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Vast new stores of water reported on the moon

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Re: Vast new stores of water reported on the moon

#141

Post by gadflyinyoureye »

starbase wrote: post #82
once_inc wrote: post #72

Earlier quoted context omitted.

Hard disagree. Finding 'water' trapped in glass beads isn't something useful to us. Converting that to potable or even just liquid water will take far more energy than taking that water out of Earth's gravity well using conventional rockets. The universe is still a harsh, bleak, unforgiving, inhospitable, irradiated wasteland of empty nothingness. Humans need very specific temperatures, air pressures, atmospheric com…

Are you safer and more comfortable in the universe than your ancestors were 1000 years ago? How about 1,000,000 years ago? How about 1,000,000,000? Thought so.

We have a little pocket of the universe. For a good chunk of it, have fun singing in the vacuum.

Re: Vast new stores of water reported on the moon

#142

Post by stametseater »

arethuza wrote: post #123
RealityVoid wrote: post #90

Earlier quoted context omitted.

Being exposed to radiation does not make something radioactive. Radioactive particles settling on the thing is what usually causes things to become radioactive. We actually use radioactivity to sterilize food.

Neutron activation will make things radioactive?

Correct, the lunar soil is itself radioactive because it's subjected to neutron radiation. What's more, the radioactivity of lunar soil increases with depth; the Apollo 17 Lunar Neutron Probe Experiment found that the radioactivity peaks at about 1 meter under the surface. I believe this is because the lunar soil moderates the incoming high energy neutrons (thermal neutrons are more likely to be absorbed.) This effect means that careful planning would be required when shielding a Moon colony. If you just haphazardly bulldoze lunar soil onto your habitat, you could easily make your problem worse.

Re: Vast new stores of water reported on the moon

#143

Post by IntrepidWorm »

greggsy wrote: post #118
areoform wrote: post #50

Every such discovery reaffirms that the moon is a time machine. Next to (or inside) the ice from the Permanently Shadowed Regions, there may be clues to how life got started on Earth. https://link.springer.com/chapter/10.1007/978-94-007-6546-7_... It's estimated that this trapped ice may be from the Earth and the Moon from 3.6B to 4.2B+ years ago. Along with other volatiles, this may give humanity an unprecedented lo…

I’ve always wondered if this ice could have been the remnants of a comet, which after centuries of slowly spiralling closer and closer, landed gently on the moon in a soft cloud of dust.

There's no fluid bodies on the moon to cushion an incoming asteroid or comet - even if there was an initial gentle capture by the moons gravity, the object would either orbit indefinitely, be cast off, or meet a violent end, scattering atomized material across the surface in a wide debris field. This is why theres so much lunar dust coating the entire surface of the moon, and why that surface is so tremendously scarred. The ice is likely the result of countless violent collisions like this, and the ice crystals that manage to land in shaded craters accumulate while those exposed to the sun quickly sublime away.

Re: Vast new stores of water reported on the moon

#144

Post by Chris2048 »

drtgh wrote: post #111
Brendinooo wrote: post #106

Earlier quoted context omitted.

If water is plentiful and accessible, that could be used as shielding, no?

It is not my field, but if plentiful and accessible, we are talking about several thousand tonnes of water around a small habitat that could theoretically be used. Nevertheless, if I understood right, that immense amount of water would have a limited shelf life until acidification corrodes the containment structures, so it would need to be continuously treated and refrigerated, " Ionizing cosmic radiation is mostly g…

I did a few rounds with an AI on this topic, so excuse me if there are inaccuracies, but:

- According to a study conducted NASA, a 1 mm layer of polyethylene reduces solar and cosmic radiation by approximately 50%

- A 1mm, 1m^2 layer of polyethylene weighs approximately 0.92kg

Maybe the polyethylene would decay, but maybe it can also be remanufactured, harvesting the contaminates in the meanwhile?

That said, this all implies that working under a polyethylene sheet of 5mm would reduce exposure to about 33 mSv a year (assume 8hrs a day working on surface, 260 days/yr).

That said, Maybe robots can work on the surface instead?

Re: Vast new stores of water reported on the moon

#145

Post by wongarsu »

Retric wrote: post #137
slashdev wrote: post #134

Earlier quoted context omitted.

I don’t expect there to be much in the way of heavy elements on the moon. It’s mostly made of lighter stuff that got blasted off in the collision with earth when the moon was formed.

The surface has been slowly bombarded long after the moons creation. So surface mining could have a very different elemental mix than subsurface mining. ~48.5 tons of material hits the earth’s atmosphere per day. The moons smaller, but suck impacts where likely more common in the past * 4 billion years and you’re talking a few feet of such material across the entire surface. https://solarsystem.nasa.gov/asteroids-com…

Impact sites of larger asteroids are also great targets for mining operations. For example there's some speculation about the gigantic impact crater on the far side of the moon containing a gigantic metal lump below the surface

https://en.wikipedia.org/wiki/South_Pole%E2%80%93Aitken_basi...

https://www.independent.co.uk/tech/nasa-moon-mass-crater-met...

Re: Vast new stores of water reported on the moon

#147

Post by fastball »

csomar wrote: post #138
slashdev wrote: post #134

Earlier quoted context omitted.

I don’t expect there to be much in the way of heavy elements on the moon. It’s mostly made of lighter stuff that got blasted off in the collision with earth when the moon was formed.

But shipping from the moon to the earth should be much cheaper? I don't have the math (so someone please do?) but based on the size of the Apollo 11, it seems to be trivial to send stuff to earth.

Escaping the moon's gravity well is basically all you need to get stuff back to Earth.

Re: Vast new stores of water reported on the moon

#148

Post by Chathamization »

jiggawatts wrote: post #59
q7xvh97o2pDhNrh wrote: post #35

Earlier quoted context omitted.

You know, they used to say the same thing about big mountains, right? Here's a slightly older take on it from that era: """ People ask me, 'What is the use of climbing Mount Everest?' and my answer must at once be, 'It is of no use.' There is not the slightest prospect of any gain whatsoever. Oh, we may learn a little about the behaviour of the human body at high altitudes, and possibly medical men may turn our obser…

There's adventure you fund yourself, and then there's adventure that taxpayers fund to the tune of several trillion dollars.

Yeah, if a huge chunk of DARPA's budget was spent sending people to climb mountains "Because it's there," people wouldn't be happy. The NASA budget for aeronautics is 1/8th the budget devoted to sending people into space "because it's there." Yet the aeronautics research is much more likely to have an actual positive impact on people's lives.

Re: Vast new stores of water reported on the moon

#149

Post by NickM »

stainablesteel wrote: post #126
credit_guy wrote: post #113

Just to be clear, the "vast stores" of water are only theoretical. There are no implications for Moon colonies. You are not going to try to extract water from glass beads. You would need to go through thousands of tons of regolith before extracting a single liter of water, and that's only if you have 100% efficiency, which you will not have. If we ever decide to have Moon colonies we'll have 3 big problems: we won't…

a recent megaprojects video claimed harvesting water from asteroids was more worth the time and money than to do the same for rare earth metals. apparently bringing tons of rare earth metals back to earth would only lower their price and therefore not make the trip worth the money, but i guess this isn't a problem for the water that those asteroid might hold as that would still be not only valuable but worth the expe…

That seems like a bizarre take. Even with efficient fully reusable rockets, surely desalination will still be much cheaper than mining water from asteroids and bringing it back to Earth?

And sure, maybe bringing huge amounts of rare earth metals back might reduce the price a bit, but to the point where rare earth elements are cheaper per mass unit than water?

Re: Vast new stores of water reported on the moon

#150

Post by johnwalkr »

thaumasiotes wrote: post #68
TaylorAlexander wrote: post #54

Earlier quoted context omitted.

Reminder that the moon does not have a "dark side". This is a misnomer. The back of the moon gets the same amount of sunlight as the front. Unless you mean the side which is not presently illuminated. Water could freeze there but it would boil off again when the sun lights it up again. However there are craters at the poles that never experience sunlight, and water does accumulate in them. You don't need any atmosphe…

> Reminder that the moon does not have a "dark side". This is a misnomer. It isn't. The side of the moon that cannot be seen from Earth is called the dark side of the moon. It's called that for the same reason that the Dark Ages are called dark: because we can't see them. It is true that the dark side of the moon gets just as much sunlight as the light side does.

I work in aerospace (lunar exploration actually), and everyone involved goes out of their way to always use the term far side and explain to laypeople about it. Regardless of its origin, I've commented on it in conversation at least a dozen times and I don't think I've yet had the other person use the phrase and not also think there is a permanently dark side of the moon.

Online there is often also some pedant who explains "well actually there is a dark side but it changes". Because your last sentence is about sunlight I actually interpreted "dark side of the moon" as the unlit/ lunar nighttime side on the first several reads.

Anyway it can be interpreted at least three ways:

- Referring incorrectly to the far side

- Referring correctly to the far side because actually dark means something else (but it will be interpreted incorrectly anyway)

- Referring to the side currently in lunar nighttime

The terms "near side", "far side", "lunar night" and "lunar day" are much better.

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