Mars Global Surveyor
Mars Orbiter Camera
Layers and a Dust Devil in Melas Chasma
MGS MOC Release No. MOC2-230, 22 May 2000
50% Size View 180 KBytes
Full Resolution View 680 KBytes
One of the earliest observations made by the Mars Global Surveyor
(MGS) Mars Orbiter Camera (MOC) was that the upper crust of the planet
appears to be layered to considerable depth. This was especially
apparent, early in the mission, in the walls of the the Valles
Marineris chasms. However, layered mesas and mounds within the
Valles Marineris troughs were recognized all the way back in 1972 with
Mariner 9 images. The MOC image presented here shows many tens of
layers of several meters (yards) thickness in the walls of a mesa in
southern Melas Chasma in Valles Marineris. Erosion by mass
wasting--landslides--has exposed these layers and created the dark
fan-shaped deposits seen near the middle of the image. The floor of
Melas Chasma is dark and covered with many parallel ridges and grooves
(lower 1/3 of image). In the lower left corner of the picture, a
bright, circular dust devil can be seen casting a columnar shadow
toward the left. This image, illuminated by sunlight from the
right/lower right, covers an area 3 kilometers (1.9 miles) wide and
8.2 kilometers (5.1 miles) long. The scene is located near
10.1°S, 74.4°W and was acquired on July 11, 1999. North is
toward the lower left.
Image Credit: NASA/JPL/Malin Space Science Systems
Malin Space Science Systems 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.
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