March 1, 2005
This Cassini image captures three of Saturn's ring moons in a single view. From left to right, the moons seen in this view are Pandora (84 kilometers, or 52 miles across), Janus (181 kilometers, or 113 miles across) and Prometheus (102 kilometers, or 63 miles across).
The ring moons are an interesting study in the dynamics of orbiting bodies. Prometheus and Pandora shepherd Saturn's thin F ring, whose particles orbit between the pair. Prometheus has been observed 'stealing' material from the F ring in images from Cassini. The orbit of Janus is within 50 kilometers (31 miles) of the orbit of another moon, slightly smaller Epimetheus. Janus and Epimetheus exchange positions in their orbital path (inner to outer) every four years.
Saturn's bright, icy rings are overexposed in this scene. However, this has allowed us to see material present within the Cassini Division (near the lower right).
This view is from Cassini's vantage point beneath the ring plane. The image was taken in visible light with the Cassini spacecraft narrow angle camera on Jan. 29, 2005, at a distance of approximately 3.4 million kilometers (2.1 million miles) from Saturn. The image scale is 20 kilometers (12 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 team is based at the Space Science Institute, Boulder, Colo.
Credit: NASA/JPL/Space Science Institute