Darkness sweeps over Iapetus as the Cassini spacecraft watches the shadow of Saturn's B ring engulf the dichotomous moon. The image at left shows the unshaded moon, while at right, Iapetus sits in the shadow of the densest of Saturn's rings. North on Iapetus (1,468 kilometers, or 912 miles across) is up and rotated eight degrees to the left. The images were taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 13, 2007 at a distance of approximately 2.3 million kilometers (1.4 million miles) from Iapetus. Image scale is 14 kilometers (8 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 <a href="http://saturn.jpl.nasa.gov">http://saturn.jpl.nasa.gov/home/index.cfm</a>. The Cassini imaging team homepage is at <a href="http://ciclops.org">http://ciclops.org</a>.