PIA03470: Arsia Mons Spiral Cloud
Target Name: Mars
Is a satellite of: Sol (our sun)
Mission: Mars Global Surveyor (MGS)
Spacecraft: Mars Global Surveyor Orbiter
Instrument: Mars Orbiter Camera (MOC)
Product Size: 838 x 838 pixels (width x height)
Produced By: Malin Space Science Systems
Producer ID: MOC2-302
Primary Data Set: MGS EDRs
Full-Res TIFF: PIA03470.tif (1.393 MB)
Full-Res JPEG: PIA03470.jpg (36.53 kB)

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Original Caption Released with Image:

One of the benefits of the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) Extended Mission is the opportunity to observe how the planet's weather changes during a second full martian year. This picture of Arsia Mons was taken June 19, 2001; southern spring equinox occurred the same day. Arsia Mons is a volcano nearly large enough to cover the state of New Mexico. On this particular day (the first day of Spring), the MOC wide angle cameras documented an unusual spiral-shaped cloud within the 110 km (68 mi) diameter caldera--the summit crater--of the giant volcano. Because the cloud is bright both in the red and blue images acquired by the wide angle cameras, it probably consisted mostly of fine dust grains. The cloud's spin may have been induced by winds off the inner slopes of the volcano's caldera walls resulting from the temperature differences between the walls and the caldera floor, or by a vortex as winds blew up and over the caldera. Similar spiral clouds were seen inside the caldera for several days; we don't know if this was a single cloud that persisted throughout that time or one that regenerated each afternoon. Sunlight illuminates this scene from the left/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, 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.

Image Credit:
NASA/JPL/MSSS

Image Addition Date:
2002-02-16