Ices and Shadows: Saturn's moon Tethys appears to float between two sets of rings in this view from our 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. Image Credit: NASA/JPL-Caltech/Space Science Institute #nasa #space #saturn #cassini #tethys #astronomy #nasabeyond #science