Naked Science Forum

Non Life Sciences => Technology => Topic started by: thedoc on 22/10/2015 14:50:02

Title: Is terraforming possible?
Post by: thedoc on 22/10/2015 14:50:02
Stefan Milde  asked the Naked Scientists:
   Good morning Naked Scientists,

Your current series of programmes is very interesting indeed! One thing I was wondering about is the whole idea of "terraforming" that you hear/read about in SciFi movies and books. While the first explorers would certainly need to grow their food in some sort of greenhouse, would we ever be able to create an actual atmosphere on Mars (or elsewhere for that matter)? Apart from the technical challenges, is such a thing physically possible at all?

Thank you!



   
 
What do you think?
Title: Re: Is terraforming possible?
Post by: chiralSPO on 22/10/2015 15:40:40
It's not physically impossible, even if it is technologically impossible.

We know that both climate and atmospheric composition can be manipulated to some extent. One could imagine bringing atmospheric gases to Mars from somewhere else (maybe stealing nitrogen from Titan and water from comets, and using plants or electrolysis to form oxygen (continuously) on the surface of Mars. You would also need to establish a global magnetic field to protect your newly established atmosphere from solar wind.

Baring revolutionary discoveries relating to gravitation, you would be stuck with the low Martian gravity unless you added enough material to increase the mass dramatically.

There is also the problem of sunlight. I am assuming for now that we can't move the planet (though this is theoretically not impossible). A thicker atmosphere will hold in some heat, but it still would not get nearly warm enough to be T-shirt weather anywhere on Mars. Fission or Fusion energy sources could be used to heat the planet (though I wouldn't want to pay the bill!) One could also imagine using enormous mirrors in space to provide additional sunlight during the day (it might look like another sun, or a very, very bright moon).

Other than the enormous amounts of matter and energy involved, you also have to worry about how long things will take. You can't just flip a switch and change the temperature on a planet. Everything must adjust to a new equilibrium, and such dramatic changes could involve thousands of years of hurricanes (if you're impatient) or millions of years less significant storms...

Establishing an Earth-like biosphere is also potentially feasible, but again, could take eons.