Janus & Prometheus

Caption NASA:"The Cassini spacecraft spies two of the small, irregular moons that patrol the outer edges of Saturn's Main Rings.
Prometheus (102 Km, or approx. 63 miles across) hugs the interior of the F-Ring right of center, while Janus (181 Km, or about 113 miles across) hangs in the foreground below center. Hints of craters can be seen on Janus.
This view looks toward the unilluminated side of the Rings from less than 1° above the Ring-Plane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 14, 2007 at a distance of approx. 1,6 MKM (1 MMs) from Saturn.
Image scale is roughly 10 Km (about 6 miles) per pixel".