Shadow Cap

The shadow of Saturn's rings sits upon the northern hemisphere of Mimas like a dark cap. In this Cassini spacecraft view, which looks toward high northern latitudes on Mimas, the moon is just grazing the shadow of the rings.

The two distinct shadow regions seen here are the penumbra and the much darker umbra. An observer within the penumbral region on Mimas would have their view of the Sun partly blocked by the rings. For a viewer within the umbral region, the rings would completely cover the Sun. However, since the rings are not opaque, the Sun would still be dimly visible.

The image was brightened to reveal faint details within the eclipsed region, illuminated dimly by sunlight filtering through the rings.

Another view, Full of Holes, was acquired a few minutes prior to this image, and shows a nearly identical Mimas (396 kilometers, or 246 miles across) before the rings' shadow obscured the surface.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Aug. 4, 2008. The view was acquired at a distance of approximately 143,000 kilometers (89,000 miles) from Mimas and from about 67 degrees above the moon's equator. The Sun-Mimas-spacecraft, or phase, angle in the image is 106 degrees. Image scale is 856 meters (2,808 feet) 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 . The Cassini imaging team homepage is at http://ciclops.org .

Credit: NASA/JPL/Space Science Institute