This sequence of images shows a faint arc of material in Saturn's G ring, a tenuous ring outside the main ring system. These images were each taken about 45 minutes apart. During this time, the arc (slightly brighter than the ring itself) moves around the outer edge of the ring.
The arc is visible on the lower part of the ring in the first image, just beneath the ansa (or outer edge). In the second image the arc is easily seen on the outer edge, and then faintly just above the outer edge in the third image.
What makes this part of the G ring brighter than other parts is not clear. However, the existence of this arc might hold clues about how this ring was formed and where the material which makes up this ring comes from.
These three images were taken in polarized near-infrared light using the Cassini spacecraft narrow-angle camera on May 24, 2005, at a distance of approximately 1.7 million kilometers (1.1 million miles) from Saturn. Resolution in the original images was about 97 kilometers (60 miles) per pixel. The images have been contrast-enhanced to aid visibility.
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