Three of the small worlds that hug the outer edges of Saturn's immense ring system are captured in this Cassini spacecraft portrait.

The two F ring shepherd moons, Prometheus (102 kilometers, or 63 miles across) and Pandora (84 kilometers, or 52 miles across) are seen flanking the ring at bottom. Janus (181 kilometers, or 113 miles across) is visible near the top of the scene.

The image was taken in visible green light with the Cassini spacecraft wide-angle camera on Jan. 18, 2007 at a distance of approximately 1.1 million kilometers (700,000 miles) from Saturn. Image scale on the sky at the distance of Saturn is 61 kilometers (38 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/home/index.cfm. The Cassini imaging team homepage is at http://ciclops.org.