Why colonize Mars and not the Moon?

[Drakkith]

I don't think anyone thought the clause was to be taken literally.

I did. Perhaps erroneously.

 

[Aditya Shende]

Interestingly, regolith would be very well suited to surface mining (more like ploughing) with various methods of separating the various component parts. Separation by magnetisation, by size, by density. Lack of atmosphere would mean dealing with the dust could be done by panning methods. On the whole, it could be much more convenient than it is on Earth - at least for the first pickings. Then there's no NIMBYs and no sacred sites or sites of special Scientific interest.

You ain't getting the problem.
Ok ,
Consider it like this ,
On Earth there's dust everywhere it's in the air .
In the same way on moon there's dust everywhere the only difference is that the lunar dust has got SPIKES on it.

Dust on Earth has been jostled about by wind and water, rounding off the sharp corners.
While the Lunar dust has sharp edges, very abrasive because there's no water and lack of winds to wear off the edges. This poses a problem because it gets into moving parts and causes problems.
It also messes up seals to keep enclosures airtight.

So about mining and stuff that you are talking about won't work coz the mining , separating equipments ,etc have got moving parts and regolith messes up with them it doesn't matter if you try to keep moving parts sealed .
It still would mess them up (as I said above).
So, I don't think it's going to work.

PS: the moon doesn't lack atmosphere
It actually has an atmosphere that's
why there's lunar dust.

 

[Drakkith]

So about mining and stuff that you are talking about won't work coz the mining , separating equipments ,etc have got moving parts and regolith messes up with them it doesn't matter if you try to keep moving parts sealed .
It still would mess them up (as I said above).
So, I don't think it's going to work.

While certainly an obstacle, I doubt a little spiky sand is a obstacle that cannot be overcome.

 

[Aditya Shende]

While certainly an obstacle, I doubt a little spiky sand is a obstacle that cannot be overcome.

Well it's not just a little spiky sand
It's a 20 m thick layer of regolith
It's the churned form of
iron+ silicon+ Manganese+ Magnesium+ calcium+ aluminum+titanium+ glass
That's a lot deadly things churned up
And it's all spread in the atmosphere of the moon
It's in the air
Probably yes
It can be overcome
But still moon isn't a place suitable for colonizing
Building a space station on moon?
Great idea
But colonizing on moon
Not such a great idea

 

[Drakkith]

Well it's not just a little spiky sand
It's a 20 m thick layer of regolith
And it's all spread in the atmosphere of the moon

Estimates place the total mass of the dust in the 'atmosphere' of the Moon at 120 kg. This is an extremely small amount of dust and is unlikely to cause significant issues. The dust in the regolith is a much larger problem, but I see little reason to believe dust is a major inhibitor in colonizing the Moon.

 

[Aditya Shende]

Estimates place the total mass of the dust in the 'atmosphere' of the Moon at 120 kg. This is an extremely small amount of dust and is unlikely to cause significant issues. The dust in the regolith is a much larger problem, but I see little reason to believe dust is a major inhibitor in colonizing the Moon.

Yep
Ok
I just said
It isn't impossible to overcome this problem
But colonizing moon ain't such a good idea
Building a space station on moon=great

Colonizing on moon = not so great

Colonizing on Mars= great

 

[sophiecentaur]

It's in the air

What is in what "air"?
Compare the way a 'cloud' of dust behaves on Earth and how the dust from the wheels of the Lunar Rover behaves in that famous film.
You may not like the idea of colonising the Moon (I rather share your opinion on that) but I really don't think that the mineral gathering technology would need to be all that different from what's used in deep mining on earth. The dust and shards in a mine haven't been weathered; they've only just been exposed.
But, as usual, we haven't defined what we mean by 'a Colony'. Any station on the Moon would not be a holiday camp and only a minimum of human staff would be needed. (The management would all be tucked up in their posh ranches on Earth). How many staff does it take to make a 'colony'?
For Mars, the cost of transport is so much higher that staff would need to be there for much longer; long enough to breed? That would be one definition of a colony. We would be talking in terms of hundreds of colonists. Ye gods, there go all my taxes.

 

[Al_]

The surface of the Moon has been subject to billions of years of collisions with uncountable space rocks

Yes, exactly. It's those rocks themselves that bring the Iron. Some of them are Iron meteorites.

It's 20 metres thick

What, everywhere? Can you provide a reference?

But, as usual, we haven't defined what we mean by 'a Colony'.

Can I suggest a definition: People go to stay, and have children. Enough of them so the children can stay and have families.

Colonizing on moon = not so great

Why? I just don't get this. Sure, Mars looks prettier, and it has a kinder day/night cycle.
But the Moon should be first, because it would be much quicker, and it gives a really useful platform to go further and more easily.
What we learn on the Moon is very likely to be useful elsewhere, and it's material resources too.
Mars is down a deep gravity well. So, in the Solar System's economy of the 22nd century, it will be an isolated backwater compared to the asteroids, trojans, rings and small moons.

For Mars, the cost of transport is so much higher that staff would need to be there for much longer; long enough to breed? That would be one definition of a colony. We would be talking in terms of hundreds of colonists. Ye gods, there go all my taxes.

Elon Musk's idea is that it would be self-funding. He might even be right!
"Need to be there" you say? Like it's an difficult mission? Can't wait to get home?
Imagine, you're on the Moon. You are making a fortune from precious metals, TV rights sales, comms, etc. You buy architect services and robots from Earth and they build you a palace with gardens, pools, low-g sports gym, etc. Now, want to go home?
If Elon does start to offer tickets I will be looking for the Lunar Return prices!

 

[sophiecentaur]

Yes, exactly. It's those rocks themselves that bring the Iron. Some of them are Iron meteorites.

This all puts me in mind of the way 'they' extract gold from sediments. They go over the same river bed time and time again, squeezing harder every pass as the particles get smaller and the cost per gram goes up. Most of the Moon's surface is the equivalent to this river bed. No need to drill for a long long time.

 

[Al_]

This poses a problem because it gets into moving parts and causes problems.
It also messes up seals to keep enclosures airtight.

This problem has been solved.
Rotary seals like those used on Curiosity's wonky-looking arm are excellent at keeping out the most abrasive dust.
The seal itself can be made of an extremely hard ceramic. As it rotates it sheds any trapped particles outward from the axis, and at the same time grinds its surfaces flatter and closer together so they fit better over time.
The airlocks can use the same sealing method. And on the inner airlock door you can clean with gas before sealing.

 

[Aditya Shende]

What is in what "air"?
Compare the way a 'cloud' of dust behaves on Earth and how the dust from the wheels of the Lunar Rover behaves in that famous film.
You may not like the idea of colonising the Moon (I rather share your opinion on that) but I really don't think that the mineral gathering technology would need to be all that different from what's used in deep mining on earth. The dust and shards in a mine haven't been weathered; they've only just been exposed.
But, as usual, we haven't defined what we mean by 'a Colony'. Any station on the Moon would not be a holiday camp and only a minimum of human staff would be needed. (The management would all be tucked up in their posh ranches on Earth). How many staff does it take to make a 'colony'?
For Mars, the cost of transport is so much higher that staff would need to be there for much longer; long enough to breed? That would be one definition of a colony. We would be talking in terms of hundreds of colonists. Ye gods, there go all my taxes.

At least someone shares my opinion [emoji28]

 

[sophiecentaur]

At least someone shares my opinion [emoji28]

Only about the principle - not about the problems that you foresee about mining on the Moon.

 

[Aditya Shende]

Yes, exactly. It's those rocks themselves that bring the Iron. Some of them are Iron meteorites.What, everywhere? Can you provide a reference?Can I suggest a definition: People go to stay, and have children. Enough of them so the children can stay and have families.Why? I just don't get this. Sure, Mars looks prettier, and it has a kinder day/night cycle.
But the Moon should be first, because it would be much quicker, and it gives a really useful platform to go further and more easily.
What we learn on the Moon is very likely to be useful elsewhere, and it's material resources too.
Mars is down a deep gravity well. So, in the Solar System's economy of the 22nd century, it will be an isolated backwater compared to the asteroids, trojans, rings and small moons.Elon Musk's idea is that it would be self-funding. He might even be right!
"Need to be there" you say? Like it's an difficult mission? Can't wait to get home?
Imagine, you're on the Moon. You are making a fortune from precious metals, TV rights sales, comms, etc. You buy architect services and robots from Earth and they build you a palace with gardens, pools, low-g sports gym, etc. Now, want to go home?
If Elon does start to offer tickets I will be looking for the Lunar Return prices!

No
The moon is still not the place where we should set up our colonies
We know that the moon saves Earth from so many asteroid and space rock impacts
Just think
If such a space rock or asteroid hits the colony?
Still think moon is a better place to colonize than Mars
Answer: a)yes if the colonists want to die anyway
b)No if the colonists want to live
I would ho with b)

Only about the principle - not about the problems that you foresee about mining on the Moon.

Yes I got that
In 2 of my previous posts I said
'It's not a problem that we cannot overcome'
The thing is that
Moon is just not the right place to be colonized

 

[Al_]

We know that the moon saves Earth from so many asteroid and space rock impacts
Just think
If such a space rock or asteroid hits the colony?

The larger asteroids are very, very rare. They don't hit the Moon so much more often than they hit Earth. The smaller ones are not a problem if you live below metres of lunar regolith.
Even on Earth the large ones are a risk.
You can put enough regolith overhead to make the asteroid risk on the Moon the same as the risk on Earth.
Nothing and nowhere is zero risk.

 

[Aditya Shende]

Alright forget about the place for colonization (we both are never going to end up on a solution[emoji28])
We talked about ways to set up colonies like mining ,etc
What do you guys think about Terraforming ?

(Terraforming : Terraforming of a planet or moon, or other body is the process of deliberately modifying its atmosphere, temperature, surface, geology or ecology to be similar to the environment of Earth to make it habitable by Earth-like life.)

 

[Al_]

I did. Perhaps erroneously.

I meant it as an ideal case, picking the low-hanging fruit so to speak.
Given that we can spot pure Iron from orbit using spectral analysis, when we send the robot to pick it up, a magnet will probably work very nicely. Both for the main lump and some others that might be just below the surface.
Of course, later on, when scaling up the mining using less targeted methods, raking through acres of regolith, you may need to adapt this.

 

[Al_]

What do you guys think about Terraforming ?

I think that's a different thread!

 

[Aditya Shende]

I think that's a different thread!

Well let's talk about it here

 

[DrClaude]

Well let's talk about it here

No. Do not derail this thread with this off-topic subject.

Warning: threads on terraforming usually have a very short half-life because there is not much science and much speculation in them.

 

[Aditya Shende]

No. Do not derail this thread with this off-topic subject.

Warning: threads on terraforming usually have a very short half-life because there is not much science and much speculation in them.

Ok sorry
I am new to PF

 

[mfb]

You can put enough regolith overhead to make the asteroid risk on the Moon the same as the risk on Earth.

I don't think that is practical. The atmosphere protects nicely against objects up to ~10 meters, and reduces the effects of a direct impact even above that size. On the moon, we would probably need more than 100 meters of rock to get a similar protection.
I don't think it is necessary either. Impacts of meter-sized objects are extremely rare. Earth is hit by about one object with 4 meters diameter per year. Moon would get hit by at most 10% that rate (conservative upper limit), the probability that such an object hits a large 1 square kilometer installation directly is 3*10^-8, for an expected impact once every 300 million years. Objects with 1 meter diameter are probably more frequent by a factor 20-30, for an expected impact once every 10 million years - still completely negligible. Due to the lack of relevant atmosphere, an impact elsewhere would just generate some seismic waves and a few rocks and dust particles thrown around - for a meter-sized object this is completely irrelevant.

 

[1oldman2]

On the subject of Meteorite impacts I came across this recently, illustrates rather nicely the effects on a body with atmosphere, an advantage the moon lacks. (This is a very recent impact)
From, https://www.nasa.gov/image-feature/jpl/pia21451/unlocking-an-impact-craters-clues
"Mars is a dynamic planet. HiRISE has witnessed many surface changes over the past ten years, including hundreds of new craters formed by ongoing impacts. Most of these impacts are likely caused by asteroids that have strayed into collision courses with Mars. The planet's much thinner atmosphere compared to Earth makes small asteroids less likely to burn up prior to hitting the Martian surface.

This new impact was discovered using the lower-resolution Context Camera (CTX), also on board Mars Reconnaissance Orbiter. An older CTX image of this region from May 2012 shows a uniformly dust-covered surface, while a newer CTX image from September 2016 reveals the crater's dark blast zone. New craters on Mars are easiest to locate in such dust-coated terrains, where they provide opportunistic "road cuts" that allow scientists to see beneath the dust blanket and determine the underlying rock compositions and textures."

 

[Al_]

I don't think that is practical.

100 metres is a lot of dirt to dig. But a robot could do it I'm sure!
Or you could be in a cave or a mine.

 

[Al_]

2. LLO (or space elevator counterweight) to highly eccentric Earth orbit. On Earth approach, release the payload, then raise the perigee enough to avoid the atmosphere.

Great!
But are you sure that an unguided payload can hit the rght part of a desert if it's released into a fast, eccentric, grazing trajectory?
If it can, you nailed it!

 

[rootone]

I guess it could be arranged that the delivery capsule does have limited guidance which would home into a beacon on the ground.
It wouldn't matter if accuracy was only within 1 or 2 km.

 

[mfb]

Great!
But are you sure that an unguided payload can hit the rght part of a desert if it's released into a fast, eccentric, grazing trajectory?
If it can, you nailed it!

A release from an eccentric orbit makes a steeper re-entry trajectory easier compared to re-entry from LEO, which reduces the size of the landing ellipse. Aim for some desert.

 

[chasrob]

Yep
Ok
I just said
It isn't impossible to overcome this problem
But colonizing moon ain't such a good idea
Building a space station on moon=great

Colonizing on moon = not so great

Colonizing on Mars= great

How about the dust on Mars?

 

[sophiecentaur]

Even on Earth the large ones are a risk.

And the risk is so much higher for 'someone' getting hit on Earth because the density of population is so much higher. I would imagine that the structure of any living space on the moon (or Mars) would have very few large pressurised cavities and there would be safety shutters between all of them.

 

[Aditya Shende]

How about the dust on Mars?

Dust on Mars isn't regolith

 

[Al_]

I guess it could be arranged that the delivery capsule does have limited guidance

Well, I'm trying to envisage a method for regular delivery of precious metal payloads from the Moon that does not require much, or any, regular launches from Earth. (Because those are expensive)
If we can manufacture the guidance devices on the Moon, fine, but this was intended to be done in the early stages of Lunar colonisation.
No matter, we seem to have agreed that it's not needed.

A spin-off thought here: What would be economically viable for a space colony to purchase from Earth?
Cheapest is brainpower! That can be transmitted upward at nearly zero cost. This includes engineering designs and architecture as well as remote control of robots.(Remote control of robots works a lot better if they are on the Moon with a second or so time lag, rather than the long half hour-ish for Mars.)
Next is anything small and light, that takes a lot of infrastructure to make. e.g. raw unmounted silicon chips as well as precision components like valves and scientific instruments and sensors.

 

[nikkkom]

Well, I'm trying to envisage a method for regular delivery of precious metal payloads from the Moon that does not require much, or any, regular launches from Earth. (Because those are expensive)
If we can manufacture the guidance devices on the Moon, fine, but this was intended to be done in the early stages of Lunar colonisation

Depends on how you define "early". As I see it, for the first 100 years or so of the colony, any material goods from the Moon will be uneconomical to export to Earth.
One thing which _can_ be exported at a profit are souvenirs. "Buy our Moon rocks!", "This sapphire was grown from Moon's aluminium oxide!", "This titanium coin was made from the material of the fuel tank of the actual Moon descent stage". But the market for these is not that big.

 

[Al_]

Dust on Mars isn't regolith

Dust on Mars is potentially problematic in it's own way.
It is partly perchlorates, which have a corrosive effect like an alkali.

As I see it, for the first 100 years or so of the colony, any material goods from the Moon will be uneconomical to export to Earth.

Even Platinum?

 

[mfb]

Dust on Mars isn't regolith

It is. Or, to be more precise, the surface is covered in regolith, the smaller grains in it can become dust. Here is a discussion of how to reproduce it on Earth.
Regolith exists on Earth as well.

 

[Aditya Shende]

Dust on Mars is potentially problematic in it's own way.
It is partly perchlorates, which have a corrosive effect like an alkali.Even Platinum?

Didn't know that[emoji106]

 

[lifeonmercury]

The dust on Mars seems like a real nuisance. What if a patch of Martian ground was watered and covered with fertilizer. Would any plants be able to grow there?

 

[nikkkom]

>> As I see it, for the first 100 years or so of the colony, any material goods from the Moon will be uneconomical to export to Earth.

Even Platinum?

Yes, even Platinum. I don't understand your fixation on expensive metals. They cost a lot because they are rare. *And they are rare on the Moon too*. There are no places with platinum bars just lying on the surface, waiting to be picked up for free.

Even if (not proven) there can be locations on the Moon with somewhat more Platinum than in Earth platinum deposits, it will still need to be mined - and that costs money. In "early" colony, mining on the Moon is more expensive than mining on Earth, because infrastructure is not there, or insufficiently developed.

 

[rootone]

The dust on Mars seems like a real nuisance. What if a patch of Martian ground was watered and covered with fertilizer. Would any plants be able to grow there?

Plants definitely don't like perchlorates, it;s a bit like bleach, your topsoil layer would need to be separated from the martian soil,
so in effect your aren't using Mars soil, just replacing it with more plant friendly earth-like soil.
Where is the fertilizer to come from anyway?, other than recycled organic waste made from supplies originally shipped from Earth.

 

[nikkkom]

Nitrogen fertilizers can be made from atmosphere.

 

[Al_]

What if a patch of Martian ground was watered and covered with fertilizer. Would any plants be able to grow there?

On Earth, there are common organisms in soil that convert perchorates into harmless chemicals.
Presumably on Mars you would mix old soil that had plenty of these bugs with new regolith and dust, and organic matter, as a kind of composting process before it was used for plants.

There are no places with platinum bars just lying on the surface, waiting to be picked up for free.

Nuggets.

 

[lifeonmercury]

Plants definitely don't like perchlorates, it;s a bit like bleach, your topsoil layer would need to be separated from the martian soil.

The concept of growing plants on other planets is an interesting one. Let's say that some good potting soil is brought from Earth to Mars. Assuming this soil (and not any Martian soil) is used and the required water and fertilizer are provided... Are there any plants, shrubs, weeds, or algae that could survive outside somewhere on Mars?

 

[Al_]

Are there any plants, shrubs, weeds, or algae that could survive outside somewhere on Mars?

In a frozen state some things might. Some lichens seem to have survived a Mars-climate test, but i don't think they grew during the test. You mention green plants, and for them you need liquid water, without too much salt or perchlorate, above freezing point. At the lowest point on Mars (Hellas Basin) in the deepest crater, you just get enough pressure to stop pure water boiling away. Where would the water your plants need come from? But it might be very dry so even if it didn't boil, water would evaporate very quickly. I suppose if, at that spot, you had an unpressurised greenhouse, to keep the salt and perchlorate out and the water vapour in, and you got water from somewhere...

I don't understand your fixation on expensive metals.

- trying to argue that a Moon colony could sell stuff to Earth much earlier in it's growth than a Mars colony, and so be less draining on Earth budgets, and grow faster. And be less likely to fail!

 

[ian127]

Elon is the boy! Parachute rockets ,electric cars, asteroid colonies on Mars - who knows what he would come up with if terrorists kidnapped him to build them a missile?

 

[lifeonmercury]

Elon is the boy! Parachute rockets ,electric cars, asteroid colonies on Mars - who knows what he would come up with if terrorists kidnapped him to build them a missile?

Then we'd have ISIS to deal with on Mars. Not good.

 

[Karlms]

Seems to me like we should first build a base on the moon with robots, and then do the same on Mars. I don't see any point in planning to put humans on Mars as long as doing so would essentially be a suicide mission.

 

[mheslep]

Im having difficulty justifying the extinction event rationale used to start this thread. Most disaster scenarios I consider don't have a Mars Colony as the best survival strategy. Better survival scenarios can be found on Earth it seems to me, or a Mars Colony likely offers no better outcome.

1. 100% lethal plague? How does a Mars Colony help, unless all Earth-Mars travel is banned, permanently, shortly after a colony is established? Same problem applies for killer AI, worse in fact, as all data transfers also wound need to be banned. A killer plague (or AI) would need a very long incubation period to infect the total population before notice and contagion defeating quarantines are set. That same long incubation allows the plague to travel to Mars aboard a host.
2. K-T event like Earth impact. Surely constructing long term subterranean shelters on Earth are more feasible, and predictable, than the effort required for a sustainable Martian colony, which BTW is also likely going to be partially subterranean (radiation).
3. Killer solar event. Surely these are still more survivable, if at all, under Earth's atmosphere and magnetic field than at 1.5 AU and half the flux, though with a thousand times less atmosphere and nill magnetic field. Same goes for any extra solar system radiation event.

 

[rootone]

4. Greenhouse catastrophe, but then even fixing that is probably easier than trying to modify a habitat which didn't support life in the place.

 

[mfb]

@mheslep: We discussed this before. Making us more resilient to extinction is a nice feature, but I don't think it is the reason to go.

Concerning plagues: Diseases can spread in weeks. SARS had an incubation period of just a few days, but managed to spread to ~30 countries. The same disease with an incubation period of a month could have been a massive global catastrophe. Not enough to eradicate all humans, but enough to lead to serious trouble everywhere.

I'm not sure how well shelters survive a massive asteroid impact.

Solar events are directed - they can hit Earth or Mars, but not both at the same time. But they won't lead to extinction anyway.

 

[mheslep]

@mheslep Making us more resilient to extinction is a nice feature, but I don't think it is the reason to go..

Agreed

 

[Al_]

There is also the threat of nuclear war. It's debatable whether this could cause extinction, but I wouldn't like to bet on it.
A space colony could, if it is developed enough, be more robust in the face of such attack, harder to reach, and less of a priority target. A Mars colony is less vulnerable than a Moon colony.

As for disease, the sealed habitats in space are already perfect for quarantine, even if the bugs made it there with human travellers. I take the point about 100% lethal needing long gestation, but if plague combines with collapse of law and order, or war, it could lead to extinction even without 100% fatality from disease. Again, the longer trip to Mars means that a disease is more likely to be evident during the voyage, so Mars wins here too.

Having said that, a Moon colony offers substantial defences, and it would be a good stepping stone to even more protected places further away.

I think that extinction events are a good reason to go.
I know that such natural events are very rare, but given that we would want to go eventually to avoid an event, why not go sooner rather than later?
And man-made extinction events, how rare are they? Who knows? We could just sit on Earth and wait to see...

 

[mheslep]

...be more robust in the face of such attack, harder to reach

In the age of a Martian Colony and frequent heavy manned missions to/from Mars, sending a couple unmanned tons that don't land to Mars becomes trivial for some malevolent actor in power. Even today's Falcon 9 FT can deliver four tons to Mars, or multiple thermo nuclear weapons. Any hardened shelter on Mars can be done better and more efficiently on Earth.