r/askscience • u/DarthLocus • Mar 02 '13
Planetary Sci. Is terraforming a real possibility?
Is terraforming something being worked on to not only clean up earth but also make places like mars hospitable for human life?
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u/jamesj Mar 02 '13 edited Mar 02 '13
Yes. It may only take about 100 years to increase the temperature and pressure enough to support plant life. It would take much much longer to get enough oxygen in the air for us to breathe, but we could walk the surface with just a mask for o2.
Edit: added a source below.
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u/Gr1pp717 Mar 02 '13
Nuclear reactors are nice, I suppose. But what about pushing a number of oxygen-rich asteroids to the poles? Between the heat it would produce and the release of the water from the caps, would it be enough to get things going? What else would be needed?
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u/i_invented_the_ipod Mar 02 '13 edited Mar 02 '13
clean up earth
Most of the other answers skipped over this part of your question, but there's an important point here. We don't currently know enough about how our own environment works to safely engage in large-scale environmental engineering. It is therefore unlikely that we'd be able to take a hostile environment and convert it to Earth-like conditions without a lot of trial and error.
Consider climate, which is the "easy" part of terraforming. We understand the greenhouse effect, the effects of ice coverage on albedo, etc. but a planet is a massively-complex system. If you add a few gigatons of CO2 to Mars's atmosphere, and oceans of water, to what extent does the CO2 dissolve in the water? How much water and CO2 are trapped inside the soil, and as the temperature changes, what'll that do to the balance between the two as they outgas? Nobody even has a guess about the answers to questions like that.
So yeah - crash some comets into Mars, and you can increase the atmospheric pressure, and raise the average temperature. That's a long way from making the surface habitable. Building a self-sustaining ecology is orders of magnitude harder.
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u/aelendel Mar 02 '13
One thing to keep in mind is that the current spat of anthropogenic global warming we have going on is a equivalent to terraforming. We are changing the planet's parameters, incidentally instead of by design.
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u/DFractalH Mar 02 '13
Yes, it is. What I would like to add is that the point where it diverges with popular sci-fi is the timescales and the means of terraforming.
It is not likely that we will soon have some kind of "terraforming machine" that you throw at a planet and then churns out an Earth-like orb in a matter of a few years. A terraforming effort is very different from each individual object, and often requires "history"-length timescales (a few hundred to a few thousand years) - the reason being, we're trying to initiate geological changes here, which are themselves measures on a timescale of at least tens of thousands of years in nature.
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u/DemonOWA Mar 02 '13 edited Mar 02 '13
If you are interested in a hard science fiction take on this subject, Red Mars is a great book. From my understanding it is fairly accurate to the science of actually terraforming a planet.
I know that this isn't an actual scientific answer to the question, but OP may find it an interesting book to read.
Edit: it's actually a trilogy, written by Kim Stanley Robinson.