Shadows reveal the topography of Saturn's south polar vortex. At high
resolution, a new, inner ring of isolated, bright clouds is seen. These
clouds are localized regions of convective upwelling, an important clue to
understanding how heat energy is transported in Saturn's atmosphere.
See PIA11104 for a high-resolution Cassini view that looks more
directly down onto the vortex, compared to this oblique perspective.
Sunlight illuminates the scene from upper right, and the higher altitude
rings of clouds surrounding the pole cast shadows toward lower left. North
on Saturn is up.
The image was taken with the Cassini spacecraft narrow-angle camera on
July 15, 2008, with a combination of spectral filters sensitive to
wavelengths of polarized infrared light centered at 746 and 938
nanometers. The grainy quality of the image is due primarily to the low
signal-to-noise ratio of images taken with the 938 nanometer spectral
filter, which is near the upper limit of the wavelength range the camera
can see. "Signal-to-noise" is a term scientists use to refer to the amount
of meaningful or useful information (signal) in their data versus the
amount of background noise. A higher signal-to-noise ratio yields sharper,
clearer views of features in the atmosphere. The view was acquired from 24
degrees below the ringplane, at a distance of approximately 778,000
kilometers (483,000 miles) from Saturn. The sun-Saturn-spacecraft, or
phase, angle is about 30 degrees. Image scale is 4 kilometers (3 miles)
per pixel.
The Cassini-Huygens mission is a cooperative project of NASA, the European
Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory,
a division of the California Institute of Technology in Pasadena, manages
the mission for NASA's Science Mission Directorate, Washington, D.C. The
Cassini orbiter and its two onboard cameras were designed, developed and
assembled at JPL. The imaging operations center is based at the Space
Science Institute in Boulder, Colo.
For more information about the Cassini-Huygens mission visit
http://saturn.jpl.nasa.gov/. The Cassini imaging team
homepage is at http://ciclops.org.
