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Would it be ethically right to terraform Mars?
Yes 69%  69%  [ 9 ]
No 23%  23%  [ 3 ]
Don't know 8%  8%  [ 1 ]
Total votes : 13
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PostPosted: Mon Sep 06, 2010 8:46 pm 
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Wishful thinking that vastly underestimates how inhospitable Mars is.

Mars will never be terraform-able as most envision it (a synthetic Earth). It is simply to small, to cold, and its atmosphere to thin to ever support Terran biology. I doubt you'd even be able to gene-engineer something tough enough to function in that environment. The best we'll ever see are domed over craters and canyons to support imported life.


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PostPosted: Tue Sep 07, 2010 2:17 am 
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oh boy here we go again. another uneducated individual yapping. sorry james, mars is not too small. its land mass is equal to our own minus the oceans. secondly, why do you use the word terra forming when you do not understand what it means????? the term means to change a planet's atmosphere to our liking. not go there right now and choke on the carbon dioxide. we will build green house gas making machines/factories and thicken the atmosphere so it can hold in the heat.
hello??? it may not be the temperature on san diego, but it will be warm enough for us-again read the original article...centuries!!! not days.


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PostPosted: Tue Sep 07, 2010 3:33 am 
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Your opinion does not change the reality.

The planet is half the diameter and only 1/3rd the gravity of Earth.
That weak gravity means it can only hold onto 1/100th of the atmosphere. It is for all intents and practical puropses a vacuum.
In those conditions water boils off into vapor as soon as it melts, which doesn't happen often because...
It recieves two and a half times less energy from the sun than Earth.
And so its temperatures rarely exceed freezing.
Mars lacks any significant magnetic field so its atmosphere is constantly being robbed by the solar wind, and its surface hit by ultraviolet radiation.

Most of the greenhouse (or any other) gases you put in the Martian atmosphere will leak out into space as fast as you could produce it short of bombarding the planet with several large comets. But even then, it would eventually dissapate away because the planet does not have the gravity or magnetic field to hold onto it. The greenhouse heating will actually make things worse because it will inflate the atmosphere and accellerate the high altitude losses.

Sorry dude, its never gonna happen.


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PostPosted: Tue Sep 07, 2010 6:15 am 
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Never is a strong word. I think "unlikely in the near future" would be preferable. Keep in mind that flying in a machine heavier than air was long thought to be the pursuit of loonies. You are right that at the present it is almost entirely impossible, but technology changes. Perhaps it will never be suitable to life as we know it, but with developing fields in synthetic biology perhaps something could survive off completely different chemicals, something more like Titan's atmosphere. You are right that solar wind will present a problem for any potential planet engineers, and while I don't want to say it WILL happen, I also don't want to say it will NEVER happen. Keep an open mind, you might be pleasantly surprised one day. :)


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PostPosted: Tue Sep 07, 2010 2:31 pm 
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I suppose we could crash Ceres and the rest of the asteroid belt objects into Mars and that would do the trick.


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PostPosted: Wed Sep 08, 2010 8:27 am 
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This thread was originally about whether it would be right or wrong to terraform Mars. However, if that was literally impossible then discussing whether it was right or not to do it would be purely academic - so this is a relevant question.

I'm sure it's true that Mars' lower gravity and the solar wind would make it hard for it to hold onto an Earthlike atmosphere. However, the big question is if Mars was given an Earthlike atmosphere, how long would it take to leak away into space again? If the answer is a million years, or even a hundred thousand years - blinks of the eye in geological time - then terraforming it might still make sense. We simply don't operate on those timescales, and besides, a human colony on Mars might be able to top up the atmospheric losses from time to time. Even if the atmosphere would remain breathable for ten thousand years, that might be enough for the terraforming project to make sense.

How can we work this out?

JamesG wrote:
The planet is half the diameter and only 1/3rd the gravity of Earth.
That weak gravity means it can only hold onto 1/100th of the atmosphere. It is for all intents and practical puropses a vacuum.

It is for most intents and purposes a vacuum, but not all. Two exceptions that occur to me (there may be others):
1) It has enough atmosphere to generate fierce dust storms which actually make it a more hostile environment than it would otherwise be.
2) The current, thin Martian atmosphere is 95 percent carbon dioxide, whereas in the Earth's atmosphere only a fraction of a percent is carbon dioxide. This means that Mars actually has a greater pressure of carbon dioxide at its surface than the Earth. I'm not totally sure of the significance of that, if any, but thought I'd mention it!


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PostPosted: Wed Sep 08, 2010 9:20 am 
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Yeah sorry for getting a bit off topic there.
I'm not sure if anybody else has read it, but there's a book called Red Mars which centres around the first colonies on Mars and the whole trilogy is all about the terraforming of Mars. I am yet to read it, but it's on my bookshelf and as soon as I get through 'The Lost Symbol' I'll read it and tell you guys what Kim Stanley Robinson thinks about all this!


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PostPosted: Wed Sep 08, 2010 1:07 pm 
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RickLewis wrote:
This thread was originally about whether it would be right or wrong to terraform Mars. However, if that was literally impossible then discussing whether it was right or not to do it would be purely academic - so this is a relevant question.

From a purely academic perspective, the specific subject doesn't matter, be it Mars, the Moon, or New Jersey. Were it within out capabilities, it might be argued more fiercely. But even now, you could say that we are "terraforming" Mars by having strewn landers and other junk around and driven rovers across the surface digging holes and scuffing up rocks. So we have already modified the natural environment permanently.

But back off topic:

Quote:
I'm sure it's true that Mars' lower gravity and the solar wind would make it hard for it to hold onto an Earthlike atmosphere.


Not hard. Physically impossible.

Quote:
However, the big question is if Mars was given an Earthlike atmosphere, how long would it take to leak away into space again? If the answer is a million years, or even a hundred thousand years - blinks of the eye in geological time - then terraforming it might still make sense. We simply don't operate on those timescales,


The problem is that with our current technologies (or any chemical, non-catastrophic means), it would take us thousands of years to convert the atmosphere. So we would be on a fools errand of trying to fill a bucket with a hole in the bottom.


Quote:
1) It has enough atmosphere to generate fierce dust storms which actually make it a more hostile environment than it would otherwise be.


Hehe, those "fierce dust storms" would feel like a mild breeze on Earth. They are extremely subtle and only kick up dust because of Mars' weak gravity.

[/quote]
2) The current, thin Martian atmosphere is 95 percent carbon dioxide, whereas in the Earth's atmosphere only a fraction of a percent is carbon dioxide. This means that Mars actually has a greater pressure of carbon dioxide at its surface than the Earth. I'm not totally sure of the significance of that, if any, but thought I'd mention it![/quote]

Not much. One of the reasons Mars has even as much atmosphere as it does is that its mostly thick heavy CO2. If you try to split that into free O2 and find N2 somewhere to try to build a breathable atmosphere, it will leak out all the more faster.

I really hate to keep raining on the parade, but people really have been given some false assumptions by sci-fi books and movies, a few books by people with pretenses, and even NASA to degree, that really downplays just how dead Mars really is.


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PostPosted: Wed Sep 08, 2010 5:39 pm 
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JamesG wrote:
The problem is that with our current technologies (or any chemical, non-catastrophic means), it would take us thousands of years to convert the atmosphere. So we would be on a fools errand of trying to fill a bucket with a hole in the bottom.

You can fill up a bucket even with a hole in it if the leak through the hole in the bottom is slower than the flow of water into the top. The question I'm asking is: how bad is the leak?

JamesG wrote:
Not much. One of the reasons Mars has even as much atmosphere as it does is that its mostly thick heavy CO2. If you try to split that into free O2 and find N2 somewhere to try to build a breathable atmosphere, it will leak out all the more faster.

Actually I wasn't suggesting that we should try to create a breathable atmosphere by splitting the atmospheric CO2 on Mars. Plainly even if we converted all of it into carbon and oxygen that wouldn't create more than a minor fraction of the 02 needed anyway - even disregarding the leak! I suppose if I was suggesting any significance at all, it was for photosynthesis in plant life.

JamesG wrote:
I really hate to keep raining on the parade, but people really have been given some false assumptions by sci-fi books and movies, a few books by people with pretenses, and even NASA to degree, that really downplays just how dead Mars really is.

No, keep on raining! These are important questions.


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PostPosted: Wed Sep 15, 2010 11:31 pm 
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I've been trying to work out the size of the hole in the bucket - or in other words, how rapidly Mars would lose atmosphere. I can see it is probably a reasonably straightforward calculation but that it involves quite a few variables and may well be beyond my current abilities. (I'm a pretty rusty physicist!)

The best way to look at the problem might be to consider a cylindrical column of atmosphere extending upwards from the planet's surface. Consider any one of the constituent gases of the planet's atmosphere. For any given partial pressure of that gas at the surface, it should be possible to calculate the partial pressure at any altitude given (a) standard laws about the behaviour of gases; (b) the gravitational pull - which in the case of Mars is about 1/3 of that on Earth; (c) molecular mass of that gas.

I presume that the greater the gravitational pull, the more any given volume of gas in the column will tend to be concentrated at the bottom of the column. Therefore a given amount of (say) oxygen in the column on Earth will result in a greater partial pressure of 02 at the planet's surface than the same amount of oxygen in the same sized column on Mars. This is a pity as it means that creating the same partial pressure of 02 at the surface of Mars that we are used to on Earth would take a greater quantity of 02 in the column. We need more air on Mars in total to get the same amount of pressure at the surface. However, that still doesn't mean that it can't be done - only that it would take longer and be more expensive.

Within any given column of gas on Mars (or Earth) the pressure will of course be greatest at the bottom and decrease with increasing altitude. The solar wind will remove some of the gas from the upper parts of the column only. Ionizing radiation might reach the planet's surface unimpeded, but interactions between it and gas molecules near the surface aren't going to remove those molecules from the atmosphere. However, as the solar wind removes gas from the upper reaches of the column, of course the gas in the column will tend to redistribute upwards so that the pressure at the surface will also fall.

Therefore to calculate the rate of loss of 02 due to the solar wind on a terraformed Mars:

1) we assume a partial pressure of 02 at the surface of Mars equivalent to the partial pressure of 02 we are used to at the surface of the Earth.
2) we then calculate the partial pressure distribution in the upper parts of the column
3) we calculate the intensity of the solar wind at those altitudes
4) from this we can make some sort of calculation of the rate at which solar wind removes 02 from the Martian atmosphere.

However, doing the actual calculation is currently beyond me. Sorry.


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