Okay, the real intelligent people will pipe up on this one…
I’ve read the threads about sending plants to the moon to generate O2 and start a colony. Lack of an atmosphere or the gravitational pull to keep an atmosphere seems to be the main problem…
What about the same proposition to:
A) Mars
B) Europa
C) The International Space Station
Mars: atmosphere is too thin.
Europa: atmosphere is too cold.
The ISS: not enough area. Plant to animal ratio is pretty high.
I’ve always thought that the easiest way to get more livable space in the short term was to build colonies in orbit. Put a mass driver on the moon to shoot raw materials into the Lagrange points at L4 and L5, then assemble colonies. The colonies are so big they will house tens of thousands of people, their own agriculture and atmosphere production, etc. They can then be used to support orbital operations, become factories for the manufacture of satellites, maintain solar power satellites, etc.
There’s no reason why you couldn’t have millions of people living in orbit around the Earth.
To use plants to produce oxygen, you need carbon dioxide. On the ISS, you’ve got plenty of CO[sub]2[/sub] being produced by the astronauts, but there’s not enough room for the plants. All we know about Europa is that it has water (which is nice), but we don’t know much about what other substances are present, so it might or might not work. On Mars, though, the atmosphere, such as it is, is almost pure carbon dioxide, and there’s a lot more locked up in the polar caps, if you can evaporate it. Given enough time (and it would take a very long time, indeed), we might actually be able to terraform Mars this way. Of course, it wouldn’t be easy: For starters, you’d need a very durable plant to be able to survive the Martian environment. Some lichens could probably fit the bill, but I don’t think that anyone’s ever done studies on lichens’ tolerance to low atmospheric pressures.
What about those mosses in Antartica? They have to endure below freezing temperatures and survive half the year with no sun and the other half with 24 hour sun. If they could withstand the low air pressures they’d be your best bet. Send a whole heap of them to the edges of the ice caps.
But terra-forming would obviously take a long time, the better solution is to construct large pressurized greenhouses where you can grow your food and produce oxygen. While the terra-forming outside is taking place.
Another thing we could do is divert frozen asteroids or comets towards Mars, or Venus. Just like they did in 2001: A Space Odessy.
What about Venus? All you’d have to do there is get rid of the acid rain and decrease the air pressure. Send plants and wait along time.
PerfectDark
Could lichens line the interior of the ISS?
It seems a relatively inexepensive mission to seed Mars with lichen, if the ship crashes… mission accomplished.
Or perhaps the lander could be a large balloon filled with the necessary ingredients to promote the growth of our space-moss, water and lotsa wet and spongy lichen.
<Splat> instant atmosphere 
The ability for a body to keep an atmosphere is exactly the same as its mass. The Earth can keep an atmosphere (maybe it’s a little polluted, but that’s not the issue). The Earth’s moon cannot. So Europa and the ISS are definitely out.
Mars, quite contrary to “Total Recall” cannot keep a dense, Earth-like atmosphere, either. At least not indefinitely. It is possible for Mars to temporarily keep a useful atmosphere, so long as it is being continuously replenished. That’s what I remember from my NASA days.
How 'bout this:
We create an ice meteor filled with goodies like spores, amoebas, and other simple life forms. Make it big, so it doesn’t burn up going through whatever the planet has as an atmosphere. Hit some nice low spots, like valleys, near the equator or known hotspots. Then, if we’re lucky, we’ll create a small ocean (Okay, a lake) with a premade primordial soup, complete with pond scum! Do it enough, and on enough planets, and we might seed some really interesting life. All it would take is a few million years to see a biodiversity explosion. And even before then, the organisms we sent up would be cranking out an atmosphere, setting up a greenhouse effect, and making Arrak…uh…Mars bloom!
(This is a nutshell account of the ‘seeding’ hypothesis, one of the more…interesting hypotheses about how life got started here. Just replace ‘We’ with ‘Some aliens’ and ‘Mars’ with ‘Earth’. Occam’s Razor tears right through it as a hypothesis for how life began here, but we might take a hint from it and use it as a relatively low-cost, low-maintnence way of seeding life on various rocky planets. Advantage: You don’t have to build a spacecraft, just toss an ice meteor with the right chemicals on it in the right direction. Unmanned, unfueled, unguided. Disadvantages: It’s like throwing seeds to the four winds, if done on a large scale with no followup missions. And even if it does take hold on a planet (hopefully Mars) it could be a very long time before anything real comes of it. My take on it: Not viable for seeding Mars, but possibly a low-cost/high-return plan for seeding numerous, more distant, worlds.)
Wouldn’t the microbes and plant life replenish the atomosphere if they thrived on the planet?
The bestt they could do is to put a terrarium-like bubble in the plans so they’re not constantly using new O2. Mars has too salty soil and anything organic that is exposed to martian elements is oxidized (it get’s trashed) so terraforming is WAY off in the future.
Yep. And that’s one of the things that NASA’s Chris McKay and company are hoping. But the underlying problem is that without sufficient gravity, as on Mars, most of an Earth-density atmosphere just bleeds into space. What’s left is not enough for Earth animals to breath. If the lost gases are replaced quickly enough then a more dense atmosphere can be sustained. The existing life on Mars, if any, make do with an extremely thin atmosphere.
One of the mysteries of Mars is what happened to its atmosphere. It should have been able to hold on to much more CO[sub]2[/sub] than it currently has.
I’m not sure if anyone has any good theories about what happened to it. Anyone know?
It doesn’t matter if a body is too small to hold an atmosphere permanently. If you could put an earth-type atmosphere on the moon, it would stay largely the same for hundreds of thousands or millions of years, and if we have the technology to put it there in the first place we’ll certainly have the technology to replenish any losses. It’s only over huge timespans that a weak gravity will have an effect (unless we’re talking about something really small like Ceres or one of the smaller moons of Jupiter).
If the body is too small it won’t have a strong enough gravitational force to stop the Solar Wind’s blowing the atmosphere away. I think it would also help if the body had a magnetic field to pretect from the Solar Winds.
Unfortunetly the moon doesn’t have enough mass and I am not sure but think it has a very weak magnetic field or none (I can’t really remember). Though Mars does have more mass than the moon it still doesn’t have enough to hold onto an Earth sized atmosphere, I heard it doesn’t have any magnetic field but don’t quote me.
PerfectDark
Uh, no. Atmosphere on the moon would dissipate almost immediately. I don’t remember the specific figures, but we’re talking weeks, not thousands of years. Mars is better, but again I can’t remember exactly. A permanant Mars atmosphere is at best something worse than Mount Everest on a bad day.
What about what clayton said?
I remember seeing paintings in elementary school of the future moonbase (this was during the Apollo missions) and in the background were huge plexiglass dome greenhouses. Wouldn’t this work on the moon?
And as for mars, some plants are moderately salt-tolerant. If we could isolate the genes responsible, we might be able to enhance that trait and maybe genetically modify them for tolerance to cold too.
Jack@ss, Clayton, and co.,
It’s been awhile since I had anything to do with folks planning moon and mars colonies, so I can’t remember all the details, but…
A couple big problems with the moon, along with its lack of atmosphere, water and low cost Burger Kings, are its temperature extremes and the solar radiation. As I recall the radiation alone is enough to drive habitations a couple feet underground. So now we’re talking cave. Sealing off a cave is no problem, at least on Earth, and it’s probably relatively easy on the moon, after all, compared to Earth there’s practically no erosion, quakes, etc.
The major need for sunlight would be for edible or oxygen producing plants, not for humans. But the direct sunlight would be far too strong, direct, and long-lasting, so it would need to be both filtered and capable of being shut off entirely. So I suppose they might be underground or in very low greenhouses.
By the way Sam Stone, I notice that low temperatures on the moon are cold enough to liquify and freeze oxygen. While the hot side would boil like crazy. I’d like to see a simulation of the planetary zone where the rising sun hits the liquid oxygen! Explosions, perhaps. Hmm, maybe I’ll borrow some dry ice from the ice cream wagon…
Hello, I have been looking at the conversations ensuing from the above topic. I did a sememster at the Biosphere in Oracle Arizona, and from what I can see the probability of a biosphere on a Planet is low, as of now. And the Idea of “Terra-Forming” I think is wonderful for a good Arther C. Clark Book or the second Aliens movie, but playing God or mother nature is inherently bad. NASA may like the idea, but I too beleive we are way off from the physical manifestation of a colony on another planet. [orbital colonies maybe] I would like to see us clean up the hand we have been dealt before abandoning all hope and polluting another planet.
Who said anything about abandoning Earth? We have more than enough people to populate two or three planets rather densely, and moving mass into space is expensive, so we won’t be abandoning Earth for a long time to come.
Polluting another planet? We are not proposing a rocket full of smoke belching factories manned by baby seal killing employees, tossing garbage out the windows of their Cadillac Coup de Carcinogens whilst driving to work through the remnants of a bulldozed forest.
We speak of peaceful lichens and friendly microbes, living in harmony on an otherwise cold and barren planet. How could “God” frown upon this act?