I have a SF short-story idea, but I'm having a problem fleshing it out (terraforming question here)

[NickB79]

I have an idea for a short story in my head that is inspired by some of Stephen Baxter's writings, in that it takes place over vast stretches of time into the distant future. A central aspect of it would involve planetary terraforming within a huge number of star systems spread across our galaxy.

The problem that keeps bugging me is that all the ideas I've seen kicked around about how to terraform dead or near-dead worlds only scratch the surface, literally. Take Mars for example. It has no active, molten core, which means no plate tectonics, no volcanism, and a very weak electromagnetic field. If we were to terraform it with our current ideas (thaw the CO2 polar caps, melt the subsoil ice, bulk up the atmosphere, etc), it may be liveable for tens of thousands of years, but would require constant human intervention to make up for the lack of working hydrological and geological cycles or risk falling back to a nearly dead world. To create a terraformed world that will maintain a rich diversity of life for billions of years requires a molten core.

So, can someone suggest a plausible idea on how to re-liquify a planetary core without destroying the planet itself? Antimatter injections of some sort? Massive artificial gravity systems that flex the planet's core to generate internal heat like we see on Io or Europa? Anything?

Thanks!

[Pab Sungenis]

1. If we can spare the energy needed to terraform a planet

then we have the energy to maintain that terraforming without resorting to drastic measures to make it autonomous.

The question is not whether we want to keep intervening to keep a planet habitable over a longer period than 10,000 years, but whether the planet can support itself well enough to make it worth maintaining the terraforming.

And would we even want to terraform a planet that would maintain itself as a biosphere? The reason we would terraform a planet is so that we could live there, not so it would become an evolving biosphere that could do without us.

If it's giving you a problem just assume that the problem will be solved by the time your story takes place. Don't let things like that get in the way of telling your story.

[krispos42]

2. I can't think of an easy way to jump-start the core.

I suppose you could generate some sort of massive electromagnetic field and apply it to the core, making it spin and letting the friction build up heat, but that's one hell of a project.


However, as long as humans had the technology, we could resupply the atmosphere of, say, Mars with a daily bombardment of huge chunks of ice from Earth.

Assuming we build one or more space elevators, then we could regularly pump up vast quantities of water to the edge of the tether and let them loose at the precise time to put them on an orbit for Mars. Slamming a few thousands tons of mineral-and-organism-rich seawater into Mars every day could really help keep the atmosphere thick and would provide needed moisture.

Just, yanno... aim really carefully.

[getting old in mke]

3. Blog entry on terraforming Mars that brings up the magnetic problems

of a solid core:

http://www.philforhumanity.com/Terraforming_Mars.html

[wyldwolf]

4. Protomatter. It worked for Dr. David Marcus... sort of.

[phantom power]

5. If you have that kind of energy available, and you want time...

Then I would drag planets of the right size and core activity into the habitable zone around very long-lived red dwarf stars, which can burn stably for hundreds of billions of years. Also, red dwarfs may not require a planet to have a shielding magnetic field, as they aren't as active as a star like our sun.

Life on earth will get less than 10 billion years before the sun starts to move off the main sequence. A planet orbiting a red dwarf could possibly get a hundred times that.

[quakerboy]

6. How quick do you want it terraformed?

Hit it with another planet, thus remaking the whole thing and giving you a nicely sized moon for tides, then wait for it to cool and settle enough to use. If its good enough for earth, it oughta be good enough for earth2.0, right?