Cassini took this photo yesterday, May 9th, as 16-mile-wide shepherd moon Pan passed along its path through the Encke Gap. Its shadow falls upon the A ring, pointing toward Saturn.
(I colored the image to approximate visible light coloration based on other true-color calibrations. The original raw image can be seen here.)
Pan is lemon-shaped, its long axis permanently pointed toward Saturn. It makes a complete orbit around the giant planet in about 14 hours, traveling the 202-mile-wide Encke Gap in the A ring. Three other corded ringlets, two seen clearly above, also inhabit the gap, discovered in 1888 by James Edward Keeler and named after German astronomer Johann Encke.
Stars are visible through the rings, illustrating their transparency.
Image credit: NASA/JPL/Space Science Institute/J. Major