New images of Saturn's sponge-like moon
Hyperion is Saturn's eighth largest moon at 175km by 100km, and tumbles around its orbit of Saturn once every 21 days. The images in question were taken during a flyby of the moon by Cassini back in September 2005.
Other instruments on the spcaecraft have recently been used to determine what the moon's surface is made of. The ultraviolet imaging spectrograph and visual and infrared mapping spectrometer are detectors capable of mapping the mineral and chemical components of a surface, and have found that most of Hyperion's surface is a mix of frozen water and organic dust, as well as small amounts of frozen carbon dioxide. It is known that when placed under strong ultraviolet light from stars, these chemicals can form more complex molecules, known as hydrocarbons, which are thought to be the essential building blocks of life.
In this map of Hyperion's surface, blue shows up pockets of frozen water, red denotes carbon dioxide ice (or dry ice), magenta indicates regions of water plus carbon dioxide, and yellow is a mix of carbon dioxide and an unidentified material.