CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Masked by Methane

Saturn's rings create a brilliant halo around the turbulent giant planet. Here, Cassini looks into Saturn's clouds using a spectral filter sensitive to absorption by methane. Any light detected by the camera using this filter is reflected very high in the atmosphere, before the light is absorbed. Thus, the bright areas in these images represent hazes and clouds high in the atmosphere.

Because the range of wavelengths for this filter is narrow, and because most of this light is absorbed by Saturn, the planet's disk is inherently faint and the exposures required are rather long. The rings do not strongly absorb at these wavelengths, and so reflect more light and are overexposed compared to the atmosphere.

This view looks toward the sunlit side of the rings from about 6 degrees below the ringplane. Janus (179 kilometers, 111 miles across) is seen above the rings at right.

The image was taken with the Cassini spacecraft wide-angle camera on Sept. 25, 2007 using a spectral filter sensitive to wavelengths of infrared light centered at 890 nanometers. The view was obtained at a distance of approximately 2.3 million kilometers (1.4 million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 67 degrees. Image scale is 132 kilometers (82 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 Cassini-Huygens mission for NASA's Science Mission Directorate, Washington, D.C. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission, visit and the Cassini imaging team home page,

Credit: NASA/JPL/Space Science Institute
Released: November 12, 2007 (PIA 09769)
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  Masked by Methane
PIA 09769

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