The ring moon Prometheus continues its work shaping the delicate F ring as
Dione looks on. It is easy to see how Prometheus has an irregular, oblong
shape, while Dione is quite round.
The rings are partly cut off by Saturn's shadow at right.
Prometheus is 102 kilometers (63 miles) wide; Dione is 1,123 kilometers
(700 miles) wide.
The image was taken in visible light with the Cassini spacecraft
narrow-angle camera on Dec. 20, 2005, at a distance of approximately 2.5
million kilometers (1.6 million miles) from Dione and 2.2 million
kilometers (1.4 million miles) from Prometheus. The image scale is 15
kilometers (9 miles) per pixel on Dione and 13 kilometers (8 miles) per
pixel on Prometheus.
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 mission for NASA's Science Mission Directorate, Washington, D.C. The
Cassini orbiter and its two onboard cameras were designed, developed and
assembled at JPL. The imaging operations center is based at the Space
Science Institute in Boulder, Colo.
For more information about the Cassini-Huygens mission visit
http://saturn.jpl.nasa.gov. The Cassini imaging team homepage is at
http://ciclops.org.