Titanian Encounters...

Caption NASA:"The moon Rhea moves behind Saturn's largest moon, Titan, in this Mutual Event imaged by the Cassini Spacecraft.
Mutual Event sequences, in which one moon passes close to or in front of another, help scientists refine their understanding of the orbits of Saturn's moons. Part of Rhea's Southern Hemisphere is also visible here through the haze of Titan's Atmosphere.
Titan has been brightened by a factor of 1.5 relative to Rhea. This view looks toward the anti-Saturn side of Titan and the Trailing Hemisphere of Rhea.

The image was taken in Visible green Light with the Cassini spacecraft narrow-angle camera on Nov. 27, 2009. The view was obtained at a distance of approx. 1,2 MKM (about 746.000 miles) from Titan and from about 2,3 MKM (approx. 1,4 MMs) from Rhea.
Image scale in the original image was roughly 14 Km (approx. 9 miles) per pixel on Titan and about 27 Km (approx. 17 miles) per pixel on Rhea. The image has been magnified by a factor of two and contrast-enhanced to aid visibility".