Saturn's Hyperion: A Moon with Odd Craters
What lies at the bottom of Hyperion 's strange craters? To help find out, the robot Cassini spacecraft that once orbited Saturn swooped past the sponge-textured moon and took images of unprecedented detail. A six-image mosaic from the 2005 pass, featured here in scientifically assigned colors, shows a remarkable world strewn with strange craters and an odd, sponge-like surface . At the bottom of most craters lies some type of unknown dark reddish material . This material appears similar to that covering part of another of Saturn's moons, Iapetus , and might sink into the ice moon as it better absorbs warming sunlight . Hyperion is about 250 kilometers across, rotates chaotically , and has a density so low that it likely houses a vast system of caverns inside.