Why colonize Mars and not the Moon?

[sophiecentaur]

We cannot find all we want on Moon. It is a dead rock. Extracting anything apart from oxygen and a few common metals will be incredibly hard.

That's a bit of a sweeping statement, isn't it? The Moon is a pretty vast area on which more or less any part could be used to cherry pick materials (no Oceans, nobody's back yard. What exactly do you mean by "dead rock"? Is there any reason to suspect that the abundance of desirable metals (per square meter) would be any lower than on Earth? In low g, mining and processing could actually be quite a bit cheaper than on Earth as long as it's mainly robot led. (But that wouldn't be classed as a 'colony', perhaps.

 

[Rive]

In low g, mining and processing could actually be quite a bit cheaper than on Earth

Well, the rock is ~ the same but any truck used would work like it's dancing on ice.
Also, is there any kind of natural process on the Moon what would produce deposits?
I have some doubts.

 

[nikkkom]

That's a bit of a sweeping statement, isn't it? The Moon is a pretty vast area on which more or less any part could be used to cherry pick materials (no Oceans, nobody's back yard. What exactly do you mean by "dead rock"? Is there any reason to suspect that the abundance of desirable metals (per square meter) would be any lower than on Earth?

Metals no, but carbon, nitrogen, hydrogen and other volatiles are in short supply on the Moon.

Even "water ice in polar craters" could well end up being some regolith with about the same fraction of water by weight as concrete on Earth. Extracting actual water from that is not much fun.

 

[sophiecentaur]

Metals no, but carbon, nitrogen, hydrogen and other volatiles are in short supply on the Moon.

Even "water ice in polar craters" could well end up being some regolith with about the same fraction of water by weight as concrete on Earth. Extracting actual water from that is not much fun.

I take your point. A shortage of reagents for reducing ores could be an embarrassment but I would have thought that PV energy would achieve most of what's needed - only in a different way.

 

[nikkkom]

You need carbon and hydrogen to produce any sort of plastics, oils, paints, solvents. Many of them also require nitrogen and/or sulfur. Fertilizers need nitrogen. Chlorine is widely used in industry, and IIRC it is also depleted.

Metal production on the Moon will not be the most impacted industry. At least metals are there, even though different processes to produce them may be needed (for example, both iron and aluminium production we use on Earth require carbon).

 

[Al_]

I think Moon and Mars has nothing like that. The most they can produce is some research data. Is that enough?

Did you read the thread? I know it's quite long, but there is a lot about raw materials, transportation costs, and manufacturing.
The Moon is a great place to get materials at first, and then so are lots of the zero-g bodies further out.
https://www.physicsforums.com/threads/why-colonize-mars-and-not-the-moon.899537/page-19

For the moon, you have to carry all the return fuel down lo the gravity well. For the Mars, you have the option to produce fuel locally

Again, did you read the thread? You can make fuel on the Moon. It has ice. https://nssdc.gsfc.nasa.gov/planetary/ice/ice_moon.html

Even "water ice in polar craters" could well end up being some regolith with about the same fraction of water by weight as concrete on Earth. Extracting actual water from that is not much fun.

No. "nearly pure ice crystals " - see the NASA link above.

A shortage of reagents for reducing ores

Then don't reduce ores. Or only small amounts. A huge amount of stuff can be made from raw, non-oxidised metals found on the Moon, from iron meteorites. Lots of stuff can be made from basalt e.g. basalt fibre. Bulk things can use raw iron or cast stone blocks. The fiddly little things with exotic materials can be shipped from Earth at low cost.
Sure, maybe processes will adapt, materials will be substituted, but not as much as you think. the Moon is BIG. We will find stuff.

some zero-g place where fuel and raw material are available at low delta-V.
Maybe Ceres or such?

It's hard to send people there. And robots aren't smart enough to mine on their own. And remote control (telepresence) is just not feasible due to the signal transmission time delay. But it is feasible on the Moon, so that's where we should start.

 

[nikkkom]

No. "nearly pure ice crystals " - see the NASA link above.

"Analysis of the results indicates concentrations of roughly 6% water in the impact area, including nearly pure ice crystals in some spots."

In my book, as water content, that's concrete with frost on it.

 

[Al_]

"Analysis of the results indicates concentrations of roughly 6% water in the impact area, including nearly pure ice crystals in some spots."

In my book, as water content, that's concrete with frost on it.

Plenty there.

"Subsequent data from Lunar Prospector taken over a longer period has indicated the possible presence of discrete, confined, near-pure water ice deposits buried beneath as much as 18 inches (40 centimeters) of dry regolith, with the water signature being stronger at the Moon's north pole than at the south (4). The ice was thought to be spread over 10,000 to 50,000 square km (3,600 to 18,000 square miles) of area near the north pole and 5,000 to 20,000 square km (1,800 to 7,200 square miles) around the south pole, but the latest results show the water may be more concentrated in localized areas (roughly 1850 square km, or 650 square miles, at each pole) rather than being spread out over these large regions. The estimated total mass of ice is 6 trillion kg (6.6 billion tons)."

 

[mfb]

Is there any reason to suspect that the abundance of desirable metals (per square meter) would be any lower than on Earth?

The average can be similar, but Moon is lacking the geochemical processes to concentrate them.
As an example, uranium makes up 3 parts per million of the Earth's crust. Uranium mines are built in places with 1000 to over 20,000 ppm uranium - a thousandfold concentration relative to the average.
On the Moon, the average concentration is lower at 0.3 ppm, but that is not the point: the highest known concentrations are just 2 ppm, an enrichment of less than a factor 10. Source.

How exactly do we transport things around on the Moon, by the way? Rovers will be generally slow (and limited to the day) if they have to run with solar power, they don't have a practical range with chemical storages or batteries, and the idea of nuclear powered rovers is questionable. Wheels will have a hard time with the regolith. It is easy to point out that "some place on the whole Moon has this", and "some other place has that", but that means we have to transport things over hundreds to thousands of kilometers. Just for basic things like water...

 

[Rive]

Did you read the thread?

Yes and no. No, I did not read all the 500+ posts, just the ~ the last 70-80. And yes, this topic is roughly the same as such topics usually are.

The value of the presence of ice is traditionally overestimated. What it actually means is, that if there is something valuable enough on the Moon that it's price can cover two industrial centers and the local ligistics then it's doable.
But diamond won't be enough, not even close.

 

[sophiecentaur]

The average can be similar, but Moon is lacking the geochemical processes to concentrate them.

That's an interesting point. Would the same apply to meteorites that have landed all over the surface. (That was actually what I was thinking of as much as anything.) Is the typical composition of meteorites as homogeneous as the original lunar surface?
If the availability on the Moon is as low as you suggest then there may not be a point in trying to exploit it. I imagine that some serious prospecting would be needed to prove this one way or another.

 

[glappkaeft]

That's an interesting point. Would the same apply to meteorites that have landed all over the surface.

Generally yes although the meteorite/asteroid population is very diverse. The asteroids that meteorits come from have even less geological processes that can concentrate elements but they are also less differentiated than the moon, often much less so. This can be both good or bad if differentiation makes an element concentrate in the core or the crust. Even so the concentration in the crust of a differentiated asteroid are much lower than good locations on earth.

Asteroids that are large enough to be differentiated are also small enough to be shattered. Iron meteorites are thought to remnants of the core of such shattered asteroids. They are extremely rich in iron, nickel, cobalt (together up to 95%) and (to a much lesser extent) other elements who like to snuggle up to iron. They are however pretty rare.

 

[backspace]

Here is something to think about:
We don't have to go to the classic and historical ways we colonized.
The closest to a "mars type colonization" we have is the Amundsen-Scott base at the south pole.
200 people in the summer and only 50 in the winter.
-constant resupply - aircraft extraction for major medical problems -

https://en.wikipedia.org/wiki/Amundsen–Scott_South_Pole_Station

Couldn't find anything on Amundsen-Scott sanitary engineering but I found this article:
Ya got to have a janitor 'cause 50 - 200 people got to go - but we tend not to think about that.

https://en.wikipedia.org/wiki/Space_toilet

Funding space/mars/moon colonies : Come on! You're not going to get every country to contribute 5% of their GDP.
Consider this Oxfam Report.

https://www.oxfam.org/en/pressroom/pressreleases/2017-01-16/just-8-men-own-same-wealth-half-world

 

[sophiecentaur]

Here is something to think about:
We don't have to go to the classic and historical ways we colonized.
The closest to a "mars type colonization" we have is the Amundsen-Scott base at the south pole.
200 people in the summer and only 50 in the winter.
-constant resupply - aircraft extraction for major medical problems -

https://en.wikipedia.org/wiki/Amundsen–Scott_South_Pole_Station

If they had started off with the "Earth Closet" in a big way, and avoided the "Water Closet", many 'city' drainage problems could have been avoided and our rivers would have remained sweet for a couple of hundred years. We now associate that whoosh of water with the 'natural and satisfying way' to deal with our body waste and that has to be seriously un-learned. All that stuff that goes through us is full of things that we can use and any colony, anywhere, will need efficient waste management. In fact, very little is actual Waste. The way stuff is dealt with in space is really not comparable with how the colonists will need to do things. The only similarity would be the need for an extractor fan.

Come on! You're not going to get every country to contribute 5% of their GDP.

I couldn't agree more.

 

[mfb]

You're not going to get every country to contribute 5% of their GDP.

Why 5%?
GPD is $120 trillion (purchasing power parity adjusted). Let's say SpaceX underestimates the ITS cost by a factor 10 for some reason, and the global expenditures for a Mars colony are 0.01% of the current GDP or 12 billions per year. Then we can still afford to fly thousands of people to Mars per year (in groups every 26 months), more than enough to start some sort of settlement. What is 0.01% of your income? Would you even notice that difference? It gets even less if trips are funded privately.

 

[sophiecentaur]

Why 5%?
GPD is $120 trillion (purchasing power parity adjusted). Let's say SpaceX underestimates the ITS cost by a factor 10 for some reason, and the global expenditures for a Mars colony are 0.01% of the current GDP or 12 billions per year. Then we can still afford to fly thousands of people to Mars per year (in groups every 26 months), more than enough to start some sort of settlement. What is 0.01% of your income? Would you even notice that difference? It gets even less if trips are funded privately.

I certainly would not be interesting in funding this out of my taxes and I reckon most other people would feel the same about giving a selected few an exotic holiday (which is how it would be viewed). It's hard enough to justify major rail and road projects out of taxes, when everyone could benefit in a relatively short time. Just because you feel enthusiastic about the project, you can't assume that the rest of us are as keen.

 

[mfb]

I'm not personally interested in thousands of things tax money is used for. That doesn't mean those things shouldn't be funded. Many of them have positive long-term effects for many to everyone (typical for research), some just have positive effects for some people (typical for local projects). I don't say governments should fund holidays for people. Governments should fund fundamental research, and sometimes subsidize developments that need some help to get started but get commercial successes later: It has a great positive long-term effect, but the timescale can be too long for companies to work on that.

 

[sophiecentaur]

Governments should fund fundamental research,

Absolutely and the choice of which research methods would be best is coloured by 'glamour' and adventure. We could get enormous returns from small manned expeditions but the returns from your "thousands" of visitors would be limited. A fraction of that money, spent on robot expeditions could produce much the same results. Things could be different if the results of robot expeditions were to show that human expeditions could actually pay for themselves.
The recent burst of publicity about AI developments could be the harbinger of a very different approach to the possibilities of space exploration.

 

[mfb]

Things could be different if the results of robot expeditions were to show that human expeditions could actually pay for themselves.

That is the idea of a colony. The first expeditions will be science-focused and won't pay for themselves - they will need government funding. But later they could become a profitable business.

 

[sophiecentaur]

That is the idea of a colony.

But that assumes a colony is the 'best way' to get hold of whatever we would be needing from Mars. Also, "the idea" is really not well defined and there are as many ideas as contributors to this thread.
We only 'colonise' the appropriate parts of Earth for our purposes, as a matter of fact. There have been no colonies on the sea bed, for instance (apart from Cousteau's efforts and a very few other projects), yet we make a lot of use of what's down there. It's all a matter of cost benefit and there is nothing on Earth with a comparable cost.
And the other thing - what happens when some disaster hits Earth. That's an entirely different matter and is hardly something that would be planned. In the very distance future, if there happens to be a large established colony on Mars, there would be the possibility of a very few of Earth's population that could be taken in. But, as we have seen recently, refugees are not too well received by many established communities. It could have the makings of a full scale war.

 

[Ken Fabos]

Coming to this discussion a bit late - my 2c worth is that whilst explorations funded by wealthy advanced economies don't have to be financially viable, for colonies it is essential. They survive either self sufficiently or by trade. Or they fail.

Historically the earliest self sufficient colonisation was done by small groups heading out on foot (mostly), carrying all the tools they needed and with all the necessary knowledge within a few minds - in a world that by any standards was extremely hospitable and rich in readily exploitable resources. Trade based colonies that came later relied on well established, economically proven transport and trade infrastructure and specific colonial efforts often made do with what was destined for scrap - ships near or past their regular economic life rather than having to be built from scratch to higher than usual standards. Many such colonies exploited already existing populations for their knowledge of local resources and often exploited their labour as well. They were often invasions as much as colonisations.

Neither self sufficiency nor economically viable trade seems a reasonable prospect for any Mars or Moon colony with technologies currently available. A "lifeboat" scenario requires high degrees of self sufficiency at a minimum yet any reasonable proposal for such colonies means they will be dependent upon the advanced technologies that only large and wealthy economies can provide. As a motivation it seems insufficient to the extraordinary difficulties of making such a lifeboat scenario work, especially without a provable, near term extreme threat to humanity - beyond the provable threats that already face us.

Trade? There may be some financial benefits from the entertainment value - off hand that is the only real prospect of financial return I can see and one that could prove fickle and find itself in competition with much cheaper to produce and probably more entertaining - and more human friendly - CGI version of humans in space. Presumably mineral resources would be essential - but is there anything on Mars that is not obtainable much more cheaply here on Earth? And wouldn't the technological advancements that would make exploiting Mars resources easier also very likely make exploiting (recycling) resources nearer to hand easier? As outposts of a healthy and wealthy Earth based economy that can afford to build a whole technologically advanced transport infrastructure with no reasonable prospects of sufficient financial returns there could be a Mars colony yet even if an enormous enough pre-investment in technologies that are currently hypothetical could achieve a temporarily successful Mars or Moon colony, without the prospects for financial returns to investors here on Earth the funding will be very difficult and it's long term survival - the lifeline to the technologies it needs - will have to be in doubt.

I do wonder if this urge to seek these new horizons should more correctly be seen as a primitive one, better suited to clever hominids in a big, unexplored world where resource rich opportunities, even, especially, for those on the fringes, could still be found that way; dressing it up with the rationale that it's about the future survival of homo Sapiens doesn't make this urge more rational or reasonable. For such a colony to function as a human "lifeboat" it would need to have a history of enduring success for other, economically sound reasons first.

 

[sophiecentaur]

specific colonial efforts often made do with what was destined for scrap - ships near or past their regular economic life rather than having to be built from scratch to higher than usual standards.

That's a very good point - along with all the others that you make in that well written post. There are so many parallels that people try to draw between Space and Earthbound expeditions and the differences are much greater than is generally acknowledged.

but is there anything on Mars that is not obtainable much more cheaply here on Earth?

Good question.

 

[Rive]

... is there anything on Mars that is not obtainable much more cheaply here on Earth?

I think there is just one such thing: experience.
But that won't feed a 'colony' for long.

The same for any places at the bottom of a gravity well. In our solar system those places are just some 'hostile Earth'. We have some of those here for cheap already, and their colonization is just ... poor.
I don't know if zero-g would ever produce anything what can be sold for high price either, but I think for that, at least there is a chance.

 

[mfb]

But that assumes a colony is the 'best way' to get hold of whatever we would be needing from Mars.

Does the US exist to get hold of whatever Europe needs from it? Does Europe exist to get hold of whatever Africa needs from it?

It will take orders of magnitude more effort than with continents on Earth, but we are not in 1500 any more, and in the long run Mars is a place where humans can live. It has all the elements we need, it has sunlight, it even has a 24 hour day. It had an atmosphere and surface water in the past, and it can get them again on a longer timescale.

On Earth we exploited all the easily available deposits of everything, on Mars they are still there. Building a mining infrastructure on Mars is more challenging, of course, but in the long run: There are things on Mars that are easier to find than on Earth.

I don't know if zero-g would ever produce anything what can be sold for high price either, but I think for that, at least there is a chance.

See above: Some crystals maybe. Tourism is also an option. Not at the current spaceflight costs, but at those costs colonization or even large-scale spaceflight won't happen anyway.

 

[sophiecentaur]

Does the US exist to get hold of whatever Europe needs from it? Does Europe exist to get hold of whatever Africa needs from it?

I don't see a parallel there, at all. The relationship between established nations is hardly relevant to this but there are plenty of (lucky) economies that are based almost entirely on exports. What would be relevant to consider would be the many colonies that were established for precisely the reason that a product was available that was needed in the colonising nation. (Sugar from the West Indies, cotton from the south of the North American continent, tea from China) The indigenous population was only regarded as part of the resource that was being used; 'we' sent our own nationals to form the colonies.

Mars is a place where humans can live.

You are assuming that is the 'aim' of humans - i.e that we must expand and multiply. It is a massive assumption which, afaics, is based on 'faith' and tradition rather than rationality. It could be argued that the 'aim' should be to improve the lives of everyone on the planet and to ensure that they all 'get on' better and live without conflict. There is no shortage of resources on Earth - particularly if the population were kept to a reasonable level. What's a reasonable level - you could say that it's the level it would reach when everyone is comfortably off. The more comfortable people are, in general, the smaller families they aim at. I often wonder why a shrinking population strikes terror into people's hearts. I think that is just a Malthusian type of response (unjustified extrapolation) with no good basis.

 

[Al_]

but Moon is lacking the geochemical processes to concentrate them

- and it also lacks processes that dilute and disperse them!
How many elements either react with oxygen or dissolve in water? Aluminum, lithium, sodium, and the salts, carbonates, sulphurs, etc, etc,
When these land in a meteorite, on Earth they just go away.
But on the Moon, just wander over, maybe flick away some dirt, and pick it up.

And the Moon DOES have geochemical processes. Just different ones.
It certainly had long periods of volcanism in the past.

 

[sophiecentaur]

- and it also lacks processes that dilute and disperse them!
How many elements either react with oxygen or dissolve in water? Aluminum, lithium, sodium, and the salts, carbonates, sulphurs, etc, etc,
When these land in a meteorite, on Earth they just go away.
But on the Moon, just wander over, maybe flick away some dirt, and pick it up.

And the Moon DOES have geochemical processes. Just different ones.
It certainly had long periods of volcanism in the past.

I think we need some cited input here. I was certainly expecting an amount of concentrated materials from the meteorites that have 'recently' arrived. I guess finding them in the right places in craters could be a skill that would need to be developed. Would it necessarily be at the centre of the circle?

 

[Al_]

I think we need some cited input here. I was certainly expecting an amount of concentrated materials from the meteorites that have 'recently' arrived. I guess finding them in the right places in craters could be a skill that would need to be developed. Would it necessarily be at the centre of the circle?

Here is a good overview:
http://www.moonsociety.org/certificate/lunargeology.html#tectonic

 

[Rive]

Aluminum, lithium, sodium, and the salts, carbonates, sulphurs, etc, etc,

The only value of these materials is/if they are available for local use.
As a trade material to balance the finance of a colony they are completely worthless.

 

[mfb]

The relationship between established nations is hardly relevant to this but there are plenty of (lucky) economies that are based almost entirely on exports.

Basing the economy on exports is a possible model, but not the only possible model.

You are assuming that is the 'aim' of humans - i.e that we must expand and multiply.

I don't assume that, but passing on the genes is indeed a strong motivation thanks to biology. A species where the individuals don't want to expand and multiply dies out.

The population on Earth should stabilize at some point in this century - this is independent of whatever might happen outside Earth as (with foreseeable technology) no significant fraction of the population will go elsewhere.

Research done for a Mars outpost or colony and research done on Mars will also help on Earth.

- and it also lacks processes that dilute and disperse them!

How is this relevant without any process that would lead to anything that could get dispersed?
I showed this with the example of uranium. I don't want to repeat this for every element, so why don't we go the opposite way? You find some element that is rare on Earth that can be easily mined on Moon in relevant amounts? With a reference to a space agency or other academic research, not to a company that wants to get funding for mining.

 

[Al_]

The only value of these materials is/if they are available for local use.
As a trade material to balance the finance of a colony they are completely worthless.

Indeed that is true.

We are suffering here from a lack of evidence. There are many reasons to think the Moon is rich in resources of all kinds, and yet, the only time people went there they sampled very limited spots, not near the poles, right on (or just below) the surface, and did not have the benefit of modern remote spectral analysis tools.
More recently, many resources have been spotted from orbit, but this is not firm enough proof for some people.

 

[Rive]

We are suffering here from a lack of evidence.

I think what we suffer here is the lack of economics.

There is a fundamental difference in the workings of a scientific (or, given the chance: touristic ) base and a colony. Even if NASA finds some magic tunnels on Moon filled with various raw materials, air and preserved vegetables: ready for immediate population - as a colony it would be still just a dead end.

 

[Al_]

as a colony it would be still just a dead end.

Why?

 

[Al_]

process that would lead to anything that could get dispersed?
I showed this with the example of uranium. I don't want to repeat this for every element

I have already posted about asteroids. (including the huge one made from half platinum)
These asteroids were produced when minor planets collided and their differentiated cores fragmented into separate orbits.
Statistically, some of these are very likely to have landed on the Moon.
This is the process that results in concentrations.

 

[Rive]

Why?

By your standards, what makes a colony? What is a colony?

 

[mfb]

I have already posted about asteroids. (including the huge one made from half platinum)
These asteroids were produced when minor planets collided and their differentiated cores fragmented into separate orbits.
Statistically, some of these are very likely to have landed on the Moon.
This is the process that results in concentrations.

A few rocks scattered around the surface with unknown density is not a good resource. How much is there per square kilometer?
This is all about numbers. Even pure platinum just lying around is not a good source if there is just one gram-sized asteroid per square kilometer.

 

[Al_]

if there is something valuable enough on the Moon that it's price can cover two industrial centers and the local ligistics then it's doable.

The "industrial centers" can be small. Remotely controlled from Earth, with telepresence robots. Solar powered. Two robots, maybe a cover of regolith (maybe not) some sintered bricks made of regolith, solar panels on the ground, a comms dish.
Once you make some money, increase the amount of kit.
Build towards an economy, and a colony.

 

[Rive]

Once you make some money, increase the amount of kit..

The only value of these materials is/if they are available for local use.

Those (common) resources there can save money, but cannot make it. It's a very important difference regarding any kind of colonization.

 

[Al_]

A few rocks scattered around the surface with unknown density is not a good resource. How much is there per square kilometer?
This is all about numbers. Even pure platinum just lying around is not a good source if there is just one gram-sized asteroid per square kilometer.

Reckon it would be just fine!
Map the gram-sized flakes from low orbit, send a solar-powered robot to trundle along, it goes about 1km per 1g of platinum.
Sounds like a plan!

 

[mfb]

Map the gram-sized flakes from low orbit

Where is the satellite that can do this?
Where is the rover that can scoop them up for significantly less than $30 per gram? If that rover costs 10 million, you have to clear 300,000 km² just to cover rover investment costs - that is the size of Germany. If the rover, operation and the remaining infrastructure costs a billion, you cannot make profit even if you exploit the whole surface area of Moon.

All those numbers are pointless because they are based on numbers I made up. I still don't see any reliable numbers for useful resources on the Moon.

 

[Al_]

Those (common) resources there can save money, but cannot make it. It's a very important difference regarding any kind of colonization.

You're mixing up two replies.
The money is made from the expensive rare metals, exported. (Gold, Platinum, rare Earth's)
The other ones are useful in situ. (Aluminum, lithium, sodium, and the salts, carbonates, sulphurs, etc, etc,)

By your standards, what makes a colony? What is a colony?

We've covered this earlier in the thread. My definition is that people raise families, and there are enough people to create a viable self-sustaining community. It would need to have enough advantages and comfort that most people chose not to go back to Earth.

I came across this theory: "late veneer hypothesis"
http://www.nature.com/nature/journal/v520/n7548/full/nature14360.html
Which says there is iron-loving elements on the Moon surface, such as gold or platinum.
More than on Earth!

 

[glappkaeft]

I showed this with the example of uranium. I don't want to repeat this for every element, so why don't we go the opposite way? You find some element that is rare on Earth that can be easily mined on Moon in relevant amounts? With a reference to a space agency or other academic research, not to a company that wants to get funding for mining.

I agree. For instance in the (admittedly rather old) research papers I have seen the concentrations of the different Platinum Group Metals in M-class asteroids are stated to be in the 1-10 ppm range. That somewhat lower than the unsourced 50% number.

 

[mfb]

I came across this theory: "late veneer hypothesis"
http://www.nature.com/nature/journal/v520/n7548/full/nature14360.html
Which says there is iron-loving elements on the Moon surface, such as gold or platinum.
More than on Earth!

From the abstract: An excess of 27 ppm over the 64 ppm average of Earth. Which is tiny compared to the thousands of ppm found in tungsten ores on Earth.

 

[Al_]

From the abstract: An excess of 27 ppm over the 64 ppm average of Earth. Which is tiny compared to the thousands of ppm found in tungsten ores on Earth.

You compare this crustal concentration to ore concentrations.
Do you imagine that the Moon has 91 ppm evenly spread over it's entire crust?

 

[mfb]

You compare this crustal concentration to ore concentrations.
Do you imagine that the Moon has 91 ppm evenly spread over it's entire crust?

As long as you don't find any interesting element that has an interesting concentration anywhere on the surface: yes.

 

[Vanadium 50]

Do you imagine that the Moon has 91 ppm evenly spread over it's entire crust?

To a higher degree than on Earth, yes. Earth is geologically active and has an active chemistry going on on it's surface. The moon is not and does not.

Your messages defend wild speculation with more wild speculation, with a constantly shifting set of goalposts. You would more convincing if you used more facts.

 

[Al_]

To a higher degree than on Earth, yes

You claim that the Moon has a more even distribution of iron-loving elements over it's crust than Earth's distribution.
I find this to be speculative, since it's based on a few samples of very small size relative to the Moon.
You further assert that the Moon has no active geological processes. It has few. However it was geologically active in the past, not all concentrating processes require volatiles, and the results of that activity will now be frozen into place.
My posts do not consist entirely of wild speculation.


A quote from near the end of the abstract in the link -
"Low lunar HSE abundances are consistent with proportionally 40 times more late accretion to Earth than the Moon." - http://www.sciencedirect.com/science/article/pii/S0012821X15002903
This seems surprising, given that the Earth and the Moon inhabit the same region of the Solar System. (Even after considering that the Earth has a greater mass per surface area, about 6.2 times)
Isn't a more likely explanation that the Earth's mantle has been mixed since planetary cooling, whereas the Moon's has not, so that late accretions on the Moon remain highly localised, and so have not yet been sampled?

 

[mfb]

I find this to be speculative, since it's based on a few samples of very small size relative to the Moon.

All data (ground samples and from orbit), all references found in this thread, and all we know about geology of the Moon point to a consistent picture. You call that speculative.
We don't have any evidence for significant accumulations of specific interesting elements, yet you keep claiming that those would exist. And you don't think that is speculative?

Mines on Earth use hundreds to tens of thousand times higher concentrations than the average. The geochemical processes accumulating the elements are much more important than processes distributing them.

A quote from near the end of the abstract in the link -
"Low lunar HSE abundances are consistent with proportionally 40 times more late accretion to Earth than the Moon." - http://www.sciencedirect.com/science/article/pii/S0012821X15002903

The keyword is low lunar abundance.
Earth accumulated much more simply because it has larger mass.

 

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Someone not talked about as far as I can ascertain is Jeff Bezos. Contrary to Elon Musk, Jeff Bezos (Blue Origin) thinks the best way to Mars is via the Moon. His first long term goal is to help (with NASA) establish a human manned base on the moon. To that end he intents to launch a cargo capsules to the moon by the mid 2020's.(Operation Blue Moon) with manned flight sometimes after that. Blue Origin won the Aviation Weeks space Laureate Award for demonstrating true reusability of it's rocket without pulling the BE-3 engine for five consecutive launches.

The interview of Bezos at the award ceremony.


Bezos is working on a Mars trip with the development of the New Armstrong rocket.

Unlike Elon Musk Bezos is much less daring. Blue Origen's motto is "Gradatim Ferociter",i.e., "Step by Step, Ferociously".

 

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Blue Origin also released some more details about its rocket today. Article
The payload with the 2-stage variant will be a bit lower than FH, with the 3-stage variant I would expect it to be a bit higher.
The first stage is supposed to land on a ship and be reused up to 100 times.
Maiden flight not earlier than late 2019.

ULA with Vulcan and Arianespace with Ariane 6 are thinking about methods to recover the engine and other key parts of the first stage (but not the whole first stage). The race to reusable rockets is in full swing. I expect them to dominate the launch market in the 5-50 ton (LEO) payload range soon.