The High Resolution Imaging Science Experiment (HiRISE) on NASA's Mars
Reconnaissance Orbiter acquired this image during its first day of test
imaging from the spacecraft's low-altitude mapping orbit, Sept. 29, 2006.
This image of Mars' 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 be 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. Shown here is the full image, centered
at 86.5 degree latitude, 172.0 degrees east longitude. The image is
oriented such that north is to the top. The range to the target site was
298.9 kilometers (186.8 miles). At this distance the image scale is 59.8
centimeters (23.5 inches) per pixel (with two-by-two binning} so objects
about 1.79 meters (70 inches) across are resolved. In total the original
image was 12.2 kilometers 7.58 mile; 10024 pixels) wide and 6.1 kilometers
(3.79 miles; 5000 pixels) long. The image was taken at a local Mars time
of 3:30 PM and the scene is illuminated from the southwest with a solar
incidence angle of 63.5 degrees, thus the sun was about 26.5 degrees above
the horizon.
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 Corporation and is operated
by the University of Arizona.