Here's an awesome picture to start off the week. The data came from Cassini's flyby of Enceladus on January 31, 2011; it was part of Cassini's January 2012 data release. Most of the visible globe is lit by yellowish light reflected first from Saturn; only a thin crescent receives sunlight. At bottom center, Enceladus' south polar plumes erupt into space. They are back-lit by the Sun. As usual for awesome Cassini color photos posted here, this one was processed by Gordan Ugarkovic.
NASA / JPL / SSI / color composite by Gordan Ugarkovic