John-

An excellent explanation of the fun one can have confusing people (and students) with aerial photography and satillite imagery. We had even more fun switching stereo pairs in field classes and asking why rivers were evidently flowing along ridges instead of in valleys.

I am also fascinated by your speculation on the Mercurians, and their underground civilization. I wonder if they are related to the mole people, whom I last encountered as a teenager in some run-down cinema (one critic described that adventure film as "moving along with the speed of the digestive tract with similar results").

The more I study this recent image from Mercury, the more I'm struck with how similar it appears to a Caribbean sandcrab burrow, the radiating trails are obviously created as they haul out and dispose of the debris from their subterranian engineering efforts.

Cheerily,
Charley Noble