NASA Mars Picture of the Day: Athabasca Vallis Circles

Mars Global Surveyor Mars Orbiter Camera

MGS MOC Release No. MOC2-404, 27 June 2003

NASA/JPL/Malin Space Science Systems

Athabasca Vallis is a large channel system cut by catastrophic
floods in the Cerberus region, south of Albor Tholus, on Mars. The
age and history of Athabasca Vallis is the subject of some current
debate in the Mars science community; some consider it to be
geologically young, others suggest the valley is ancient
and has been exhumed after being buried for an unknown, but
considerable, length of time. The valley system contains evidence
suggesting that lava flows–or, perhaps, mud flows–as well as water,
once poured through this area. This Mars Global Surveyor (MGS)
Mars Orbiter Camera (MOC) image presents another puzzle: odd,
somewhat circular features on the floor of the Athabasca Vallis
near 9.7°N, 203.7°W. Their cause is unknown; some of
the landforms nearby (not visible here) suggest
the circular features are exhumed. This picture was taken in
April 2003; it covers an area 1.7 km (1 mi) across and is
illuminated from the 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.