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#51 2020-07-11 12:52:13

Void
Member
Registered: 2011-12-29
Posts: 3,710

Re: Is terraforming Mars impossible? Maybe not...

In my opinion, much of the water would stay up there.   As it is, it "May" take micrometeorites to seed clouds up there as it is.
https://www.foxnews.com/science/meteor- … ds-on-mars

So, water without grains to condense on, can exist as a vapor in a super cooled state.  And water vapor is very much lighter than the CO2 dominated Martian atmosphere.  So, and this is just my suspicion, I have been wrong many times before, you may overwhelm the number of grains available for condensation.   Wash the downwards perhaps.  Clean the atmosphere.

I like your thinking I hope you will tolerate what I am going to pass by you.

I have often thought about the energy of elevation.  An air molecule on top of the mountain has more energy than one at base level, in the sense of elevation.  So, if you thought of it as a weight, could you drop that weight to generate power?

If you compressed and condensed CO2 out of the Martian atmosphere, into a liquid, and had the means, could you run it down a mountain like hydro-electric?  I do not have the mental tools to answer this.  We do have an expense, that is condensing the CO2 into a liquid.  But it is probably darn cold at most times up on the top of Olympus Mons.  And particularly at night I am thinking.  But solar power is likely rather good.  It takes a really big global dust storm to blot it out.  And even then it is still probably cold.  Just a silly notion true.  However, if you have liquid CO2, then if you are passing this downward through a rock tunnel, then perhaps a bit of geothermal boiling?

But also, if you send the liquid CO2 all the way down the mountain, and it arrives as a liquid, you may boil it with solar or nuclear and run a turbine.  And there may be a way to condense water vapor with it as well.  I think these things from time to time.  If you were a dog, I would have just thrown you a chew toy.  Hope that's OK.

------

This one is a bit more trouble.  If you have heated Martian air and you flow it upwards through a conduit to the top of the mountain and it has water vapor in it, perhaps saturated???  What?  What might the pressure of the updraft be at the top of the mountain?  The flow rate.
Of course all of that will also depend on the size of your conduit, and how hot the air is. 

As I have said I do not even come close for the mental capability it takes to even try to get rough numbers.

We may consider Lava Tubes, sealed, and perhaps connected by boring tunnels, or on surface conduits.

I feel a bit like a jerk, doing this to you, but maybe you will accept it as some workout for yourself.

Done

Not done smile

If you do succeed in loading up the Martian atmosphere at levels useful, with extra water vapor, then I also want to look at a "Cloud Diode".

As I visualize this, water vapor even super cooled will be a greenhouse gas, perhaps in all of the skies of Mars.  But if you were really good at pumping vapor up there you may seed the clouds with grains, perhaps from a Martian moon.  And if you have the correct balance, you might just get the planet to generate a cloud deck more on it's dark side and less so where the sun shines.  If it is done right, the clouds may not descend all the way to the ground during the night, and may vaporize in the sunshine, and climb back up to the high skies.

The polar hoods of Martian winter suggest what this might be like.

https://en.wikipedia.org/wiki/Martian_p … ese%20look.
Quote:

Called the polar hood, the clouds drop precipitation which thickens the cap. The north polar cap is symmetrical around the pole and covers the surface down to about 60 degrees latitude. High resolution images taken with NASA's Mars Global Surveyor show that the northern polar cap is covered mainly by pits, cracks, small bumps and knobs that give it a cottage cheese look. The pits are spaced close together relative to the very different depressions in the south polar cap.

However, if we were to introduce some greenhouse gasses to the atmosphere of Mars, including water vapor, we might expect the Martian poles to heat up most.  If we do get the CO2 vaporized, and prohibit more dry ice forming, then we should have a atmosphere of a mean pressure of 11 mbar, rather than the 5.5 mbar we have now.

I have read, that that is enough for real snow storms.  In this case I am hoping that the snow would come more from vaporized polar water ice than from the water vapor we transferred to on high.

We would be basically be doing a Venus run-away-greenhouse effect to Mars,   But we should be able to modulate, and control the run-away.

If we could generate a Cloud Diode, that should help the dark side of the planet retain heat, and for the sunward side to accumulate heat.

But, Maybe smile

Done

Last edited by Void (2020-07-11 13:20:11)


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#52 2020-08-09 18:07:00

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 21,706

Re: Is terraforming Mars impossible? Maybe not...

A possible view
vc_ca101_nationalparks_lassenvolcanic_manzanitalake_rf_628846294_1280x640.jpg

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#53 2021-01-21 10:54:54

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 828

Re: Is terraforming Mars impossible? Maybe not...

This concept, at least in principle, suggests that very tall structures capable of reaching the ionosphere, are technically feasible of Mars.
https://www.ibtimes.com/space-elevator- … re-2058158

What I am proposing in this thread is somewhat different to the space elevator concept.  The elevator proposed here is 12.5 miles (20km) high.  I am proposing a terraforming tower with height some 4 times higher and built on the Olympus Mons caldera.

It would essentially be a hollow tube, with water pumped up the tube and sprayed into the ionosphere.  The water vapour would be dissociated by UV light, gradually giving rise to a pure oxygen atmosphere.  Without any weather on the top of Olympus Mons, the tower stability would be less of a problem.  To limit lateral movement, bracing cables would be attached at various points to the structure, anchoring it to the rim of the caldera.

The pressure at the bottom of a 100km high water column would be 375MPa on Mars.  So I would expect a staged pumping arrangement for the tower.  We could in fact use liquid CO2 to power gas lift pumps without moving parts.

A good question would be where to source the water from.  Craters indicate the ice does not exist beneath the surface of Mars at latitudes less than 40 degrees north.  However, groundwater may be present beneath 4km of rock.  This is a lot of drilling.  However, the rock pressure at this depth means that the water would not require pumping.  It would exit any well with substantial additional pressure.

Last edited by Calliban (2021-01-21 11:04:45)


Interested in space science, engineering and technology.

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#54 2021-01-21 11:23:12

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 828

Re: Is terraforming Mars impossible? Maybe not...

Void wrote:

If you compressed and condensed CO2 out of the Martian atmosphere, into a liquid, and had the means, could you run it down a mountain like hydro-electric?  I do not have the mental tools to answer this.  We do have an expense, that is condensing the CO2 into a liquid.  But it is probably darn cold at most times up on the top of Olympus Mons.  And particularly at night I am thinking.  But solar power is likely rather good.  It takes a really big global dust storm to blot it out.  And even then it is still probably cold.  Just a silly notion true.  However, if you have liquid CO2, then if you are passing this downward through a rock tunnel, then perhaps a bit of geothermal boiling?

Done

That is a novel idea.  And the temperature of the Martian atmosphere is close to the CO2 triple point (220K) so compressor work should be low.  Unfortunately, the low density of the atmosphere would require a large compressor for any particular flowrate.  The higher you go, the greater the pressure head of any liquid CO2 column and the more power you could generate.  But the thinner the atmosphere becomes and the bigger the compressor needs to be.

From what I have read though, there is likely to be liquid CO2 just a few tens of metres beneath the surface of Mars.  With a low grade heat source, really anything higher than 31C, this becomes supercritical CO2 gas.  Pressure could be anything up to several tens of MPa, so liquid CO2 pumped out of the ground, would be an excellent working fluid allowing very compared power generation turbines.  We would simply vent waste CO2 into the atmosphere.

My guess is that as Mars population increases, we will naturally increase the amount of CO2 in the atmosphere as we use it as an open cycle working fluid.  No need to deliberately warm the planet.  It will end up happening anyway, as humans access stored CO2, dump nuclear waste heat into the atmosphere and cover large areas of the planet agricultural domes and pipes.  Global warming would be an inevitable result of a populous human society on Mars.


Interested in space science, engineering and technology.

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#55 2021-01-21 11:25:12

tahanson43206
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Registered: 2018-04-27
Posts: 5,597

Re: Is terraforming Mars impossible? Maybe not...

For Calliban ... your post #53 reminds me of a tower discussion led by JoshNH4H

While your proposal is certainly different from what I remember of his, it still might be interesting for you to glance at the earlier work.

The weak gravity of Mars is a concern.  If humans ever get serious about terraforming the planet, adding enough mass to keep an atmosphere might be worth considering.

It seems to me your proposal would harness solar energy in two ways ... it would deliver Oxygen by separating it from Hydrogen, which would then waft off into space.  It would also use solar energy to lift the water to the top of the tower.

Best wishes for success with this idea! 

(th)

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#56 2021-01-21 18:39:20

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 21,706

Re: Is terraforming Mars impossible? Maybe not...

Mass would increase gravity on mars over time but not protection for the internal dynamo of earths core. Mars is not as large and does not have the convection going that one needs to get a field going....
Most want an earth like atmosphere and the question is with water can we get a current passing through if seeded with metals to repel atoms of the atmosphere from leaving the planet....

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#57 2021-01-22 03:48:26

Calliban
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From: Northern England, UK
Registered: 2019-08-18
Posts: 828

Re: Is terraforming Mars impossible? Maybe not...

Adding mass to Mars to increase its gravity in any meaningful way will be hopelessly impractical. The entire mass of the asteroid belt is only 4% of Lunar mass. That makes it about 0.5% of Mars mass. Not enough to make any difference.
Ganymede is only 2.5% of Earth's mass; Callisto about the same. The entire combined mass of the Jovian moons is about the same as the mass of Mars.

I did look into using water from Ceres as the feedstock for building an oxygen atmosphere for Mars. But the energy requirements are orders of magnitude greater than they would be if we used Martian surface water instead. A minimum breathable oxygen atmosphere on Mars would consume about 10% of the planet's known ice reserves. It is therefore achievable from a natural resource perspective.

To give some idea of how difficult it would be to create a 100mbar pure oxygen atmosphere: one must electrolyse or break down using sunlight, some 120,000 tonnes of water per second, for 100 years. And that assumes perfect efficiency. I don't know if Mars receives enough UV flux to do the job that quickly. But assuming it does, we would need to construct a lot of terraforming towers to ensure that the water vapour fully evaporates into the Martian upper atmosphere without precipitating.

I originally investigated carrying out electrolysis on the Martian surface. This could use solar, satellite solar or nuclear fusion as an energy source. But the energy requirements are huge. Electrolysis of 1kg of water take 15MJ of electrical energy. So 1kg/s is 15MW. To carry out electrolysis on 120,000 tonnes per second requires a power output of some 1.8million GW. That is the electrical output of 1million large nuclear reactors. It is also about 10% of the energy flux from the sun that intercepts the Martian surface. In other words, we would need to cover the entire temperate and equatorial regions of Mars with 20% efficient solar panels to provide enough power to get the job done in 100 years. Terrawatt scale fusion reactors may be a better bet. The bigger a fusion reactor is, the easier it becomes to reach the lawson criterion.

But the implications are clear. Creating a breathable atmosphere on Mars will only be possible if the planet is home to a civilisation with powers already greatly exceeding those of human society on Earth. Hence, Mars will have a population of billions before serious terraforming even starts.

All of our practical plans for Mars colonisation should aim to deal with the planet as it is.  Terraforming is for the distant future as far as we are concerned.

Last edited by Calliban (2021-01-22 04:12:14)


Interested in space science, engineering and technology.

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#58 2021-01-22 11:52:15

tahanson43206
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Registered: 2018-04-27
Posts: 5,597

Re: Is terraforming Mars impossible? Maybe not...

For Calliban re #57

I've been thinking about your discussion while working on the ID's. 

In earlier posts, I have offered the supposition that Mars is currently holding all the atmosphere it is capable of holding.

I don't ** know ** that is the case.  Perhaps there is some other reason the atmosphere is what it is.

Are you aware of any factors that would allow Mars to hold more atmosphere than it has?

For example, taking the Earth's atmosphere as a guide, the amount of CO2 generally reported (at present) is (about) .04% (per Google snippets).

If we were to take that as a model for an ideal breathing atmosphere on Mars, then we should be able to compute:

1) Given the amount of CO2 already present on Mars, then:
A: The amount of Oxygen that would represent 21% of an Earth equivalent atmosphere
B: The amount of Nitrogen (or other inert gas) that would represent the balance needed to mach the Earth's atmosphere.

2) Given the results of (1) then ...
A: The atmospheric pressure that would be experienced at the surface of Mars while the gases remained present ...
B: The amount of time the gases would remain before they are whisked away due to the low gravity of Mars.

This question set follows upon your premise in #57 that it is impractical to increase the solid mass of Mars.

(th)

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#59 2021-01-22 17:20:28

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 21,706

Re: Is terraforming Mars impossible? Maybe not...

This also fits with on the topic

SpaceNut wrote:

The reasons for Mars is that the solar winds can blow the atmospher at high altitudes away from the planet. The trailing wind behind the planets blocking of the suns energy then is pulled from it due to the gravity of the planet. The not having any radiational shielding belts to help with a static shield is the last for why Mars has so little air remaining.
Upper air heating is the enemy for planetary loss.

Mars losing its atmosphere at a faster rate

So mars needs several things to combat the rates or it going into space....

NASA proposes a magnetic shield to protect Mars' atmosphere (phys.org)

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#60 2021-03-30 15:48:25

Quaoar
Member
Registered: 2013-12-13
Posts: 591

Re: Is terraforming Mars impossible? Maybe not...

Terraforming Mars, if it's possible, would require thousand years. But before starting it we need to know if there's life or not. If there is life, I think it's wrong to disrupt an ecosystem. It would be better to leave Mars as it is and build orbital O'Neal's cylinder, which would have the right atmosphere and the right gravity for humans.

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#61 2021-03-30 17:51:02

Void
Member
Registered: 2011-12-29
Posts: 3,710

Re: Is terraforming Mars impossible? Maybe not...

------
I am fairly open minded about it.
I think that for Venus, it will be very easy to say yes or no life in the clouds, and then decide what is to be done if anything.
For Mars, it will likely require humans on the surface to find it and get samples, unless it has somehow adapted to the surface.  Perhaps on the surface, in the materials left behind by a glacier, evidence of it could be found, even if not alive.
So, to find it, and study it, perhaps humans must contaminate part of the planet.  But you said terraforming.  Well you might be right.  We have mostly left Antarctica as is for now, while studying the situation.  It might be that that is as far as we ever go with Mars, if what we find gives reason to take that sort of path.
At this point, I think that there could be several methods for life to get energy on Mars.  And aquifers that were not too toxic to life might be possible.  I actually think that experiments have shown that lichen can adapt and have metabolism in cracks in the rocks and soil.
So, anything like that will be important to study.  And there could be alternatives, such as in the Asteroids and the Moon.
We either live in a solar system where Panspermia operated and possibly left behind related life forms, or the universe is designed to spawn life in favorable situations.  Depending on the test results of examining that, then we might each form an opinion.
Things that I am rather intolerant of are people who feel that they can decide these things for the human race.  It is fine if they make their opinions known, but they are not the boss of us in my opinion.
As I have said before, the fate of any life on Mars might be changed in a positive or negative way by human activities.  Life in the Atacama desert, being extremely used to the dry, will often die if it rains.  However life that is deep down on Mars, might not even notice human activity very much, particularly if humans consider the situation and are carful to minimize the changes. 
However, Martian life as is may already be extinct, or on it's way to extinction.  Certainly Mars will not be even marginally habitable far in the future, and the Earth as well.  If Martian life were to travel with Earth life to another planet in another star system, then have humans done good or evil for it?  And might we show it the tree of life, at least in our actions done to it, in that factor?
So, I guess there is a lot of discovery both in science, and morality ahead of us.
------
If there is life or evidence of past life several places in the solar system,
1-It was aliens?
2-Natural panspermia.
3-Life springs from processes in the universe.
If there is life or evidence of past life in several places in the solar system, then we can suppose that life is all over this galaxy at least in the case of #1 & #3.
In the Case of #2, then only this solar system, but possibly all over.
So, as I believe Dr. Zubrin has said, valuing humans above microbes might be justified, especially if that valuing of humans, leaves the microbes a path to continuation of some sort.
Valuing microbes above humans is wrong.  However if the microbes have a unique nature, then that is possibly something of value that humans should work to preserve.
------
I think it highly likely that for an early Glacial Mars, it would have been easy for glacier adapted life to transfer between planets.  But Mars is much more variable many of those types of life may have gone extinct on Mars repeatedly.  But I think it is very probable that somewhere in the depths, something that has reasonable water, and Hydrogen from Radiolysis, has high chances of having persisted.
The question is if it lives in the deeps where the pressure is high, would it be so hard for it to tolerate terraforming?  Perhaps it would even prosper from it, as more of the deeps might become more habitable.
So, there are a lot of questions to ask and to get answers for.
But I agree, Orbital Habitats are going to be a big part of the future.  I think it is insane to not think about having them for Mars.
But all of this is only one persons opinion.
Done.

Last edited by Void (2021-03-30 17:52:18)


I like people who criticize angels dancing on a pinhead.  I also like it when angels dance on my pinhead.

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#62 2021-04-01 11:16:47

Quaoar
Member
Registered: 2013-12-13
Posts: 591

Re: Is terraforming Mars impossible? Maybe not...

Void wrote:

------

But I agree, Orbital Habitats are going to be a big part of the future.  I think it is insane to not think about having them for Mars.
But all of this is only one persons opinion.
Done.

A Mars habitat has to be built underground for radiation protection and to avoid meteoroid strikes

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