On a ring origin of the equatorial ridge of Iapetus Options

[Guest_AlexBlackwell_*]

Wing Ip just had an interesting Iapetus-related paper published in GRL.

[tasp]

Regarding perturbations of a possible Iapetan ring system by distant Saturn and perhaps Titan, what would be the effect?

The ring system will self-correct any out of plane displacements fairly rapidly. The ultimate result of out of plane deflections would be a slightly increased ring thickness overall, and a bit more pulverization of the already pretty well fragmented ring chunks themselves.

I am not sure we need to worry about the out of plane deflections too much at all.


What about deflections in plane?

Well, the individual ring particles each have their own orbit about Iapetus, increasing their orbital eccentricities a bit will mostly enhance the already existing dynamical ring spreading process which transfers momentum across the ring plane via the individual ring particles bumping into each other. If they bump a little harder, or a little more often, to what effect? Ultimately, we might expect the emplacement rate on the Iapetan surface to be somewhat higher than in an identical system without the in plane perturbations.

I had calculated at one time that a 1 cubic meter per second deposition rate will make quite a heap in ~350 years, and even in the actual perturbed Iapetan system, I doubt we get the ring system down that fast anyhow.

It would be hard to see how the ridge system would be vastly different had it emplaced in 200 years or 2000.


So, I am not to sure that tidal effects from Saturn, Titan, or even the distant sun are going to have much impact on the evolution of a possible Iapetan ring system . . . . .



(hopefully my 'no math' approach (OK, a little math seeps in once in a while) to all this isn't driving the rest of you to distraction too badly)