Scallops at the Edges
July 3, 2009
A scalloped look is created in the edges of the Keeler Gap in Saturn's outer A ring as the moon Daphnis orbits in the gap.
Daphnis (8 kilometers, or 5 miles across) is the bright spot in the narrow gap near the center of the image. The small moon's gravity is great enough, and the Keeler gap in which it resides is narrow enough, to perturb the particles in the ring and create the wavelike patterns seen here. See Among the Waves to learn more about this process. As the planet approaches its mid-August 2009 equinox, Cassini has imaged these vertical structures casting long shadows across the rings (see Rippling Shadows).
This view looks toward the sunlit side of the rings from about 58 degrees below the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 9, 2009. The view was acquired at a distance of approximately 847,000 kilometers (526,000 miles) from Daphnis and at a Sun-Daphnis-spacecraft, or phase, angle of 89 degrees. Image scale is 5 kilometers (3 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.
Credit: NASA/JPL/Space Science Institute