MRO fotografa i due MER e i Vikings su Marte

The new images are available online at links from
http://www.nasa.gov/mission_pages/MRO/news/mro-20061204.html and
http://hirise.lpl.arizona.edu. They are among the earliest from Mars
Reconnaissance Orbiter’s primary science phase, which began in
November.

“We know these sites well at ground level through the eyes of the
cameras on Spirit and the Viking landers,” said Dr. Alfred McEwen of
the
University of Arizona, Tucson, principal investigator for the High
Resolution Imaging Science Experiment camera on Mars Reconnaissance
Orbiter. “Applying that knowledge as we view the new orbital images
will
help us interpret what we see in orbital images from other parts of
Mars
never seen from ground level.”

The camera’s view of Spirit in the midst of the “Columbia Hills” is
quickly being put to use by scientists and engineers who plan the
rover’s daily activities, just as a comparable image taken two months
ago of Spirit’s twin, Opportunity, has aided that rover’s work. A
second
image of the Opportunity site has now been combined with the first for
a
stereo view.

The view of Viking Lander 1 from the high-resolution camera on Mars
Reconnaissance Orbiter reveals the spacecraft’s back shell about 260
meters (850 feet) away and the heat shield nearly four times that
distant. The lander returned the first view from the surface of Mars
and
kept operating for more than six years after its July 20, 1976,
landing.

“The biggest surprise is that you can still see what appears to be the
parachute after 30 years,” said Dr. Tim Parker of NASA’s Jet Propulsion
Laboratory, Pasadena, Calif., whose calculations helped determine where
to point the orbital camera for seeing the Viking landers.

Viking Lander 2, unlike Spirit and Viking Lander 1, had not been
detected previously in images from NASA’s Mars Global Surveyor. One
feature that had been considered a possibility in an earlier image
turned out to be the Viking Lander 2’s back shell, about 400 meters (a
quarter mile) from the lander easily discerned in the image from the
newer, higher-resolution camera.

Parker is identifying some individual nicknamed rocks in the
Viking-site
images that are prominent in famous photographs taken by the landers,
such as “Ankylosaurus,” a rough rock about a meter (three feet) long
near Viking Lander 2, and the larger “Big Joe” near Viking Lander 1.

NASA made imaging of the Viking Lander 2 site an especially high
priority for Mars Reconnaissance Orbiter to help in evaluation of
candidate landing sites for NASA’s Phoenix Mars Lander mission, being
prepared for launch next summer. Phoenix will land at a far northern
site, and the Viking Lander 2 site, though not as high-latitude as
where
Phoenix will go, is the most comparable site of any seen from the
surface of Mars.

“The Viking Lander 2 site, with its combination of lander-based and
orbiter-based imaging, gives us an important anchor for evaluating the
ground roughness and boulder densities at sites where we have only
orbital imaging,” said Dr. Ray Arvidson of Washington University in St.
Louis, chair of NASA’s Phoenix Landing Site Working Group.

The Mars Reconnaissance Orbiter is managed by JPL 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, and the instrument was built by Ball Aerospace and
Technology Corp., Boulder, Colo. For more information, visit
http://www.nasa.gov/mro .

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