Sublunar Network of Rivers and Lakes?, If water is confirmed... Options

[Webscientist]

I've always been surprised to hear that the moon is a dead world with no water at all on its surface.
Now, the recent finding of water radically changes our approach of the moon.
If there is water in the soil, that implies that water has the ability to infiltrate into the dusty soil of the moon instead of vanishing into outerspace.
You see what I mean!
The prospect of a network of caves carved by liquid water beneath the surface of the moon can be envisaged.
You may find a similar pressure to that of the Earth at sea level about 30 meters beneath surface level on the Moon.
What are the thermal conditions at this depth? Can water appear in its liquid form?...

[nprev]

Sorry, but I would call that unlikely to the point of impossibility. Even a pond-sized, very localized underground aquifier would produce a global water signature many orders of magnitude greater than that observed due to transpiration through bedrock cracks & the loose regolith and subsequent diffusion through what passes for the lunar atmosphere.

Transient lunar phenomena (TLP) have been documented occasionally over the years, and some (esp. in the Aristarchus region) do seem to be related to gas emissions, the rest probably being meteor impacts. However, the only spectrum (hastily!) obtained for a TLP reportedly did not show H2O or OH.

[Juramike]

Even a pond-sized, very localized underground aquifier would produce a global water signature many orders of magnitude greater than that observed due to transpiration through bedrock cracks & the loose regolith and subsequent diffusion through what passes for the lunar atmosphere.

Hmmm. Not sure I can agree with that statement. If I understand correctly, there are very large underground deposits of ice on Mars that have not been observed spectroscopically through bedrock cracks and loose regolith. That is why the crater impacts were required to expose the ice on Mars.


But getting back to the Moon, it could be a pure diffuse surface absorption onto the rock/dust grains. The H2O molecules deposit onto the outer few microns of the dust and is held there as a "solid". Any diffusion (not using the word percolation) in the soil column would be through sublimation-diffusion-redeposition onto deeper dust grains in the surface. I don't think there would ever be anything remotely resembling liquid flow (not even during or after an impact.)

Could it concentrate in an underground cold trap? Maybe. Then you could get a subsurface ice deposit. But it would likely be diffusing in and filling in the spaces of the dust grains to make a frozen dirt clod.

(Could the frozen dirt clod eventually deform plasticly and flow? That I don't know. That's where the total amount that exists is important. There just might not be enough H2O to do such a localized concentration.)

-Mike