... hiding in a Ring of Saturn.
NASA's Cassini spacecraft has found within Saturn's G ring an embedded moonlet that appears as a faint, moving pinprick of light. Scientists believe it is a main source of the G ring and its single ring arc.
Cassini imaging scientists analyzing images acquired over the course of about 600 days found the tiny moonlet, half a kilometer (about a third of a mile) across, embedded within a partial ring, or ring arc, previously found by Cassini in Saturn's tenuous G ring.
The finding is being announced today in an International Astronomical Union circular.
You can see the moon as a bright dot in three different locations in the arc of a planetary ring in this photo:
See an uncropped version of this photo here and here, and more information here.
That's no moon. It's a space station.
http://xkcd.com/307/
Inside Saturn's G-string?
It should be called 'Ngwethu' after the character in Ken MacLeod's Cassini Division as well as the concept.