust that is thought to form the polar layered deposits. These deposits are thought to record global climate variations on Mars, similar to ice ages on Earth. HiRISE images such as this should allow Mars' climate record to be inferred and compared with climate changes on Earth.
Image TRA_000825_2665 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on September 29, 2006. The complete image is centered at 86.4 degrees latitude, 172.1 degrees East longitude. The range to the target site was 316.2 km (197.6 miles). At this distance the image scale ranges from 63.3 cm/pixel (with 2 x 2 binning) to 126.5 cm/pixel (with 4 x 4 binning). The image shown here has been map-projected to 50 cm/pixel. The image was taken at a local Mars time of 12:26 PM and the scene is illuminated from the west with a solar incidence angle of 63 degrees, thus the sun was about 27 degrees above the horizon. At a solar longitude of 113.6 degrees, the season on Mars is Northern Summer.
Images from the High Resolution Imaging Science Experiment and additional information about the Mars Reconnaissance Orbiter are available online at:
http://hirise.lpl.arizona.edu/
or
For information about NASA and agency programs on the Web, visit: http://www.nasa.gov. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems is the prime contractor for the project and built the spacecraft. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona.
