OT: Carbon Dioxide races -> known vs unknown -> terraforming mars -> is or is not - Page 4

Loser · #31 July 16th, 2003, 07:14 PM

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Originally posted by Suicide Junkie:

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Maybe the pressure could be maintained at one earth atmosphere, with a mix of (say) 70% N2, ~26% O2, ~4% CO2.

That is dangerously close to a lethal atmosphere. Your colonists would suffer greatly, and casualties would be high.
Drop that CO2 concentration by at least an order or two of magnitude.

One important thing to remmeber is that CO2 is heavy. It will collect at the ground, where your people are trying to breathe.

Also, it is a 'greenhouse gas'. Too much or too litte of certain gases at certain distances from stars producing certain levels of heat will lead to planets too hot or too cold for life.

CO2 levels need to be low. There needs to be some, but not much. Not much at all.

Taera · #32 July 16th, 2003, 07:29 PM

i cant name the source but i remember reading that Mars has some nitrogen - in frozen state however, i think on the poles. Also plants alone cannot strive outside the nitrogen cycle as i think you also require animal/bacterial life for completing the cycle and that is a whole different issue.

I also think they found not-so-thin layer of CO2 which they said would be sufficient to maintain plant life. that is, /methinks.

If realy, why bother with mars? I've never understood it. Whats special about it? is it the closest planet to earth's conditions or what.

Loser · #33 July 16th, 2003, 07:51 PM

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Originally posted by Taera:
If realy, why bother with mars? I've never understood it. Whats special about it? is it the closest planet to earth's conditions or what.

Yes it is.

You-all ever hear about land probes on Venus? No? Well I'll tell you why.

I don't think U.S. has put anything over there, but the U.S.S.R. did. The best one Lasted a couple hours. The atmosphere is so caustic that it eats up whatever we drop over there.

Mercury is too dang hot, way to dang hot.

Luna is dead, dead, dead. And dry and just about useless.

Everything else is just too far away, though compared to terraforming Mars, getting to the Jovian satellites is no that big a deal.

Taera · #34 July 16th, 2003, 07:56 PM

how about Planet X?

we dont know that
but yea, i know than nothing before earth is any good, but if realy i know very little of the later planets in the solar system

Loser · #35 July 16th, 2003, 07:58 PM

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Originally posted by Taera:
i know very little of the later planets in the solar system

The outer planets are just too cold. No terraforming options out there.

Fyron · #36 July 16th, 2003, 08:46 PM

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Originally posted by Taera:
you're speaking of earth's chemistry and physics. You cannot claim that next solar system's physics arent different and that there are no other kinds of particles/elements there. there is a little too much "cannot" here because humans had not explored much outside the Earth. If realy, how can you know we wont find some unique element even deep in mars, in the asteroid belt or on Pluton?

Because matter is fundamentally ordered. It can not exist in bizarre new combinations, for all stable combinations exist on earth (naturally or in labs). Except, of course, those theorized stable 180 proton elements (anything past 118 or so (or is it 124?) is highly unstable and collapses within fractions of a second when produced in a lab), which are very unlikely to exist anywhere in nature.

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Originally posted by Jack Simth:

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Originally posted by Imperator Fyron:
Complex alien organisms that do not rely on oxygen could not rely on a single gas; they would have to use several things to fulfill all of the roles of oxygen.

And the problem with relying on multiple things is what, exactly?

The more things that have to be relied on when life is evolving, the less likely it is that it will evolve in that manner. I did not say it was impossible for such a thing to happen, just less likely.

Henk:

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If not oxygen but another molecule, that can generate sufficient amounts of energy in biological processes, was used in evolution, then life would have adapted to this situation, and proteins and other processes would have developed that would exploit this resource, making this molecule look "just perfect". Maybe then we would have laughed at the thought of oxygen-dependent life.

Yes, but what molecule would that be? It is all fine and well to make statements like that, but without any examples, it is meaningless.

DS:

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By the time you eliminate the ones that can only exist in a proton accelerator/ the centre of a star/ supernova/ black hole etc, you find that there are only about 100 or so elements actually available to Mother Nature for making life. We know the properties of all of those elements, and so we can make some pretty good assumptions about what aliens will be made of.

Exactly.

Oleg:

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It is mostly CO2 with some water vapor. N2 is not important for us to breath, Appolo astronauts used pure oxygen. Proved to be very dangerous though - Appolo 1.

I forget exactly how it benefits us, but nitrogen is used by some bacteria that live in our lungs to produce some proteins or somesuch that are vital to us. These substances can of course be ingested artificially.

Suicide Junkie · #37 July 16th, 2003, 10:36 PM

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Originally posted by Loser:

quote:
Originally posted by Taera:
i know very little of the later planets in the solar system

The outer planets are just too cold. No terraforming options out there.

Giant orbiting mirrors!
Lots of fusion reactors running off the H2 from the gas giants!
Move the planet!

Loser · #38 July 16th, 2003, 10:57 PM

Quote:

Originally posted by Suicide Junkie:

quote:
Originally posted by Loser:

quote:
Originally posted by Taera:
i know very little of the later planets in the solar system

The outer planets are just too cold. No terraforming options out there.
Giant orbiting mirrors!
Lots of fusion reactors running off the H2 from the gas giants!
Move the planet!

Better off terraforming Luna. Mars is still the easiest.

Erax · #39 July 16th, 2003, 11:55 PM

Nitrogen as it exists in our atmosphere - N2 - is too stable to be usable by most life forms, except a few bacteria. Other life forms require nitrogen in other forms - as ammonia, NH4+, nitrates or amines. The process by which N2 is converted to ammonia is called fixation.

Nitrogen is present in all amino acids, which are called that because they are both amines and organic acids. Life as we know it would be impossible without nitrogen, because there would be no amino acids and therefore no proteins.

Follow this link for an extensive treaty on the nitrogen cycle and how it is important to life on Earth.

geoschmo · #40 July 17th, 2003, 01:25 AM

[quote]Originally posted by dogscoff:

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By the time you eliminate the ones that can only exist in a proton accelerator/ the centre of a star/ supernova/ black hole etc, you find that there are only about 100 or so elements actually available to Mother Nature for making life. We know the properties of all of those elements, and so we can make some pretty good assumptions about what aliens will be made of.

Well dang. That makes a lot of sense teh way you put it there, but it's kind of depressing. It makes it seem like we are closer to the end of knowing pretty much everything then to the begining.