Ices and Shadows
Saturn's moon Tethys appears to float between two sets of rings in this view from NASA's Cassini spacecraft, but it's just a trick of geometry. The rings, which are seen nearly edge-on, are the dark bands above Tethys, while their curving shadows paint the planet at the bottom of the image.
Tethys (660 miles or 1,062 kilometers across) has a surface composed mostly of water ice, much like Saturn's rings. Water ice dominates the icy surfaces in the the far reaches of our solar system, but ammonia and methane ices also can be found.
The image was taken in visible light with the Cassini spacecraft wide-angle camera on Nov. 23, 2015. North on Tethys is up. The view was obtained at a distance of approximately 40,000 miles (65,000 kilometers) from Tethys. Image scale is 2.4 miles (4 kilometers) per pixel.
The Cassini mission is a cooperative project of NASA, ESA (the European Space Agency) and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colorado.