CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Dione Divided

Dione Divided
PIA 18358

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  Dione appears to be cut in two by Saturn's razor-thin rings. And while this is just a trick of the geometry, this tells us something really interesting about Dione and the rings.

Since Saturn's rings appear very thin in this image, we know that Cassini was nearly in the same plane as the rings themselves. (Just like looking at a piece of paper: it is thinnest when seen edge-on.) But since Dione (698 miles or 1123 kilometers across)is lined up in the image as well, Dione must also be in that same plane! In fact, Dione orbits in the same plane as the rings, so any image of Dione being sliced in two by the rings would also feature (appropriately) razor-thin rings.

This view looks toward the sunlit side of the rings from about 0.02 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 25, 2015.

The view was acquired at a distance of approximately 1.4 million miles (2.3 million kilometers) from Dione and at a Sun-Dione-spacecraft, or phase angle of 115 degrees. Image scale is 8.6 miles (13.8 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, and

Credit: NASA/JPL-Caltech/Space Science Institute
Released: February 15, 2016 (PIA 18358)
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