The searing arc of light seen here is Saturn's icy F ring, seen nearly edge-on. In the background, Rhea (1,528 kilometers, 949 miles across) is lit by reflected light from Saturn and the rings, with only the slightest sliver of light at its bottom being from direct sunlight. The faint material surrounding the F ring likely lies in the planet's equatorial plane, extending radially farther out and in from the main F ring core. A smaller fraction of this material could be vertically extended, and Cassini's investigations should help to clarify this.