I do not understand the obsession for focusing on colonizing only planets. We won't be viably "in" space until we produce mass quantities of raw materials from The Moon and asteroids. Lifting from Earth is always more expensive in energy. Once we build space stations, why would people who grew up in them want to live "dirtside"? Why would people who grew up on Earth want to live on Mars instead of a nice climate controlled habitat? I'm sure some will, but I bet most won't. Beyond mining and tourism, I doubt Mars will be heavily populated.
To survive long-term without getting massively irradiated you need, at a minimum, metres of rock between you and the sun (and as you say, lifting them from Earth is going to be expensive). Ideally a magnetosphere too. Gravity is also desirable for health reasons and random practicality things (e.g. in zero-g you have to sleep in a draught, as otherwise there's a risk of a dangerous bubble of CO2 forming around your head). And temperature can be a huge problem for spacecraft that aren't attached to a big heat reservoir - scorching in the sun, freezing in the shade.
Maybe ultimately we'll be able to construct nice habitats for orbiting stations, but with current engineering capabilities rocky bodies are the only safe places to stay long-term. I certainly expect we'll get to asteroids eventually. But for now, Mars is closer than the asteroids, closer in delta-V terms than the Moon, and much more promising in terms of having organic-y raw materials available for farming and fuel. It makes sense to go there (or maybe Venus, but aerostats would be a big chunk of new engineering) first.
Colonizing planets and producing space stations would only help enhance the technology, provide refueling and repair places, and much, much more. People will have preferences on where they want to live (dirtside or not) in the same way people have preferences on where they live now. I think it would be safe to assume there would be a little of both (spaceside and dirtside) living out there. (I think that resource-wise, there will be more on planets because of its benefits)
If economic exploitation of Antarctica, which is only a few hours away from "civilization", has water literally everywhere, and where the air is perfectly breathable is currently not viable, I can't imagine what it would take to make Mars, or mining asteroids, viable.
It's also kind of vital for the balance of the planet's ecosystems, as we're slowly finding out. If we melt it to get materials under there, there's a sizable chance of long term regret.
Whereas Mars doesn't have an ecosystem at present and no species to endanger.
I want to make other planets livable so we can stop killing this one so much.
> I want to make other planets livable so we can stop killing this one so much.
What (insufficient thought it might be) political support there is for efforts to stop killing this planet is based largely on the idea that "its the only one we have", so I'm not sure that really works.
I would certainly be in favor of terraforming Mars, and then seeing what could be done.
One might (or might not...) want to wait until we have clear evidence that it is indeed sterile. In either case the first thing to do would be to seed it with engineered robust lichens, or the like, just to get things started.
>it was quite clear before it became law that there was no real commercial interest in mining or oil exploration in Antarctica for the foreseeable future. [1]
Of course, a vein of pure gold would be worth mining, but I think the main reason is the massive overlay of ice makes most of the minerals inaccessible, except at the fringes of the continent.
Isn't the main issue with Mars not it's atmosphere or landscape but rather the fact that it has no magnetic field to speak of? That poses an issue for electronics as well as any living beings that aren't tardigrades.
Edit: the only solution to this that I can think of would be to have any and all housing underground, since I don't think it will be possible to restore Mars' magnetosphere.
A planetary magnetic field acts as a shield for space-based radiation that may otherwise interfere with biological processes. There's some really nasty stuff out there that the earth's field deflects for us : http://en.wikipedia.org/wiki/Earth%27s_magnetic_field#Magnet...
Yes, that's a big issue for living on the surface. On the other hand the atmosphere is a nice trivially accessible source of a number of important chemicals and makes getting from space to the surface much easier.
Regarding food growing, I sort of expect that on either Mars or the Moon you would end up using solar panels to feed grow lights. You lose power via solar cell inefficiency but you make some of that back by shifting the spectrum of the light you emit into the wavelengths plants can absorb most easily. It's a hassle, but potentially less so than all the dangers your plants could be running into above ground.
And I figure the only viable colonization sites on the moon are the north and south poles, where you can get solar power continuously.
"It is shown, that of all bodies in the solar system other than Earth, Mars is unique in that it has the resources required to support a population of sufficient size to create locally a new branch of human civilization."
Except that despite beautiful renderings of cities on the surface of Mars, the radiation would force everyone to live underground. And if we are going to build huge cities under the surface of Mars, we might as well try it here. But no one is doing it,because there is no point.
