Pushing and Pulling
Pushing and Pulling
July 30, 2010
Rather than being an unchanging disk of peaceful particles, the material that makes up Saturn's rings is constantly pushed and pulled into spectacular shapes.
On the left of the image, the moon Daphnis (8 kilometers,or 5 miles across) affects material as it orbits in the A ring's Keeler Gap. The moon's orbit is inclined relative to the plane of Saturn's rings. Daphnis' gravitational pull perturbs the orbits of the particles forming the Keeler Gap's edge. This sculpts the edge into waves having both horizontal (radial) and out-of-plane components. Material on the inner edge of the gap orbits faster than the moon so that the waves there lead the moon in its orbit. Material on the outer edge moves slower than the moon, so waves there trail the moon. See Wavy Shadows to learn more about this process.
On the right, the material at the edge of the Encke Gap shows waves caused by Pan (28 kilometers, or 17 miles across). See Ring-Moon Connections for a similar view.
This view looks toward the southern, unilluminated side of the rings from about 6 degrees below the ringplane.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 3, 2010. The view was acquired at a distance of approximately 531,000 kilometers (330,000 miles) from Saturn and at a sun-Saturn-spacecraft, or phase, angle of 33 degrees. Image scale is 3 kilometers (2 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