What I find so awesome about the recent Iapetus encounter is that here we were all hoping to find answers to the great mystery of Iapetus -- why is one side so much darker than the other?<br /><br />And then it goes and shows us that in fact there's an even bigger mystery -- why it's got such a big ridge around its middle.<br /><br />I love space exploration. <img src="/images/icons/wink.gif" /><br /><br />There are also the incredible "ah-ha!" moments, such as the revelation that Dione's light "streaks" weren't streaks at all. Everybody thought they were streaks of light material across Dione's surface, and so everybody was speculating about what could have produced them. Then Cassini takes these spectacular pictures, and lo and behold, they're not streaks at all -- they're cliffs, sparkling because they are so rough, not because they are actually lighter in color. This is a really exciting time. Cassini has given us so much already, and it's been in the Saturn system for less than a year!<br /><br />Getting back to Iapetus, though, I have to confess I lack the background to really judge any of the theories. The ring collapse idea is rather intriguing, however. It would be fun to see a computer simulation of how that would happen, to see if it's really plausible. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em> -- The Tenth Doctor, "Blink"</font></p> </div>