CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Shadow Between Moons

Shadow Between Moons
PIA 11538

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  The shadow of the moon Mimas is cast on Saturn's outer A ring in this image which also shows a couple of moons and a collection of stars.

Atlas (30 kilometers, 19 miles across) can be seen in the top right of the image, between the A ring and thin F ring. Pan (28 kilometers, 17 miles across) can be seen orbiting in the Encke Gap in the lower left of the image. Mimas is not shown. The bright object between the A ring and F ring on the left of the image is a star. Other smaller, bright specks in the image are also background stars.

The novel illumination geometry created as Saturn approaches its August 2009 equinox allows moons orbiting in or near the plane of Saturn's equatorial rings to cast shadows onto the rings. These scenes are possible only during the few months before and after Saturn's equinox which occurs only once in about 15 Earth years. To learn more about this special time and to see movies of moons' shadows moving across the rings, see PIA11651 and PIA11660.

This view looks toward the unilluminated side of the rings from about 59 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 30, 2009. The view was obtained at a distance of approximately 1.6 million kilometers (994,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 76 degrees. Image scale is 9 kilometers (6 miles) per pixel.

The Cassini Equinox 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 Equinox Mission visit, and

Credit: NASA/JPL/Space Science Institute
Released: July 17, 2009 (PIA 11538)
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