If I am to understand correctly, the ridge is caused by the buildup from the ring itself. And the reason the ridge is so narrow, is because the the rings themselves are so narrow. i.e. the moon is less than 8 miles on its longest axis, so its shortest axis is only a few miles - and the rings themselves are even thinner - so thin that they bisect the moon. ie. Only the ridge is within the ring plane - the rest of the moon is outside the plane of the ring.
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Yeah, I guess that's quite plausible. Saturns; rings are between 10 metres and 1 km thick.
Last edited by DaveC426913; 2017-Mar-11 at 07:04 PM.