Mars Global Surveyor
Mars Orbiter Camera

MOC--The First Year--Top 10

Water: Sustained Flow


Mars Global Surveyor Mars Orbiter Camera Release:          MOC2-73
Mars Global Surveyor Mars Orbiter Camera Image ID:         568793870.8704

490 KByte GIF


It has been known since the discoveries of Mariner 9 in 1972 that water once flowed on Mars and carved a variety of canyons, valleys, and channels. Some of this water appears to have gushed across the landscape in sudden, massive floods. Other valleys appear to be the result of water that flowed underground and sometimes caused the ground to collapse and sediment to be transported away. But one puzzle that has remained for more than 20 years--did any of these valleys experience sustained flow of liquid water at the martian surface over long periods of time?

MOC image 8704 (above) shows a portion of the meandering canyons of the Nanedi Valles system--one of several valleys that cut through the smooth and cratered plains of the Xanthe Terra region of Mars. The valley is about 2.5 km (1.6 mi) wide. The floor of the valley in the upper right corner of the MOC image exhibits a small, 200 m (660 ft) wide channel that is covered by dunes and debris elsewhere on the valley floor. The presence of this channel suggests that the valley might have been carved by water that flowed through this system for an extended period of time. In other words, instead of a massive, catastrophic flood, this valley might have been incised in a manner similar to rivers on Earth. The valley itself would have widened by a variety of processes in addition to the water flowing along the bottom of the channel--slumps and landslides, wind, and perhaps groundwater flow could have all contributed to these processes.

MOC image 8704 was taken on January 8, 1998. The scene covers 9.8 km by 27.9 km (6.1 miles by 17.3 miles). The image is centered on 5.1°N latitude and 48.26°W longitude. (CLICK HERE for a context image). North is approximately up, illumination is from the left. The image dimensions have been corrected from an original aspect ratio of 1.5. The image is available here in two sizes: full resolution (2.1 MByte GIF) (11.8 meters--39 feet--per pixel) and half resolution (490 KByte GIF) (23.6 meters--78 feet--per pixel). This picture was also the subject of an earlier MGS MOC release on February 2, 1998.

Note: This MOC image is made available in order to share with the public the excitement of new discoveries being made via the Mars Global Surveyor spacecraft. The image may be reproduced only if the image is credited to "Malin Space Science Systems/NASA". Release of this image does not constitute a release of scientific data. The image and its caption should not be referenced in the scientific literature. Full data releases to the scientific community are scheduled by the Mars Global Surveyor Project and NASA Planetary Data System. Typically, data will be released after a 6 month calibration and validation period.

Click Here for more information on MGS data release and archiving plans.

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.

To MSSS Home Page