Ah, Mars terraforming. One of my favourite topics of interest...
Mars is probably the closest thing you could compare to an "easily terraformable planet". In terms of ease of terraforming, Mars far surpasses any other body in our system (Venus is for those who fly XR2s to work, the moons and mercury are either too small or too dead or too important to terraform).
We can do away with such nonsense as crashing Phobos or drilling holes, simply, because we do not need to. The first and foremost issue is heating the planet to release CO2 and water vapour, to form a primitive atmosphere. This can be done in three ways:
- Dust the icecaps with dark material, to promote sublimation, increase of atmospheric CO2 and water vapour, and increasing planetary temperature.
- Manufacture super-greenhouse gases such as CFCs or PFCs using local materials.
- Aim a soletta mirror or statite (i.e. a non-orbital solar sail that balances the pull of gravity with solar radiation pressure) at the polar caps, promoting sublimation of CO2 and water vapour, with the same objective as concept #1.
To make Mars habitable, however, we need a breathable atmosphere, containing oxygen, as well as a buffer gas- i.e, some inert gas. Nitrogen is the preferred choice, especially because it is required by some plants, and is what we have lived with on Earth for billions of years. Other suitably inert gases, such as Argon, are probably not as abundant as nitrogen either.
Something that has plagued me personally (and to an extent scientists proposing terraforming concepts) is the apparent lack of nitrogen in the Martian crust, which would lead to a requirement to import nitrogen from elsewhere in the solar system (such as Titan or comets), and this would be extremely costly. However, recently, it has been suggested (or discovered, I'm not really sure :uhh: ) that Mars has relatively sizable amounts of nitrate in the topsoil in certain regions, and this could increase with depth.
Oxygen is the last problem, and obtaining it will probably be pretty difficult- it should be a major chemical component of the crust, but the problem is, it's locked away in oxides. I'm not sure... maybe a potential for oxygen production is splitting water. Photosynthesis works too but it obviously has its disadvantages, not to mention the fact that many plants need oxygen to function in the first place.
Keeping carbon dioxide below a certain level is also important.
It is worth noting that while Earth's atmosphere is roughly 9.81 tons per every square meter, because Mars has a lower gravity, it needs more mass per area for a given pressure- in this case, around 27 tons/m^2 for a roughly 1 bar atmosphere.
The amount of water is also an interesting issue. Mars should have a good deal of water stored away in it's vast amounts of permafrost, and it's topography means that water will tend to collect in the numerous depressions across the Martian landscape- craters. Mars hasn't seen the water erosion that Earth has, so it still has this interesting depression distribution... it is important because it doesn't mean all the water is dumped in the ocean, a lot of it can be dumped "inland" (in the highlands) where it might be needed.
Of course imports are an option of more water is required, from bodies such as asteroids or comets, but this will also be problematic and expensive... I also think, though, that gradual distribution of small hydrated fragments (i.e. icy gravel) would make a better delivery system for water than large, monolithic impacts (which could be pretty damaging).
I believe one of the fancy atmosphere plot calculators someone posted here once showed Mars as being able to retain a nitrogen and oxygen atmosphere (good) but not water vapour (bad). But humans are not stupid, and we can be proactive about it, especially over such long timescales... setting up atmospheric UV shields (such as an ozone layer, if possible) or even space based shields might prove effective, and magnetic shielding of the atmosphere (perhaps by a coil at the L1 point) would help to reduce losses. But that is most definitely a solution for further in the future; we will certainly have a good deal of time, before Mars starts to lose atmosphere and water to space.
Mars has 144 798 500 km^2 of surface area. If we assume 40% of that is water, and 25% of the remaining land area is totally uninhabitable (polar desert or highlands- Tharsis is a real bother, even with a thick atmosphere it's dry, cold and thin aired, like a third polar cap at the equator), that is 65 159 325 km^2.
Which is almost four times the area of Russia, more than seven times the USA, and 8.5 times Australia. If the entire area had the population of the US, a developed country with plenty of industry, but large amounts of farmland and set-aside natural land, Mars could house 2.19 billion people. Mind you a lot of Mars will probably have Canadian climate, so it could be lower... then again there are probably going to be quite large settlements on the equator.
Should we terraform Mars? I for one, are very tired of those who proclaim we could never do such a thing, that we're "too small", and that's rubbish. We, like any other organism, can change our environment- and we have been changing our planetary environment, virtually from the agricultural revolution. This is on a different scale, of course, but dismissing it outright strikes me as downright silly.
I am also tired of those who abhor the concept of terraforming Mars, because we shouldn't mess up it's "natural beauty", or that we have some sort of moral obligation to not change the planetary environment wholesale.
Now, to be honest, I love Mars. It's landscapes, it's climate, it's geology, geography, fascinate me intensely. When I look at the rover images, it strikes a chord with me, it's a very interesting landscape, almost like- in Aldrin's description of the Moon- magnificent desolation.
But then I look at the terraforming potential, and I wonder; how much more beautiful are those dunefields or rockfields, than a living world, with water, foliage, wildlife, and human activity layered over it? I know that by terraforming Mars we will remove some of it's grace, and it will be radically changed, but the gain outweighs the loss. And in the end we will never, ever manage to make Mars into another Earth; Mars is Mars, and despite any "terra" "forming" you give her, she'll still be there. It's just like... a planetary makeover.
Of course the real problem is the potential for native life, and that calls into question the environmental damage potentially done by terraforming. We can only seriously regard life as occuring relatively deep within the soil or the crust, but even then, temperature changes, and of course, the presence of introduced bacteria, would most likely spell the end for such organisms, at least in most regions.
Is this an acceptable loss? Is it acceptable if the organism shares a common ancestor with us (which could be quite probable)? Does introduction and cultivation of diverse terrestrial life warrant potential ecocide on the first extraterrestrial organisms discovered?
I don't know. As much as I would like to see cultivation, such a discovery should be a cherished scientific treasure. Is it worth discarding? It is a massive topic of debate, and one that would certainly balloon to planetary proportions if it were discovered on Mars, in light of potential terraforming.
I personally hope that Mars is dead, so that we can claim it for ourselves and our biological kin. And that is slightly mean, it's colonialist, imperialist... maybe I am thinking too green about it, they're just simple bacteria like organisms. :shifty:
We (more or less) have the technology to terraform Mars today, we just don't have the economy or the willpower, or the knowledge. There's so much we don't know about Mars, let alone how it would react to terraforming... I think that before we ever attempt terraforming, Mars would have to be intensely and comprehensively researched.
. So, it may sound a little egocentric, but our well-being is much more important than theirs.
. Do we like it or not such simple organisms are vital parts of ourselfs
