We've known for some time that geysers on Saturn's moon Enceladus sprays water vapor that eventually finds its way to Saturn. But this striking image lets us see that water vapor spilling into space.
Michael Benson composited this image from image fragments sent by the Cassini spacecraft, just one of the incredible bits of space porn from his upcoming book Planetfall: New Solar System Visions. The Enceladus geysers can blast 500 pounds of water vapor per second, and some of that water finds its way into Saturn's atmosphere. It's also believed that the vapor helps form one of Saturn's outer rings, the "E" ring, in the form of ice. So far, this relationship of a satellite feeding materials into its planet, is unique to Enceladus and Saturn. We don't know yet of other moons and planets with a similar relationship. (Note: Moralltach notes in the comments that materials from Io's volcanic eruptions form the Io torus, a gas ring around Jupiter. Enceladus is believed to be responsible for the water that exists in Saturn's atmosphere as well as around the planet, which is what makes it so unusual.)
For now, though, we can just focus in on the incredible beauty of Enceladus itself, and the glow of water vapor shooting into space. To see an enormous, detailed version of this image (and for details on how Benson assembled the image), head over to North Country Public Radio.