The shadow of the moon Mimas strikes the F ring at a different angle than
the angle at which it is cast on the A ring, illustrating differences in
the vertical heights of the rings in this image taken as Saturn approaches
its August 2009 equinox.
The novel illumination geometry that accompanies equinox lowers the sun's
angle to the ringplane and causes out-of-plane structures to cast long
shadows across 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.
Pan (28 kilometers, or 17 miles across) orbits in the Encke Gap and is
visible on the left of the image. The brightness in the lower left of the
image is lens flare, a radially extending artifact that results from light
being scattered within the camera optics. The shadow of Saturn cuts across
the lower right of the image. Two stars can be seen through the rings.
Other bright spots in this image are also background stars.
This view looks toward the unilluminated side of the rings from about 52
degrees above the ringplane. The image was taken in visible light with the
Cassini spacecraft wide-angle camera on June 15, 2009. The view was
obtained at a distance of approximately 1.8 million kilometers (1.1
million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle
of 90 degrees. Image scale is 103 kilometers (64 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.