Little Moons

The irregularly-shaped moon Janus (181 kilometers, or 113 miles across) and the small ring moon Atlas (32 kilometers, 20 miles across) had just emerged from the darkness of Saturn's shadow when Cassini caught this view of the two moons.

Saturn's bright A ring is largely overexposed in this view, but several other ring details are nicely visible. The image shows two bright regions within the B ring (at right), ringlets of material within the dark, narrow Encke Gap and kinks in the F ring.

North on Saturn is tilted toward upper left. This view is from Cassini's vantage point beneath the ring plane. It is notable that, as Saturn orbits the Sun, its shadow has been steadily creeping farther out along the ring plane and now extends beyond the F ring.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 26, 2005, at a distance of approximately 3.2 million kilometers (2 million miles) from Janus and at a Sun-Janus-spacecraft, or phase, angle of 81 degrees. The image scale is 19 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.

For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org.