The video and text of Sir Clarke's greeting on the Cassini website. Clarke's books were more "hard science" than most of the other sci-fi I read in my youth, and were a good influence on my early and continuing interest in space exploration. Watching the video and listening to his greeting added a nice touch to the Iapetus flyby.

In the video, Clarke quotes from 2001 (the novel) a paragraph on the spaceship Discovery entering orbit around Iapetus (the text doesn't use the Japetus spelling). The orbit height was 50 miles (~80 Km). Carrying that forth to what we know today, either an equatorial orbit following the ridge or a polar one repeatedly approaching the ridge broadside would provide some spectacular views!

Would such an orbit be stable? What about mascons, if any?


Paolo Amoroso

If any Saturnian moon is going to be lumpy, it would be Iapetus. However, it's possible to maintain an orbit around even a very gravitationally lumpy body, if you pay attention on every rev to what your dispersions are. Just like our Moon, it's not possible to maintain such a low orbit for long unattended, but attended (i.e., with constant adjustments) you can orbit such a body indefinitely.

-the other Doug