I'm hopelessly uneducated scientifically... My knowledge mostly consists of what I remember from high school and bits and pieces I've picked up over the years. I was wondering how plausible it would be to "seed" a planet with plant life, assuming it had a carbon dioxide-rich atmosphere, liquid water, and a sun at the appropriate distance? And if it would be possible, how long would it take to bring the atmosphere up to breathable levels of oxygen?
Posted by dpatridge (Member # 2208) on :
i think that the general concensus is that it IS possible, but with limitations and complexities.
for soft sf, just do it, and most people will accept it at face.
for hard sf, you have to provide reasoning, and make it plausible. i would suggest you look at the following threads which address, the first on non-martian, which is finding sun-like stars:
There is enough information and direct links on that page to write a thesis. In fact, there are a few thesis' actually linked to the page.
Look under terraforming.
Posted by wbriggs (Member # 2267) on :
I studied this q at one point.
Mars's problem: it's not big enough; its atmosphere is too thin. Also, its air doesn't get colder as you go up, so any water vapor is apt to make it up to be dissociated by solar radiation, and hydrogen can escape.
Venus has the same problem with water, and doesn't have any. As a result it has no CO2 cycle, and the CO2 stays in the atmosphere and builds up, and it's hot enough to melt lead.
If you put algae packs on either, it wouldn't help. They'd freeze on one and burn on the other.
If your world still has liquid water, somehow, I think you're set. In a short while you'll have converted methane-ammonia (I think) to oxy-nitro, which will cause the world to freeze. But supposedly Earth did, until CO2 built up enough to melt the oceans and the CO2 cycle started again. Maybe you can do something to keep it from freezing.
Posted by drosdelnoch (Member # 2281) on :
It would be possible but it would take a number of years to make the whole thing work, however whilst doing that I would suggest that you have a space station for the people who were tereforming to live on, same sort of set up with plants to do the oxygen. There are also plants that filter human waste that would recycle the water.
Willow is the main one and then I think some reeds. Its used by a number of freeholders to avoid septic tanks and stuff.
Posted by ArCHeR (Member # 2067) on :
Well, taking the ingredients you've given, it's almost perfect.
Just throw down a lot of plants first and wait for the oxygen levels to almost even out, then send in living things to balance it out so that the plants don't suffocate.
Posted by AeroB1033 (Member # 1956) on :
Thanks for the responses, everyone. Exactly what I was hoping to hear.
Posted by HuntGod (Member # 2259) on :
It would be easier to smack a giant ball of water (i.e. a comet) into the planet.
If the planet already has a workable atmosphere but is simply lacking the elements needed to sustain human life, then careful cultivation of plant life could probably alter it's composition in a millenia give or take 100 years.
The big question is water content on the planet, if there is already plenty of water, then unlocking the oxygen would be easier and could dramatically speed the terraforming.
Posted by JBSkaggs (Member # 2265) on :
Of course if the planet has large amounts of water and if technology is sufficient to over come the energy requirements one could build massive oxygens extractors to break down water into oxygen and hydrogen. For that matter in soft SF you could build some type of flash bomb that could instantly convert trillions of tons of water instantly into its seperate elements. Whether or not the planet could hold onto these gasses before they escape into space is another question.
Posted by HuntGod (Member # 2259) on :
Well if it has large amounts of liquid water, it probably has a moderate atmosphere. The exception being if it is an iceball, but if it's an iceball then it is probably not close enough to the central star/stars to be a good terra forming prospect.
Posted by Netstorm2k (Member # 2279) on :
So you just stick a really, really big rocket on it, shoot it into a closer orbit like an Eight ball toward the corner pocket, and cook that puppy into life!
Entirely possible, uh huh. I saw it happen once.
Posted by HuntGod (Member # 2259) on :
Affixing a rocket to it would be an interesting technical challenge, detonating a series of low yield nukes to modify it's orbit would be more practical.
Posted by Netstorm2k (Member # 2279) on :
