The moon Titan rests on Saturn's razor-thin rings

Saturn's rings are one of the solar system's most brilliant sights, extending for tens of thousands of kilometers and weighing at least thirty quadrillion tons. But in this amazing photograph, you can see just how thin the rings really are.

This image was taken by NASA's Cassini probe, really reveals that, for all the brilliance and size of Saturn's rings, they're strictly a two-dimensional phenomenon. A NASA astronomer explains:

How thin are the rings of Saturn? Brightness measurements from different angles have shown Saturn's rings to be about one kilometer thick, making them many times thinner, in relative proportion, than a razor blade. This thinness sometimes appears in dramatic fashion during an image taken nearly along the ring plane. The robot Cassini spacecraft now orbiting Saturn has now captured another shot that dramatically highlights the ring's thinness. The above image was taken in mid January in infrared and polarized light. Titan looms just over the thin rings, while dark ring shadows on Saturn show the Sun to be above the ring plane. Close inspection of the image will show the smaller moon Enceladus on the far right. Cassini, humanity's first mission to orbit Saturn, currently has operations planned until 2017.

If you can't see little Enceladus, it's the tiny speck right beneath the rings on the far right of the photo, hovering just above Saturn's black bands. Although Enceladus is much smaller than Titan, it's not quite as tiny as this image might suggest - the Enceladus is roughly a tenth the size of the larger moon.

Via NASA.