The Encke gap displays gentle waves in its inner and outer edges that are caused by gravitational tugs from the small moon Pan. These scalloped edges were captured in a dramatic image taken by Cassini during its insertion into Saturn orbit in 2004.
The Encke gap is a 325-kilometer (200-mile) wide division in Saturn's outer A ring. Pan (26 kilometers, or 16 miles across) orbits squarely in the center of this gap.
The original image was stretched in the horizontal direction by a factor of four to exaggerate the amplitude of the waves, then reduced to half size and cropped to focus on the gap.
The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 23, 2006 at a distance of approximately 290,000 kilometers (180,000 miles) from Saturn. Scale in the original image was 1 kilometer (0.6 mile) 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