This nighttime movie of the depths of the north pole of Saturn taken by
the visual infrared mapping spectrometer onboard NASA's Cassini Orbiter
reveals a dynamic, active planet lurking underneath the ubiquitous cover
of upper-level hazes. The defining feature of Saturn's north polar regions
-- the six-sided hexagon feature -- is clearly visible in the image.
Here, brightness indicates the amount of 5-micron (seven times the
wavelength visible to the human eye) radiation, or heat, generated in the
depths of the warm interior of Saturn that escapes the planet. Clouds at a
depth equivalent to 3-Earth-atmospheres pressure block the light radiating
from below, revealing themselves in dark silhouette against the background
thermal glow of the planet. These deep clouds lie some 75 kilometers (47
miles) underneath the typical ammonia hazes and clouds seen in visual
imagery and are likely composed of ammonia-hydrosulfide, although some may
be composed of water, as on Earth. A prominent feature seen in this polar
view is a strange hexagon wave feature circumscribing the north pole.
This nighttime movie was acquired over a one-hour period on Nov. 10, 2006,
from an average distance of 1.03 million kilometers (621,000 miles) above
Saturn's clouds.
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 was designed, developed and assembled at JPL. The Visual
and Infrared Mapping Spectrometer team is based at the University of
Arizona, where this image was produced.
For more information about the Cassini-Huygens mission visit
http://saturn.jpl.nasa.gov/home/index.cfm. The visual and infrared mapping
spectrometer team homepage is at http://wwwvims.lpl.arizona.edu.
