Out of nowhere emerged a Saturn moon to rival Titan in mystery and activity. Here, suddenly, was an ice world not dead but alive and active, spewing out water ice and oxygen from a youthful surface, creating only the second moon atmosphere known in the Saturnian system. Because Enceladus is so small, the atmosphere is localized rather than global, and it must be replenished constantly to compensate for gas and dust loss to the space. In the process, Enceladus may just help build one of the rings of Saturn.
Near the south pole of the moon lies a roughly parallel group of fractures called the “tiger stripes.” The ice here is brand new, perhaps as young as yesterday. The tiger stripes are the warmest region on Enceladus. At 91 and 89 degrees Kelvin (or minus 296 and minus 299 degrees Fahrenheit), this certainly isn’t paradise, but compared to the surrounding temperatures that range from 74 to 81 degrees Kelvin (or minus 326 to minus 313 degrees Fahrenheit), this is downright balmy. To bring out the differences in temperatures, the pictures shown on this page are in false-color.
Just what is occurring beneath the surface of Enceladus here is not known, though the gravitational tug of war between Saturn and Titan on Enceladus may play a role. As usual, where there is present day activity and the right conditions there is speculation about lifeforms. Heat from below, liquid water or soft(er) ice around you, and oxygen above (albeit at atmospheric pressures barely above that of a vacuum) – all the ingredients for those especially hardy alien lifeforms. The search in on.