CICLOPS: Cassini Imaging Central Laboratory for OPerationS

Rhea Eclipses Dione
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Rhea Eclipses Dione
PIA 07770

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  Two crescent moons dance around Saturn as far off Dione slips behind its sibling moon Rhea. From Cassini's perspective, Rhea's bulk (1,528 kilometers, 949 miles wide) completely covered her smaller celestial companion Dione (1,123 kilometers, 698 miles wide) for about three minutes, before the smaller moon re-emerged.

The images used for this movie sequence were taken over approximately 27 minutes as Cassini stared at Rhea. The images were aligned to keep Rhea close to the center of the scene. Additional frames were inserted between the 38 original Cassini images in order to smooth the appearance of Dione's movement - a scheme called interpolation.

For another eclipse movie showing these two moons, see PIA06199.

The clear filter images in this movie were acquired with the Cassini spacecraft narrow-angle camera on December 5, 2005 from a distance of 2.4 million kilometers (1.5 million miles) from Rhea and 2.7 million kilometers (1.7 million miles) from Dione. Image scale is about 14 kilometers (9 miles) per pixel on Rhea and 16 kilometers (10 miles) per pixel on Dione.

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: December 22, 2005 (PIA 07770)
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