| I like to daydream about space colonization too. Each world has its own challenges: * Mercury Advantages: There's rocks we can mine and water, no need for a heating system in the underground cities, strong-enough gravity and magnetic field. Inconvenients: Spending over 6 years in a small spaceship is quite insane, the water may be irradiated, underground cities are extremely expensive to build compared with surface cities, there's only room for two megacities at the poles unless we do a Death Star kind of urbanization (then there may not be enough water). * Venus Advantages: less than a year of travel away, good gravity and a big atmosphere that compensates the lack of magnetic field, rocks we can mine, the high pressure and heat are manageable with our technology (the Russian probes had insufficient protections against heat), no need for underground cities. Inconvenients: No water (there's H and O in the sulfuric acid but the collect and transform process may be expensive), there may be no nitrogen sources to cheaply make our air, the cooling system is a critical infrastructure. * The deep sea of Earth Advantages: only a few hours of travel away, warm (5 to 0°C), cheap geothermic energy, extremely resilient to asteroid impacts, more than abundant water and rocks we can mine, no need to build underground cities. Inconvenients: much worse pressure than on Venus, total darkness and the layer of sand/dust make it hard to find potential mines. * Moon Advantages: only a few days of travel away, rocks we can mine, gravity may be sufficient. Inconvenients: water is expensive to extract from the dust layer, requires underground cities (or does the Earth act as a shield?), there may be no nitrogen sources to cheaply make our air. * Mars Advantages: less than a year of travel away, water and rocks we can mine, no extreme temperatures thanks to the atmosphere. Inconvenients: sand tempests, no magnetic field so underground cities may be necessary, the heating system is a critical infrastructure as with all worlds beyond the Earth (but we know how to heat stuff), there may be no nitrogen sources to cheaply make our air. * Callisto Advantages: the only Jovian moon we can colonize (it's away from the radiations of Jupiter), water and rocks we can mine, would enable the robotic mining of all Jovian moons. Inconvenients: several years of travel away (5?), requires underground cities, extremely cold. * Titan Advantages: abundant water, nitrogen and hydrocarbons, a thick atmosphere, no need for underground cities, may host life. Inconvenients: at least 7 years of travel away, there may not be rocks we can mine on its surface (which would make it impossible to build cities), extremely cold. Those are the low-hanging fruits of our solar system, and they're all hanging higher than we would have liked. |
Pity the atmosphere is so inhospitable, the surface so bland, and the utter lack of lifeforms. But a little work, and it will probably resemble Earth.
As for Mars, Mercury, and the Moon...Mercury is a surprising read. Mars would need nuclear reactors, I agree, or some other process for creating energy (anything in the soil that could react chemically with something else?). And the Moon...hmm. There's just a lack of data here, for all of them.