The figure used for the Stanford Torus is 4.5 tons per square meter. A NASA calculation has 4.41 tons per square meter
Page on nasa.gov
It's sort of like how long is a piece of string. If you only plan to spend a year or so there you don't need so much. If you are going to spend an entire lifetime there, and especially if there will be young children, you want it equivalent to Earth pretty much.
Anyway water is 1 metric ton per square meter so that's 4.5 meters thickness of water. Ceres density is 2 tons per square meter and lunar regolith varies from 1.35 at the surface to about 2 for the densest material.
So I think compressed lunar regolith could be about 2 tons per square meter.
So that makes it a little over 2 meters thickness of regolith.
Though it's possible that early settlements on the Moon could be in caves, if so you don't need any shielding because you are underground.
And according to one recent study, the caves could be huge, it's possible that the moon has city sized caves. These would be ordinary lava tube type caves - but on the Moon they can be huge because of the low gravity - and still stable.
So - it's possible - not at all confirmed - that somewhere on the Moon there could be caves large enough to fit a modern city inside.
This shows the city of Philadelphia inside one of these posited lunar caves.
If so they would be a natural place to build a base first of all in the solar system I think outside the Earth.
See Study claims lunar caverns could hold city-size colonies
And even if they are just small lava tube caves as on Earth, it's a natural place for a small settlement.
Though - I think we should study them with unmanned rovers first, same everywhere in the solar system. Because once you bring humans there there is no way you can keep it in its original state - even caves on the Earth like the Lascaux cave, and tourists, you get this effect. But on the Moon, place that has never seen an Earth atmosphere or humans or any form of life, then I can't imagine you could have humans visiting it without changing it a lot.
And there may be a lot of interest in knowing what the cave was like before the humans got there. I think we can afford to take our time myself, and to study all the places that are of interest to us first before we decide to go there in person, if we do. And the first place we find also may not be the best place for humans anyway. If you plan a vigorous human spaceflight program, you can probably do these robotic precursor missions for a fraction of the cost of the main program, and also could save very expensive mistakes and learn things that are of value for both science and human spaceflight before you go there.
Page on nasa.gov
It's sort of like how long is a piece of string. If you only plan to spend a year or so there you don't need so much. If you are going to spend an entire lifetime there, and especially if there will be young children, you want it equivalent to Earth pretty much.
Anyway water is 1 metric ton per square meter so that's 4.5 meters thickness of water. Ceres density is 2 tons per square meter and lunar regolith varies from 1.35 at the surface to about 2 for the densest material.
So I think compressed lunar regolith could be about 2 tons per square meter.
So that makes it a little over 2 meters thickness of regolith.
Though it's possible that early settlements on the Moon could be in caves, if so you don't need any shielding because you are underground.
And according to one recent study, the caves could be huge, it's possible that the moon has city sized caves. These would be ordinary lava tube type caves - but on the Moon they can be huge because of the low gravity - and still stable.
So - it's possible - not at all confirmed - that somewhere on the Moon there could be caves large enough to fit a modern city inside.
This shows the city of Philadelphia inside one of these posited lunar caves.
If so they would be a natural place to build a base first of all in the solar system I think outside the Earth.
See Study claims lunar caverns could hold city-size colonies
And even if they are just small lava tube caves as on Earth, it's a natural place for a small settlement.
Though - I think we should study them with unmanned rovers first, same everywhere in the solar system. Because once you bring humans there there is no way you can keep it in its original state - even caves on the Earth like the Lascaux cave, and tourists, you get this effect. But on the Moon, place that has never seen an Earth atmosphere or humans or any form of life, then I can't imagine you could have humans visiting it without changing it a lot.
And there may be a lot of interest in knowing what the cave was like before the humans got there. I think we can afford to take our time myself, and to study all the places that are of interest to us first before we decide to go there in person, if we do. And the first place we find also may not be the best place for humans anyway. If you plan a vigorous human spaceflight program, you can probably do these robotic precursor missions for a fraction of the cost of the main program, and also could save very expensive mistakes and learn things that are of value for both science and human spaceflight before you go there.
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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