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]

Some of the criteria that seem to be needed for us to see such a feature are

*ancient surface

*object needs to approximate a sphere

*object may need to be remote from other objects (our own moon does not seem to have low circular orbits stable enough for there to be enough time for a ring system to form and emplace. Materials in randomly inclined lunar orbits will contact the lunar surface prior to colapse to the Laplacian plane)

*object needs to have a surface sufficiently solid and rigid for the materials to emplace on

*object needs a very low density (prefer none) atmosphere or materials will drop all around the equator.
(we may see such structures someday, but they won't look like the Iapetan ridge formation).

*object needs to be somewhere an appropriate glancing impact can loft materials is likely to occur. Iapetus may have encountered an 'outie' satellite of Saturn or a displaced Saturnian Trojan object