NASA Mars Picture of the Day: Small Gullied Crater

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-914, 18 November 2004

NASA/JPL/Malin Space Science Systems

Middle- and polar-latitude martian gullies remain
as much a mystery today as they were when first
announced in June 2000. Some have argued that
they form by running water, others argue they
required carbon dioxide in liquid or gas form,
still others have proposed that these features
form “dry” by simple landsliding processes (although
landslides elsewhere on Mars do not form
features that look like the martian
gullies). They occur almost
exclusively at latitudes higher than 30° in
both hemispheres, although they are more common
in the southern hemisphere.
This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC)
image shows a very small gully example in a
crater that is only about 1 km across–roughly the
size of the famous Meteor Crater in northern
Arizona. The debris transported through the gullies
was deposited on top of light-toned,
windblown ripples on the floor of the crater,
indicating that the ripples are older.
This crater is located
near 37.9°S, 169.3°W.
The 150 meter scale bar is about 490 feet long.
Sunlight illuminates the scene 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.