This false-color image of Saturn was constructed by combining three images at three different infrared wavelengths.
The image at the upper left was taken at 1.3 microns, where both Saturn and its rings strongly reflect light. The center image in the top panel was taken at 2.4 microns, where the rings strongly reflect light, but Saturn, because of the methane in its atmosphere, absorbs most of the light. The third image on the right in the panel was taken at a wavelength of 5 microns where, because they are composed of almost pure water ice, the rings absorb almost all the light, and Saturn, because its interior is warm, glows. Assigning each of the three images to blue, green and red, respectively, results in the beautiful, false-color, composite image shown below.
These images were taken on June 21, 2004, with Cassini's visual and infrared mapping spectrometer at a distance of 6.35 million kilometers (3.94 million miles) from Saturn.
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 http://saturn.jpl.nasa.gov/home/index.cfm The visual and infrared mapping spectrometer team homepage is at http://wwwvims.lpl.arizona.edu.