CICLOPS: Cassini Imaging Central Laboratory for OPerationS

Methane Painting
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Methane Painting
PIA 18336

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  Why does Saturn look like it's been painted with a dark brush in this infrared image, but Dione looks untouched? Perhaps an artist with very specific tastes in palettes?

The answer is methane. This image was taken in a wavelength that is absorbed by methane. Dark areas seen here on Saturn are regions with thicker clouds, where light has to travel through more methane on its way into and back out of the atmosphere. Since Dione (698 miles or 1,123 kilometers across) doesn't have an atmosphere rich in methane the way Saturn does, it does not experience similar absorption -- the sunlight simply bounces off its icy surface.

Shadows of the rings are seen cast onto the planet at lower right.

This view looks toward Saturn from the unilluminated side of the rings, about 0.3 degrees below the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on May 27, 2015 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 728 nanometers.

The view was acquired at a distance of approximately 618,000 miles (994,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 84 degrees. Image scale is 37 miles (59 kilometers) per pixel.

The Cassini Solstice Mission is a joint United States and European endeavor. 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 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 Solstice Mission visit http://ciclops.org, http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov.

Credit: NASA/JPL-Caltech/Space Science Institute
Released: September 7, 2015 (PIA 18336)
Image/Caption Information


Alliance Member Comments
Robert (Sep 12, 2015 at 3:19 PM):
Ah yes, the artistry of science and nature combined!

I find it fascinating that the compound methane can have such a noticeable, detectable affect and in such distinctive bands considering it represents less than two per cent of the composition of Saturn's atmosphere.

More information about the various light absorbtion and scattering characteristics of gases in Saturn's atmophere can be found in the Ciclops page "Four windows on Saturn" at http://www.ciclops.org/view.php?id=65 or by searching for the article title. There are many other pages with explanations and images that can be found by searching for methane or ammonia.

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