NASA Mars Picture of the Day: Inverted Channels of Aeolis

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-913, 17 November 2004

NASA/JPL/Malin Space Science Systems

Mars was once a much wetter world than it is today.
Locked within the martian bedrock are ancient
channels and valleys through which liquids—e.g.,
water—once flowed. In the Aeolis region of Mars,
wind erosion has exposed and inverted a plethora of
ancient channels—stream beds—in a fan-shaped
sedimentary rock unit
near 6.3°S, 208.6°W. This
Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC)
image shows an example. The smooth-looking, sinuous
ridges that run left-right across the image
are the inverted channels. The rugged, sharp-looking
ridges that run nearly north-south (up-down) through
the image are yardangs–ridges formed by wind erosion.
The water (or other liquid) responsible for the original
channels flowed from the left (west) to right/upper right
(east/northeast).
This scene covers an area approximately 3 km (1.9 mi)
across, and is illuminated by sunlight 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, California.
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,
California and Denver, Colorado.