Nanedi Vallis
This picture of a canyon on the Martian surface was obtained a few
minutes after 10 PM PST, January 8, 1998 by the Mars Orbiter Camera
(MOC), during the 87th orbit around Mars of the Mars Global Surveyor
spacecraft. It shows the canyon of Nanedi Vallis, one of the Martian
valley systems cutting through cratered plains in the Xanthe Terra
region of Mars. The picture covers an area 9.8 km by 18.5 km (6.1 mi
by 11.5 mi), and features as small as 12 m (39 ft) can be seen. The
canyon is about 2.5 km (1.6 mi) wide. Rocky outcrops are found along
the upper canyon walls; weathered debris is found on the lower canyon
slopes and along the canyon floor. The origin of this canyon is
enigmatic: some features, such as terraces within the canyon (as seen
near the top of the frame) and the small 200 m (660 ft) wide channel
(also seen near the top of the frame) suggest continual fluid flow and
downcutting. Other features, such as the lack of a contributing pattern
of smaller channels on the surface surrounding the canyon, box-headed
tributaries, and the size and tightness of the apparent meanders
(as seen, for example, in the Viking image 89A32), suggest formation
by collapse. It is likely that both continual flow and collapse have been
responsible for the canyon as it now appears. Further observations,
especially in areas west of the present image, will be used to help
separate the relative effects of these and other potential formation
and modification processes.
Malin Space Science Systems (MSSS) and the California Institute
of Technology built the MOC using spare hardware from the Mars
Observer mission. MSSS operates the camera from its facilities in San
Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations
Project operates the Mars Global Surveyor spacecraft with its industrial
partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA
and Denver, CO.
Photo Credit: NASA/JPL/Malin Space Science Systems
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