From: Robert J. Bradbury (bradbury@aeiveos.com)
Date: Fri Dec 14 2001 - 13:55:05 MST
Ooo, ooo, a question I can answer...
The odds on favorite source for the moon at this point is something
like a Mars size body crashing into the Earth very early in its history.
That knocked off a huge amount of surface material -- mostly crust and
upper mantle materials, perhaps some of the core. I think there is still
some debate as to whether the moon has a core (if it does its fairly
small). After all the dust settled the moon would have lost most of
any water it collected from comets (no ozone, means high UV flux
causes dissociation of H2O, loss of H, then O due to low gravity;
once it became tidally locked the temps on the sunny side is going
accelerate any gas molecules to high speed). Lack of H2O means no
normal erosion processes. No oceans in which to dissolve various elements.
Rapid cooling of the core means no plate tectonics, no volcanos or deep sea
vents. So the normal "concentrating" processes you get on the Earth can't
happen there. I think there are only two types of major geological
features the highlands and the mares. I'm not positive but I believe
regions get classified as to whether they are silicate rich or titanium
rich. Perhaps some regions where large impact craters have dug large
holes they may have exposed heaver inner materials. The dust comes
from all the impacts sending up debris that slowly floats back down.
Many of the major mineralogical concentrations found on the Earth
may have had biological inputs as well (certain enzymes need metals
so biological organisms effectively concentrate these). That wouldn't
have occurred on the moon either.
Robert
On Fri, 14 Dec 2001 hal@finney.org wrote:
> Is the moon much the same everywhere in terms of the various ores and
> chemicals that are available? It certainly looks the same, everything
> is covered with gray dust. Or does it have veins of ore as the earth
> does, which would have to be prospected and mined like on earth?
>
> Hal
>
This archive was generated by hypermail 2.1.5 : Sat Nov 02 2002 - 08:12:32 MST