To Terraform or not to Terraform?

[Gawdzilla Sama]

I personally enjoy the idea of smacking Mars with a comet every 100 years or so. Good clean fun.

Each one is one less danger to Earth.

[mistermack]

I personally enjoy the idea of smacking Mars with a comet every 100 years or so. Good clean fun.

Each one is one less danger to Earth.

That is true. But I think if you could direct a comet at Mars, then you could direct it away from an Earth collision anyway.
I still reckon comets will be more use to man as they are in the space age.
They can be sources of materials to space vehicles that don't have to be lifted up out of the Earth's or Mars's gravitational pull, so they would be invaluable sources of water for propellant, and heavy elements for shielding space stations.
The water from a comet could be converted to fuel just using the power from solar panels. It would cost trillions to get that sort of quantity of fuel up into orbit normally.

[Gawdzilla Sama]

The water from a comet could be converted to fuel just using the power from solar panels. It would cost trillions to get that sort of quantity of fuel up into orbit normally.

Once they become impactors I'm certain they won't hit some place they're not welcome.

[mistermack]

The water from a comet could be converted to fuel just using the power from solar panels. It would cost trillions to get that sort of quantity of fuel up into orbit normally.

Once they become impactors I'm certain they won't hit some place they're not welcome.

You could maybe keep a little one back, and aim it at Kansas?
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[hackenslash]

I'd suggest pumping part of the atmosphere onto the ocean floor here and terraforming parts of this planet under the sea first. This would act as a test bed for technology without having to worry about expensive rocket fuel. And lets face it not much could go wrong compared with things as they stand already?

You might want to do some reading up on the problems faced by this. In reality, it's much cheaper and easier to explore space than it is to explore the deep.

[ScholasticSpastic]

I'd suggest pumping part of the atmosphere onto the ocean floor here and terraforming parts of this planet under the sea first. This would act as a test bed for technology without having to worry about expensive rocket fuel. And lets face it not much could go wrong compared with things as they stand already?

You might want to do some reading up on the problems faced by this. In reality, it's much cheaper and easier to explore space than it is to explore the deep.

Agree with . Space is a much less alien environment than the sea floor in many ways- especially considering that there is only a one atmosphere pressure difference between sea level and hard vacuum. The pressure difference between the sea surface and the sea floor is much greater. One is not a good model for the other.

[Gawdzilla Sama]

I'd suggest pumping part of the atmosphere onto the ocean floor here and terraforming parts of this planet under the sea first. This would act as a test bed for technology without having to worry about expensive rocket fuel. And lets face it not much could go wrong compared with things as they stand already?

You might want to do some reading up on the problems faced by this. In reality, it's much cheaper and easier to explore space than it is to explore the deep.

Agree with . Space is a much less alien environment than the sea floor in many ways- especially considering that there is only a one atmosphere pressure difference between sea level and hard vacuum. The pressure difference between the sea surface and the sea floor is much greater. One is not a good model for the other.

related.

[mistermack]

If a planet or moon had liquid water, you could make an inhabitable space underwater. All you need is 30M or less depth. You just choose the depth of water that gives one atmosphere of pressure. The water could be used to screen out harmful radiation as well.

[GreyICE]

Okay, so we could spend damn near infinite resources to terraform other planets, the bottom of the sea floor, etc.

Or you could use very finite resources, and cyborg and engineer humanity to be able to survive in those environments. What do you need to survive on Mars? Basic insulation upgrade, ability to scrubber CO2 to get oxygen, upgraded ability to absorb sunlight, remove some musculature? Seems easy enough compared to trying to terraform a planet.

[Gawdzilla Sama]

If a planet or moon had liquid water, you could make an inhabitable space underwater. All you need is 30M or less depth. You just choose the depth of water that gives one atmosphere of pressure. The water could be used to screen out harmful radiation as well.

Um, what's your point there? No free water on the Moon, nor Mars. And humans aren't designed to live underwater all the time. If you put up shelters, why not do that on the surface, they'd need less structural strength.

[mistermack]

If a planet or moon had liquid water, you could make an inhabitable space underwater. All you need is 30M or less depth. You just choose the depth of water that gives one atmosphere of pressure. The water could be used to screen out harmful radiation as well.

Um, what's your point there? No free water on the Moon, nor Mars. And humans aren't designed to live underwater all the time. If you put up shelters, why not do that on the surface, they'd need less structural strength.

Plenty of frozen water on mars. Plenty of solar energy so you could melt it.
And if you put up shelters on the surface, they would need great structural strength, because you would have one atmosphere of pressure inside, and nearly nil outside.
That's I kg per square centimetre. Ten metric tons per sq metre?
If you made your shelter under water, you could have I atmosphere inside, and water pressure of I atmosphere above, making zero effective loading.
The real problems would be keeping it from freezing, and maintaining stable conditions.
Anyway, it's a way of living there, but it's not terraforming by any stretch of the imagination.
It might be easier to live in a huge space station, orbiting Mars, and just operate machinery remotely by radio signals.
You can simulate 1g of gravity by spinning a space station fast enough to give 1g of centrifugal acceleration.
With that and one atmosphere of pressure, humans could probably live for long periods in space without health problems. ( so long as you have shielding against cosmic radiation and solar flares ).

[Gawdzilla Sama]

If a planet or moon had liquid water, you could make an inhabitable space underwater. All you need is 30M or less depth. You just choose the depth of water that gives one atmosphere of pressure. The water could be used to screen out harmful radiation as well.

Um, what's your point there? No free water on the Moon, nor Mars. And humans aren't designed to live underwater all the time. If you put up shelters, why not do that on the surface, they'd need less structural strength.

Plenty of frozen water on mars. Plenty of solar energy so you could melt it.
And if you put up shelters on the surface, they would need great structural strength, because you would have one atmosphere of pressure inside, and nearly nil outside.
That's I kg per square centimetre. Ten metric tons per sq metre?
If you made your shelter under water, you could have I atmosphere inside, and water pressure of I atmosphere above, making zero effective loading.
The real problems would be keeping it from freezing, and maintaining stable conditions.
Anyway, it's a way of living there, but it's not terraforming by any stretch of the imagination.
It might be easier to live in a huge space station, orbiting Mars, and just operate machinery remotely by radio signals.
You can simulate 1g of gravity by spinning a space station fast enough to give 1g of centrifugal acceleration.
With that and one atmosphere of pressure, humans could probably live for long periods in space without health problems. ( so long as you have shielding against cosmic radiation and solar flares ).

mistermack, you can melt the ice, but you can't keep it melted until the ambient temperature is above freezing.

And humans don't need one atmosphere of pressure.

[mistermack]

mistermack, you can melt the ice, but you can't keep it melted until the ambient temperature is above freezing.

And humans don't need one atmosphere of pressure.

You would of course need good insulation. and a reliable energy source. But insulation becomes much more efficient, the bigger the volume you are insulating. It might be a problem though, as air is involved in most insulating materials here on earth. But maybe a near-vacuum is also a good thermal insulator?
I have to admit I don't know, but I would have thought that very low pressures would really enhance the efficiency of thermal insulation. On the basis that you need something tangible to conduct the heat, and a perfect vacuum would not conduct any heat.

As far as pressures go, I don't know what pressures they work with on the space station, but many people get sick quickly at altitudes of over three thousand metres, which has roughly 0.7 of an atmosphere. So living with pressures less than that would normally be risky for all but Tibetans and Andeans.
Maybe you could compensate by putting more oxygen in the mix, but it would be quite a fire hazard. And you would have to be sure there was no long-term ill effect to health.
I would have thought that you would aim at re-creating earth conditions as accurately as possible, for long-term health.

Another thought occurs to me : To create a pressure of I atmosphere, you would probably need a depth of about 100 meters on Mars, as the gravity is so much less than here on Earth. But that might not be a bad thing, if you were using the water to filter out harmful radiation.

But to Terraform Mars, to recreate one atmosphere pressure, you would need two or three times the depth of atmosphere that we have on Earth, because the pull of gravity is so much less.
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[Gawdzilla Sama]

Overly complex.

And, btw, you can reduce the nitrogen in the mix by about 70%. Altitude sickness is a function of low oxygen, not low pressure.

[mistermack]

Overly complex.

And, btw, you can reduce the nitrogen in the mix by about 70%. Altitude sickness is a function of low oxygen, not low pressure.

Yeh, but I said that. If you lower the nitrogen, you raise the oxygen.
You would be living in a fire hazard, and it might be harmful long term.
And evaporation from the lungs would be much faster at low pressures, which might make you sick, even if you did drink more.