Space/Science — HabitableZone

Space/Science » in reply to "The best vacuums available on Earth are less than 10 -8 Pa, less than 10e-13 atmospheres!" Not QUITE true...

re: "The best vacuums available on Earth are less than 10 -8 Pa, less than 10e-13 atmospheres!" Not QUITE true...
gbaikie — (archived)

"To reduce the pressure further you can chill the walls of your chamber so the gasses 'freeze' to the walls... I vaguely remember hearing about a chamber made of copper chilled to liquid helium temperatures that (I think) claimed to reache an atomic density comperable to intergalactic space... "

Well, I vaguely recall that there is something like 7 atoms per cubic cm in deep space. If you recalling correctly it seems to me quite impressive to get down to having say less than 10 atoms per cubic cm. Compared to the Moon's 200,000 molecules per cubic centimeter, one might imagine that the moon is not a good vacuum. Review:
"While no one has ever created a true vacuum--an environment entirely free of matter--chambers used in electronics manufacturing can now produce an environment more than 10 trillion times sparser than the atmosphere at sea level."
http://www.airandspacemagazine.com/ASM/Mag/Index/1995/JJ/tmvc.html
Vs
"The measured abundance of the lunar atmosphere is about 200,000 molecules per cubic centimeter at night. This is about 100 trillion (14 orders of magnitude) times less than in Earth's atmosphere."
http://www.lpi.usra.edu/expmoon/Apollo15/A15_Experiments_CCG.html

For practical purposes it seems that billion dollar electronic manufactuers create Ultra-High Vacuum environments which are comparable to what can be found commonly all over the Moon.
It seems to me that it is extremely likely that level of vacuum on the Moon will vary regionally a fair amount. There is obviously the difference between nite and day. How active the Sun is would also have an influence. One also will have weather in form of micrometeorites which will vary- e.g. obviously when the Moon crosses the path of a tail of comet there will dramatic increase. And there will be regions which will have more out gasing from the Moon's interior than in other regions. And possibly different types regolith- different minerals and different average grain size could affect this. One also has the moon's "mini-magnetospheres" which could have some affect. Obviously the most potenial difference in this regard could be the permanently shadow regions in the polar region. The question is will there be a higher vacuum in these regions or will "the atmosphere" be denser- perhaps even stranger could different craters have significant differences in the "atmospheric" density between them. Or could variation within single crater- super cooled gas of say, 400,000 molecules or more per cubic cm pooling at bottom of crater and 100,000 molecules per cubic cm near the top of crater?

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