CICLOPS: Cassini Imaging Central Laboratory for OPerationS
A True "Ring Moon"

A True "Ring Moon"
PIA 09843

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  Janus skirts the edges of Saturn's main rings.

Cassini has shown that this small moon and its co-orbital companion, Epimetheus, also share their orbit with a diffuse ring of fine particles. See PIA08322 for more information about the Janus-Epimetheus ring.

This view looks toward the unilluminated side of the rings from about 11 degrees above the ringplane. Above Janus (179 kilometers, 111 miles across), at upper left, are the narrow F ring and the outer part of the A ring.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 19, 2008. The view was acquired at a distance of approximately 1.5 million kilometers (940,000 miles) from Janus and at a Sun-Janus-spacecraft, or phase, angle of 21 degrees. Image scale is 9 kilometers (6 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 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: February 22, 2008 (PIA 09843)
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