The month of January is named for the mythical Roman god Janus, who guarded the gate of heaven. Cassini spied the heavily cratered, irregularly shaped moon of Saturn as it glided along in its orbit, about 11,000 kilometers (6,800 miles) beyond the bright core of the narrow F ring. Only vague hints of the moon's surface morphology are visible from this distance. Janus is 181 kilometers (113 miles) across.

The image was taken in visible light with the Cassini spacecraft narrow angle camera on Jan. 22, 2005, at a distance of approximately 2.5 million kilometers (1.6 million miles) from Saturn. The image scale is 15 kilometers (9 miles) per pixel. The image has been contrast-enhanced and magnified by a factor of two 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 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.