12-17-02, 10:55 PM
I am currently trying to figure out how one would begin to introduce life to a recently terraformed planet. If that isn't enough it would have to be done using the bare minimum number of organisms.
You cant just randomly seed the planet as some plant species would live and some would die. This would cause in a planet lacking a previously established ecology and unbalanced ecosystem. It might fall into a monoculture and become unworkable for decades if not longer. A good example of this is after the asteroid that killed the dinosaurs hit the fossil record shows the core of North America was inhabited by one type of fern for over 100 years. No other plantlife could penetrate its dense foliage.
How would you set up a complete ecology and keep it stable? What is the bare minimum number of species needed to keep a planet's ecosystem stable? How long would each step take?
I appreciate anything from the uninformed guess up to divine inspiration. Thx.
Martyn Fogg is considered one of the top experts on terraforming. There's some of his stuff and others here.
I think you've hit on why we won't be terraforming in the near future...getting the process started is a lot easier than guaranteeing it'll be stable or even go the direction we want.
I get the impression that there's a few steps:
Getting the planet to livable conditions.
Introducing anaerobic life to help increase the changes in the biosphere.
Graduating the anaerobic to aerobic life, much as early earth did.
That is certainly too simplistic, but you can read more in the link.
Once we get Mars livable, then we can think about a greater challenge, Venus.
Somehow building colonies in space doesn't seem that hard. :) Although I suppose it's the same problems of balance, but at least the scale is smaller than Mars.
12-17-02, 11:57 PM
Thanks, its a good start for what I need.
If anyone else has any info, comments, or links dont be shy.
These will throw another wrench into a stable biosphere.
The variation in solar distance during a Mars year - short summers; long, cold winters.
A 100,000 year cycle in those distances - Mars is currently in the middle, meaning that it can get colder than it is now (but also that it can get warmer, briefly).
Another 100,000 year cycle in the axis tilt, from 13 degrees to 42 degrees every 100,000 years, currently at 24.
Would having a thicker atmosphere help even out temperature differences enough, or is Mars looking less and less stable? Certainly the weather is going to be interesting.
Venus may be hell, but at least if we could ever get it habitable, it doesn't have the huge variations that Mars does. It'd be a shame to expend great energy to terraforming a planet that will deep freeze itself for a few 10,000 years. Maybe if we can adjust Mars' orbit...
Would i twork to start forming the biosphere before the terraforming is complete? Say you designed the first generation to give way when you planted the secend as the atmoshere forms and the claimate and such change.
12-18-02, 10:53 PM
It could still form a monoculture resistant to new forms of life. You cant release just a handfull of ill choses life forms and you cant release a large number of finely tuned varieties.
Do the first and you might get a single domanant strain or all of them together would form an equally formidable problem. Do the second and one might go extinct and more might be taken over the edge as well. That would also produce a monoculture.
You might actually have to introduce (I cant believe Im saying this) species specific pathogens and pests to control population density. As the density increases, chances of contamination increases in a direct ratio.
Of course the later colonists would hate you for that.
12-22-02, 09:58 PM
What would happen if you were only halfway through with the terraforming but something happened to stop further human influance. How would a partially constructed ecosystem develop?
I would guess that it depends on what step we've reached. Certainly there will be some points in the process where continued influence is necessary to reach the next stable conditions. There might be some planets that would require constant intervention to prevent sliding backwards into inhabitability. Mars' weak gravity and lack of magnetic field might mean we have to replenish lighter gases frequently and genetically harden organisms to resist mutation from radiation.
On another note, as I mentioned before, are we really sure Mars is that stable in the really long term to even bother terraforming it?
12-22-02, 11:04 PM
For mars I am pretty sure it would lose any atmosphere rather quickly, though that might be 10,000 years. If I was to work on mars I would just cap some of its equatorial craters and pump in a locallized atmosphere. Then I would have to terraform just them.
Anyway, presume the planet in question could retain the atmosphere. Lets say you introduce bacteria, lichen, simple grasses, and perhaps a few invertibrates in the water. There still isnt enough oxygen to support higher life. Human help is then removed completely.