Follow this link to skip to the main content

Small Moon Shadow



Category: Rings

Atlas casts a slender shadow on the A ring

Small Moon Shadow
September 7, 2009
Full-Res: PIA11574

Atlas casts a slender shadow on the A ring as the small moon orbits in the Roche Division between Saturn's A ring and thin F ring.

Atlas (30 kilometers, or 19 miles across) is the bright dot right of center.

The novel illumination geometry created around the time of Saturn's 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 Moon Shadow in Motion and Weaving a Shadow.

This view looks toward the unilluminated side of the rings from about 41 degrees above the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 14, 2009. The view was acquired at a distance of approximately 1.6 million kilometers (994,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 86 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 .

Credit: NASA/JPL/Space Science Institute




  • Blend space exploration with reading and writing -- Reading, Writing & Rings!
  • Cassini Scientist for a Day -- Students get involved
  • Cassini Raw Images