Enceladus- outlying moon of Saturn.
Bright light on the edge is from the sun, 840 million miles away.
The rest of the light is reflected from Saturn.
Photo source- NASA.
Giant ice jets:
Some of the ice does not fall back onto the surface. Enceladus- by that method- makes its own ring around Saturn:
Enceladus gives off about 550 pounds of water vapor every second. We're seeing some of that at the bottom of the image on this Flickr page.
- the actual NASA photo doesn't show the whole circle of the moon. i needed the whole thing to make an iconic image. so this is a composite, made with Photoshop. the original image is not cropped. it probably looks that way because the spacecraft wasn't quite far enough from the moon. it took as much of it as it could get.