PUBLIC INFORMATION OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011 http://www.jpl.nasa.gov PHOTO CAPTION MRPS #83494 August 25, 1997 Chryse Planitia on Mars The Mars Orbiter Camera (MOC) took this image on August 20, 1997, when the Mars Global Surveyor (MGS) was 5.67 million kilometers (3.52 million miles) and 22 days from entering orbit. At this distance, the MOC's resolution is about 21.2 km per picture element, and the 6800 km (4200 mile) diameter planet is about 327 pixels across. North is at the top of the image. The MGS spacecraft pointed the camera at the center of the planet (near the dark, morning sunrise line, or terminator) at 23.6¡ N, 82.1¡ W. At this distance from Mars, only bright and dark markings resulting from variations in the amount and thickness of dust and sand are visible. The large dark marking stretching from the right center northward is Acidalia Planitia, a region of rock and sand with less dust on it than the area immediately to the south, Chryse Planitia. Both Viking Lander 1 and Pathfinder landed in the latter, bright area. In this low resolution image, some of the dark features resemble the "canals" seen prominently in maps created by astronomers of the 19th and early 20th century. Mariner 9 and Viking images show that most of these dark lines are associated with sand deposits that are trapped in rough areas. The Mars Global Surveyor mission is operated by the Mars Surveyor Operations Project managed for NASA by the Jet Propulsion Laboratory, Pasadena CA. JPL is a division of the California Institute of Technology (Caltech). The Mars Orbiter Camera is a duplicate of one of the six instruments originally developed for the Mars Observer mission. It was built and is operated under contract to JPL by an industry/university team led by Malin Space Science Systems, San Diego, CA. The Jet Propulsion Laboratory operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. #####