I remember so many widely publicised suppositions about water under the Solis Lacus formation, its presence often linked with the outflow from the Valles Marineris system.

There were very strong instrument indications of water vapor over Solis, and some indications of liquid water beneath the surface.

Yet the GRS seems to register nothing. It's vexing, and I'll be happy to see your take on it.

Meanwhile, the notion of glacial action on the Tharsis volcanoes and the possibility of current icy deposits on and near them is intriguing. Could they be "mud volcanoes?" (That was raised to help explain the enormous length and extent of some of the flows.) Is there any way to tell with current instrumentation?

The collapse of the northwest side of Pavonis, Arsia, and Ascraeus Mons -- or rather the lobate flows -- is still enigmatic to my mind, but check out some of the MOC images. Some areas seem "muddy" to me.

I suspect there will be both visible and GRS seasonal variations.

I've long suspected current subsurface flow from the base of the North Pole toward the equator.

Medusae looks a lot like an eroding polar deposit to me. Water would be expected, eh?

Cheers, BRFelix