From the NASA Photojournal site:

Impact-battered Mimas steps in front of Saturn’s rings, showing off its giant 130-kilometer (80-mile) wide crater Herschel.The illuminated terrain seen here is on the moon’s leading hemisphere. North on Mimas is up and rotated 20 degrees to the left. Mimas is 397 kilometers (247 miles) across.

The image was taken in visible green light with the Cassini narrow-angle camera on Oct. 13, 2005 at a distance of approximately 711,000 kilometers (442,000 miles) from Mimas and at a Sun-Mimas-spacecraft, or phase, angle of 112 degrees. The image scale is 4 kilometers (3 miles) per pixel.