by Zibi Turtle
That Saturn's little moon Enceladus has active plumes venting material from its south pole is incredibly exciting. Perhaps even more intriguing, however, is that the activity is so localized and that Enceladus' surface exhibits such a wide range of geologic terrains, potentially reflecting heterogeneity in its interior.
The youth of the South Polar Terrain is demonstrated not only by the current activity observed there but also the lack of impact craters.
These observations give us important clues about Enceladus and its interior. That the geologic activity varies so significantly across the surface, from currently active areas to others likely eons old, suggests that the heat reaching the surface from the interior also varies from place to place. However, even the oldest areas, appear to have undergone some subtle modification, demonstrating that they, too, are not without some heat from the interior. In order to understand Enceladus, it's essential to consider the moon in its entirety.