The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's
Mars Reconnaissance Orbiter took two images of the larger of Mars' two
moons, Phobos, within 10 minutes of each other on March 23, 2008. This
view combines the two images. Because the two were taken at slightly
different viewing angles, this provides a three-dimensional effect when
seen through red-blue glasses (red on left eye).
The illuminated part of Phobos seen here is about 21 kilometers (13 miles)
across. The most prominent feature is the large crater Stickney at the
bottom of the image. With a diameter of 9 kilometers (5.6 miles), it is
the largest feature on Phobos. A series of troughs and crater chains is
obvious on other parts of the moon. Although many appear radial to
Stickney in this image, recent studies from the European Space Agency's
Mars Express orbiter indicate that they are not related to Stickney.
Instead, they may have formed when material ejected from impacts on Mars
later collided with Phobos. The lineated textures on the walls of Stickney
and other large craters are landslides formed from materials falling into
the crater interiors in the weak Phobos gravity (less than one
one-thousandth of the gravity on Earth).
This stereo view combines images in the HiRISE catalog as PSP_007769_9010
(in red here) and PSP_007769_9015 (in blue here).
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.
