NASA Cassini Image: Prometheus practices its pull

NASA Cassini Image shows Shepherd moon Prometheus hovering just inside the reflective F ring. 

Credit: NASA /JPL-Caltech /Space Science Institute.

Lit by eerie, reflected light from Saturn's F ring (and a casting a faint shadow through a haze of icy "mist") Saturn's moon Prometheus can be seen in the raw image above, captured by Cassini's narrow-angle camera on Feb. 5 from a distance of 667,596 miles (1,074,392 km).

It's also receiving some light reflected off Saturn, which is off frame at the top (where the outermost edge of the A ring and the Keeler gap can be seen.)

As the potato-shaped Prometheus approaches the ring it yanks fine, icy material in towards itself, temporarily stretching the bright particles into long streamers and gaps and even kicking up bright clumps in the ring. It's a visual demonstration of gravity at work.

At its longest Prometheus is about 92 miles (148 km) across, but only 42 miles (68 km) in width.

It circles Saturn in a wave-shaped, scalloping orbit once every 14.7 hours.