The shadow of the moon Epimetheus is cast onto Saturn's rings, striking
the outer-most part of the A ring and only just nipping the F ring.
Epimetheus (113 kilometers, or 70 miles across) is not shown. Bright
specks in the image are 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 77
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 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.