Big Obscures Small

The Cassini spacecraft captures a "mutual event" between Titan and Mimas in front of a backdrop of the planet's rings. This image was snapped shortly before Saturn's largest moon passed in front of and occulted the small moon Mimas, as seen from the spacecraft.

Mutual event observations such as this one, in which one moon passes close to or in front of another, help scientists refine their understanding of the orbits of Saturn's moons. See Catching Big Sister to watch a movie of a mutual event.

Lit terrain seen on Titan (5,150 kilometers, or 3,200 miles across) is on the area between the trailing hemisphere and anti-Saturn side of the moon. On Mimas (396 kilometers, or 246 miles across), the lit terrain is on the moon's Saturn-facing side.

This view looks toward the sunlit side of the rings from just above the ringplane. Part of the rings are in the shadow of Saturn.
The view was obtained at a distance of approximately 1.1 million kilometers (684,000 miles) from Titan and 2.5 million kilometers (1.6 million miles) from Mimas. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Nov. 27, 2009. Scale on Titan is 7 kilometers (4 miles) per pixel. Scale on Mimas is 15 kilometers (9 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 http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Credit: NASA/JPL/Space Science Institute