Likelyhood for an Ocean on Callisto

[BMAONE23]

In this image of the Valhalla region on Callisto we notice thae numerous rings surrounding the impact basin. Could these rings be the result of a gradual resolidification of the surface over a briny ocean below? Could the cause of the rings be similar to the ripples on a pond when you cast in a pebble?

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Also there seem to be an extrordinary ammount of cratering with apparent central uplift zones. could these also be caused by the existance of a subsurface ocean?

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