lunar contradictions

Or maybe they've hired people who are more imaginative than you are who see ways of making money that you aren't aware of.

The fuss about radiation at the surface of the moon is pretty strange. Anybody who has thought about moon colonies has seen them as buried under the surface.

A couple of feet of moon rock should stop anything worth worrying about. It won't do anything for neutrinos but they go straight through the earth anyway.

I don't see a contradiction here. Both statements are more or less true but viewed through different tinted glasses. The first sees all the business opportunities "First Starbucks on the moon" that sort of thing.

Whilst the second focusses exclusively on the worst possible scenario.

The private enterprise will do it all view seems highly optimistic to me. I'm not convinced there are any worthwhile mineable resources on the moon - its geology never really got that far to create big ore bodies. Living on the moon the most valuable commodities for the foreseeable future will be water and oxygen. Just surviving will be a challenge.

The Ucrete material I mentioned elsewhere recently was considered for manufacturing lunar habitation from the regolith and now with 3D printing technology it could probably be done piecemeal. ISTR The original project envisioned building a mould and spray casting it.

There might be more useful approach of snaffling iron and precious metals from passing iron meteorites for private enterprise but the insurance issues could be serious if they plonk one onto a major city!

The life in space is potentially dangerous is also true but class X flares that come our way are quite rare. I'm not sure that their claims of the lethality are even remotely true. A few people on Earth have suffered insane neutron flux (and died eventually) but not immediately.

I suspect that space travellers will shorten their lives by doing it but by months or years rather than being instantly killed in a radiation storm (unless say Betelgeuse goes supernova and then all bets are off).

No one's life will be shortened by a few months, very likely. This is a statistical measure, where some people die much sooner than their expected life span, and others are not affected at all. In addition, dying from many of the effects of radiation can be particularly gruesome. Not fun at all. Spend some time with someone dying from cancer. I did, and it was very gruesome indeed. The last couple of weeks, I could not even enter the room anymore. My uncle was gone, but the emaciated body was still heaving, trying to breath a bit of air into the lungs.

Not that anybody knew much about what life was like on the other side of the sea.

The satellites of Jupiter are decidedly damp. If you've got false ideas about what is out there, you can see it as a good deal more deadly than it actually is.

We need that space to lock people who willfully spread misinformation about subjects they don't understand, or don't want other people to understand correctly . We might call them education camps, though the real point would be to sanitise the internet. Oubliettes for people whose contributions need to be forgotten.

What is the annual average soil temperature deep under the lunar surface ? My guess is -18 C or the temperature Earth would have if there were no atmosphere.

That is a bit too cold for agriculture, but allow in some extra heat during lunar day and preventing too much to escape during night would increase the average soil temperature sufficiently.

Red/blue LEDs do not consume very much power during the lunar night, so no huge batteries needed for agriculture under the lunar surface.

It's probably higher than that. The moon does have a molten core,and it is going to have the same sorts of level of radioactive isotopes that the earth does. and it's the heat that they generate that keeps the core hot enough for it to be liquid.

puts the temperature at the surface of the - rather small - molten core at between 1,300 and 1,470 degrees Celsius

Or just dig a bit deeper.,

Depends how much food you need to grow.

Of course if you dig in near the poles and put you solar panels on high towers, at the poles they can stay pointed at the sun al the way through the full rotation period, and you don't need batteries except when the earth gets in the way (and it never eclipses the sun for very long).

...

Maybe not; polar locations, and raised solariums, can benefit from zero-darkness conditions.

Eclipses you can cover with modest battery sizes.

According to Apollo project measurement the lunar surface temperature was -20 C.

Which suggest a temperature gradient of 1 C/km.

In some diamond mines in South Africa the gradient is about 10 C/km and in Iceland even higher.

With lunar surface temperature of -20 C and assuming 10 C/km gradient, you have to dig 2 km deep to reach 0 C soil temperature.

With only 1 C/km gradient, you would have to dig 20 km.

Reduce the water, CO2, temperature and light during the night and the growth can be stopped for the night and resumed during the day.

Install solar panels on the poles and use long power cables to deliver power to colonies closer to the equator.

Alternatively use some nuclear power plants close to the colonies.

BTW, the Russian Lunahod rowers were pressurized and used RTGs heat inside to keep the electronics alive during the night :-).

Polar craters are also where you might hope to find decent quantities of water ice (and also CO2 ice for that matter).

The main thing is that living on the moon will not be easy or even worthwhile. Robotics today can do a much better job so there is no need to risk lives in clumsy space suits to explore either the moon or Mars.

Depends on what your concept is. For natural resources, you can probably get a whole lot more by working out how to mine landfills efficiently.

Using nuclear power to extract metals from sea water is another option. There is enough dissolved uranium to last for zillions of years.

For culture and stories, a thousand tedious robots can’t replace one guy in a pressure suit.

Space travel, like most of Big Science, is a cultural and not an economic activity.

Cheers

Phil Hobbs

Iceland is the tip of a magna plume. The moon doesn't have them

But you wouldn't bother. You'd just use some solar power to keep your tunnels warm.

But you might want to dig that deep just for radiation protection

It can be slowed down. The plants have to stay alive.,

Why bother?

Launching the nuclear power plants from earth on rockets isn't going to be all that popular.

Sounds sensible, but mainly conservative. The Russian instrument literature was full of valve/tube circuits long after even India had gone solid-state.

<powering lunar colonies>

Active the reactor after it has been installed on the moon. Before that the reactor is clean and the uranium isotopes have long half life (i.e. very low radiation). A launch failure would be quite harmless.

However they launch RTGs that are very radioactive during launch and decay in a few decades.

A launch failure would be quite severe. Apollo 13 ?

The lunar night is not completely dark on the visible side of the moon.

During New Moon there is the "Full Earth" shining in the sky.

As seen from the Moon, the diameter is 3.7 times compared to Moon diameter as seen From the Earth, thus the reflecting area is nearly 14 times. The Earth's albedo is at least 2 times compared to the Moon. Thus the illumination level would be about 30 times of full moon on Earth.

Since the Moon stays (nearly) on the same place on the lunar sky, you could have passive reflectors concentrating earthlight into a greenhouse.

Since plants would need protection against intense solar radiation during the day, some blinds could be used that could be turned around to concentrate some earthlight on plants during the night.

That's when the Earth is full; the moon also gets farther from the Sun than Earth in half its orbit, so it sees the night side of our planet just as often; the darkness won't be full, but still has that periodic dark/light cycle and the associated battery requirement.

... but not so much, because when the Earth seems darkest, your side of Luna is facing Mister Sun himself.