This is the first color image of Mars from the High Resolution Imaging
Science Experiment on NASA's Mars Reconnaissance Orbiter. At the center
portion of the camera's array of light detectors there are extra detectors
to image in green and near-infrared color bandpasses, to be combined with
the black-and-white images (from red-bandpass detectors) to create color
images. This is not natural color as seen by human eyes, but infrared
color -- shifted to longer wavelengths. This image also has been processed
to enhance subtle color variations. The southern half of the scene is
brighter and bluer than the northern half, perhaps due to early-morning
fog in the atmosphere. Large-scale streaks in the northern half are due to
the action of wind on surface materials. The blankets of material ejected
from the many small fresh craters are generally brighter and redder than
the surrounding surface, but a few are darker and less red. Two greenish
spots in the middle right of the scene may have an unusual composition,
and are good future targets for the Compact Reconnaissance Imaging
Spectrometer for Mars, a mineral-identifying instrument on Mars
Reconnaissance Orbiter (http://crism.jhuapl.edu/). In the bottom half of
the image we see a redder color in the rough areas, where wind and
sublimation of water or carbon dioxide ice have partially eroded patches
of smooth-textured deposits.
This image was taken by HiRISE on March 24, 2006. The
image is centered at 33.65 degrees south latitude, 305.07 degrees east
longitude. It is oriented such that north is 7 degrees to the left of up.
The range to the target was 2,493 kilometers (1,549 miles). At this
distance the image scale is 2.49 meters (8.17 feet) per pixel, so objects
as small as 7.5 meters (24.6 feet) are resolved. In total this image is
49.92 kilometers (31.02 miles) or 20,081 pixels wide and 23.66 kilometers
(14.70 miles) or 9,523 pixels long. The image was taken at a local Mars
time of 07:33 and the scene is illuminated from the upper right with a
solar incidence angle of 78 degrees, thus the sun was 12 degrees above the
horizon. At an Ls of 29 degrees (with Ls an indicator of Mars' position in
its orbit around the sun), the season on Mars is southern autumn.
Images from the High Resolution Imaging Science Experiment and additional
information about the Mars Reconnaissance Orbiter are available online at:
http://www.nasa.gov/mro or http://HiRISE.lpl.arizona.edu. For information
about NASA and agency programs on the Web, visit: http://www.nasa.gov.
JPL, 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.
