Look closely at the outermost set of Saturn's rings in this picture from the Cassini orbiter, and you'll see a series of swoopy streamers pointing inward.

Those faint streamers are created in Saturn's F ring when a 53-mile-wide (86-kilometer-wide) moon called Prometheus dips into it. As Prometheus pulls back, the moon draws out some of the ring's icy material, leaving bright streamers and dark channels in its wake.

Cassini has been studying Prometheus' role in sculpting Saturn's rings for years. This picture was taken by the spacecraft's narrow-angle camera on Feb. 11, from a distance of about 1.3 million miles (2.1 million kilometers). To get a close-up of the action, watch a time-lapse video captured in 2008. And to learn more about the Cassini mission to Saturn, check out NASA's Cassini website as well as the Cassini imaging team's home page.