Saturn's Moons May Be Younger Then They Look

Here's a story to file under "Unlikely but interesting to think about". Research has been published showing that many of the moons of Saturn are not actually 4 billion years old, but only about 100 million years old. The study suggests that the tidal forces governing the Saturnian moon system and gravitational interactions between moons should very quickly force out inner moons into longer orbits. Models were run to predict how far out the inner moons should have moved out, and were compared to where the moons actually are. Of course, they don't match up. According to the model, the inner moons such as Tethys, Dione, and Rhea are much closer than they should be to Saturn if they are in fact 4 billion years old, and actually haven't moved much at all.

To get a more exact date, the researchers looked at Enceladus. Assuming that the amount of tidal flexing and thus the level of geothermal activity was constant, the scientists were able to estimate just how strong the tidal forces around Saturn are. Using this information and computer models, they estimated that Enceladus had moved from its original orbit to its current one in only 100 million years, making the moon very, very young. The researchers guess that something drastic happened 100 million years ago, reshaping the moons that were present into what we see today while also creating Saturn's dramatic ring system. Now, if Enceladus really is that young, that's bad news for finding any life there. 100 million years, while long on a human scale, is really not enough time for life to develop. But I'm just a bit doubtful about this particular theory. It's interesting, yes, but I think there are too many holes for it to be correct.