Since 2004, NASA's Cassini orbiter has been collecting data on Saturn, its rings and its moons, capturing breathtaking images of them all as it courses through space.
The photo you're looking at is among the latest of Saturn and its satellites to be captured by Cassini, one that reveals through stunning composition the difference in scale, shape, and orbital position of four of the planet's 62 known moons.
Looming in the background of the image is the moon Titan, Saturn's largest; according to Bad Astronomy's Phil Plait, the haze you see just above the surface of Titan in this image is its thick nitrogen atmosphere (see here for a larger image of Titan and its atmospheric haze, also captured by the Cassini spacecraft).
Shining bright in the foreground of the image is Dione, one of the planet's several icy satellites.
On the far right of the image, lying just outside Saturn's F Ring, is the oblong, football-shaped Pandora (click here for a closer view of Pandora that I'm not completely convinced isn't actually a potato).
The fourth moon is named Pan, and while it's a little tough to identify in this image it's definitely visible. Located in what is known as the "Encke gap" in Saturn's A Ring, Pan is one of just two moons known to orbit inside the planet's ring system, and can be spotted in the gap in the rings on the left of the image up top. Shown here is a more top-down view of Pan orbiting within the Encke Gap, which may help you spot it in the edge-on view of Saturn's rings featured above.
As a side note, I can't quite put my finger on it, but something about the composition of this photo immediately called to mind this poster from Duncan Jones' Moon. Is anyone else picking up on that vibe, or does it simply boil down to this being a black and white photo featuring a giant hovering orb?
[CICLOPS via Bad Astronomy]