CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Sawtooth Shadows

Jagged looking shadows stretch away from vertical structures of ring material created by the moon Daphnis in this image taken as Saturn approaches its August 2009 equinox.

Daphnis (8 kilometers, 5 miles across) is a bright dot casting a thin shadow just to the left of the center of the image. The moon has an inclined orbit and its gravitational pull perturbs the orbits of the particles of the A ring forming the Keeler Gap's edge and sculpts the edge into waves having both horizontal (radial) and out-of-plane components. See PIA11655 to learn more and to see a movie of this process.

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.

This view looks toward the unilluminated side of the rings from about 43 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 26, 2009. The view was acquired at a distance of approximately 823,000 kilometers (512,000 miles) from Daphnis and at a Sun-Daphnis-spacecraft, or phase, angle of 53 degrees. Image scale is 5 kilometers (3 miles) per pixel.

The Cassini Equinox Mission is a joint United States and European endeavor. 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 was designed, developed and assembled at JPL. 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 Equinox Mission visit, and

Credit: NASA/JPL/Space Science Institute
Released: July 30, 2009 (PIA 11547)
Image/Caption Information
  Sawtooth Shadows
PIA 11547

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Alliance Member Comments
mipsandbips (Jul 30, 2009 at 8:02 PM):
Once more the shadow of the ripple takes center stage!
stowaway (Jul 30, 2009 at 11:06 AM):
Once again - the wild and wily waves of dainty daughter Daphnis effecting ever elongating eclipses.
Red_dragon (Jul 30, 2009 at 8:07 AM):
Gravity's tricks are truly amazing and this image show that very well.