Masked by Methane

 

Saturn's rings create a brilliant halo around the turbulent giant planet.

Here, the Cassini spacecraft looks into Saturn's clouds using a spectral

filter sensitive to absorption by methane. Light that reaches down to

depths where methane is prevalent gets absorbed. Regions of the planet

devoid of the clouds and hazes that can reflect this light back to the

camera appear relatively dark. 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 they 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 (181 kilometers, or 113 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 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

saturn.jpl.nasa.gov. The Cassini imaging team

homepage is at ciclops.org.

 

credit: NASA/JPL/Space Science Institute

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