The Cassini spacecraft shows a section of Saturn and its rings which
includes a special treat made possible as the planet approaches its August
2009 equinox: the shadow of a moon cast on the rings.
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.
The moon casting the shadow, Tethys, is not shown in the image. In the
left-most part of the top of the image, Saturn is overexposed where it is
lit by the sun. The rest of Saturn shown here is dimly lit by ringshine
and light scattered through the rings. See PIA09912 for an image of Saturn
under similar lighting.
Four background stars can be seen in the image.
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
acquired 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 89 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.