During its March 1999 operations, the Mars Orbiter Camera (MOC) on board the Mars Global Surveyor (MGS) captured this stunning wide-angle camera view of the western portions of Melas and Candor Chasms in the Valles Marineris canyon system. This view covers an area that is about 80 kilometers (50 miles) wide and 220 kilometers (137 miles) long. Melas Chasma is located at the bottom of the image, Candor at the top. Hints of layers in the canyon walls are evident in this image. Color and albedo (brightness) variations on the floors of each chasm indicate the relative distribution of dark sand and brighter sediments and/or rocks. Dark sand on the floor of Melas Chasma was also seen by MOC in March 1999 (see MOC2-104) and bright layered material was observed in Candor Chasma in April 1998 (see MOC2-59).
The colors shown here are not true colors as they would appear to the human eye. The MOC has cameras that obtain images in red and blue portions of the visible spectrum; the green portion is synthesized using the combined average values of the red and blue channels (a relationship understood from Viking Orbiter imaging in the 1970s). Illumination is from the upper left.
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.