Annotated figure
This image provides higher-resolution views of a site where another
observation (PIA10247) indicates the
presence of chloride salt deposits. The High Resolution Imaging Science
Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took this
image on March 30, 2007. The colors resemble natural appearance, but are
not true color. The chloride mineral deposit looks bright in tone, like
salt pans on Earth. The deposit seems to be emerging as overlying material
erodes away.
Evidence that this site and about 200 other sites in the southern
highlands of Mars bear deposits of chloride salts comes from observations
by the Thermal Emission Imaging System on NASA's Mars Odyssey orbiter. The
salt deposits typically lie within topographic depressions, as exemplified
in this image. They point to places where water was once abundant, then
evaporated, leaving the minerals behind.
Inset boxes show two areas in greater detail, revealing cracks that formed
as the salt deposit dried. Scale bars are 1 kilometer (six-tenths of a
mile) and 100 meters (110 yards).
The site lies at about 221 degrees east longitude and 38.8 degrees south
latitude, within the rugged Terra Sirenum region of Mars. This view, taken
during southern-hemisphere spring on Mars, is part of a full HiRISE image
at posted at http://hirise.lpl.arizona.edu/PSP_003160_1410.
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, Denver, is the prime contractor for the project and built the
spacecraft. The High Resolution Imaging Science Experiment is operated by
the University of Arizona, Tucson, and the instrument was built by Ball
Aerospace & Technologies Corp., Boulder, Colo.