Leaving the Earth behind us
December 10, 2006 2:11 AM   Subscribe

Assume space travel is currently safe, as fast as possible and comparatively (compared to now) inexpensive. How feasible would it be to start colonizing a planet in a new solar system in a self-sustaining way knowing what we know now? Is this being thought about?

Some possible considerations are as follows. Is there a known candidate planet? Is there a readily available energy source to sustain life? Where would water come from? What food sources could be used? How many different people do you need to start populating a new area?
posted by vizsla to Science & Nature (15 answers total) 3 users marked this as a favorite
I'm pretty sure I've read that there is no known candidate planet, though I can't find where I read that. I do know that it's only in the last few years that scientists have even been able to directly detect extrasolar planets -- some information here. From that press release it seems like it would be surprising if we yet had the technology to find out much about far-away planets beyond their mass and orbit.

While googling that up I came across this nasa program, which is relevant to your second question ("scheduled to launch within the next decade").
posted by advil at 2:49 AM on December 10, 2006

IANCarl Sagan, but I had a few classes this semester that dealt with this. The following is all hypothetical.

Depends on what "as fast as possible" means. Even if we could travel at the speed of light, it'd still take hundreds or thousands of years to reach another planet outside of our solar system, rendering the question moot. However, if you're talking Star Trek-ish technology, where travel to certain coordinates can be accomplished in an instant, it would certainly be a bit easier, but we have no idea if this is even possible.

AFAIK, we haven't found an Earth-like planet in another solar system as of yet, but most space junkies agree that Earth can't be the only planet that gives rise to life. We just need to find a planet a similar distance from a mid-sized main sequence star, with a similar atmospheric makeup (i.e. we can breathe it).

We'd probably have to send a few groups of specialists to this new planet, first. Architects, construction workers, scientists, farmers, etc. These people would have to set up the things that would make living close to "normal." Water purification plants would need to be set up, shelters would need to be built, electricity would need to be generated. I assume that renewable energy such as hydroelectricity could be used at first, while the population was small, which would cut down on pollution.

The scientists would have to figure out what sorts of plants and animals would be edible, of course. Just because cows evolved to be yummy here doesn't mean that they didn't evolve on this hypothetical new planet to be made entirely out of botulism and e. coli. They'd also have to figure out if WE would be harmful to life on the new planet. Our bacteria and virii that live on and around us with no problem could hurt or kill members of this unknown planet. Farmers would then have to domesticate and raise these edible animals, and then learn how the native plants are best raised. Architects and construction workers would have to build shelters.

It would certainly take a heck of a long time to begin populating a new planet. A hundred years, maybe. You'd probably need a few hundred people at minimum, if not a few thousand. Most, if not all of them would have to be specialists: engineers, scientists, architects, doctors, nurses, military (for protecwhatever.

This is just my opinion from what I know. I get the impression from a lot of different sources that it'd take a looooong time.
posted by Verdandi at 2:52 AM on December 10, 2006

The problem with your question is "self-sustaining". We do not know enough about ecology now to set up a self-sustaining one that humans can live in. And we do not really know yet how many, and what kinds, of human specialists are needed for a self-sustaining high-tech culture.

Getting there, as horrible as that problem is, is the easy part. (I wrote about some of these issues here.)
posted by Steven C. Den Beste at 3:10 AM on December 10, 2006

Does it even look feasible that we will ever be able to travel faster then the speed of light?

Also what about terraforming a Planet like Mars? Is there any way to warm mars up?
posted by Dreamghost at 3:57 AM on December 10, 2006

we will probably never be able to travel faster than light, if Hawking is right. We would need "generation ships" to cross the void, and I'm not so sure that there are many people willing to get on this ship, if only their grand-children will be able to settle on another planet. It would really mean a huge sacrifice, and I'm not so sure how the first ship-born generation would feel about beeing stuck a flying prison in the midst of nothing, without the chance of going to another place in their lifetime.

Steven C. Den Beste: good article. I've wondered about welding in space before. Does anybody know if there is such a technique?
But I do tink you overestimate the population regulation problem.
posted by kolophon at 6:04 AM on December 10, 2006

I think it is possible, given the get-there-ASAP variable is handled efficiently -- considering we've already taken it upon ourselves to colonize Earth's orbit to a degree.

What would be even better is a more efficient gravity-escape method, whereby taking off from Earth/Mars/whathaveyou would be loads easier.
posted by vanoakenfold at 6:29 AM on December 10, 2006

FWIW, the jury is kind of still out on whether we have a self-sustaining population on this planet.

Sure, it breeds and grows, but that's is not a definition of perpetual success. It's only "successful" if you limit the time span under consideration. And as dinosaurs demonstrated, sometimes the rules change pretty fast and invalidate today's successful strategies with species-numbing results.

Notwithstanding the rather gargantuan technical obstacles of finding a suitable destination, planning/staging/executing transport, temporal limitations (one human life span versus the transport interval), inadequate understanding of what is needed at the destination, etc., just imagine the difficultly of managing a confined population in enforced stability of a few hundred / thousand years on the trip out. We can't even manage to resolve a 5000 year old argument over who owns Palestine (sic).

At the current state of our understanding of physics, I suspect that the combination of technical and social obstacles pretty much rules out extra-solar planetary colonization due mostly to time and resource constraints.

Besides, why? If we could possibly manage the things needed for such an adventure, why would we not employ them here? What the hell's wrong with this planet?

"Space colonization" seems a euphemism for finding another place to fuck up, so we can start a series, it seems to me. It's a nice thought experiment, and wonderful escapism fodder for fiction creators, but how about asking a question like:

"How do we manage a planet with too many people whose systems are becoming unbalanced?" Successfully resolving this conundrum might be the best preparation of eventual space colonization AND simultaneously eliminate the need to pursue it.
posted by FauxScot at 6:45 AM on December 10, 2006


One more thing... "How many different people do you need to start populating a new area?" is a huge question.

More than two.

The same question is one posed in a selective breeding project I was involved in for a long time, involving integrating pathogen resistance into a non-resistant species via classical breeding techniques, using a small population of 'sources of resistance' parents and a large population of non-resistant parents.

How many non-resistant parents would be needed to assure sufficient genetic diversity to improve survival in natural settings after release? The original population of non-resistant parents was estimated to be about a billion members, and the geographic distribution of the species a few million square miles.

The relevance to your sub-question is that this question (25 years old) has been the subject of scores of PhD's in innumerable meetings. No resolution yet. None in sight.

What are you going to encounter out on Planet X? What kind of genetic diversity do you need? In human populations, sickle-cell anemia (a seeming negative) is an evolutionary byproduct of a successful adaptation to an environmental stressor (a pathogen). What do you take with you? What works in space on this planet now is no predictor of what will work 'out there, then'. Do you make sure you take some 'defective' humans? Do you just take a pile of DNA samples or recepies for genes and the technology to implement instant evolution?

It's not a stupid question, but its simplicity sits atop some enormous implications. This one of 'genetic diversity' is a good example of how the devil is in the details... and there are details without end.
posted by FauxScot at 7:07 AM on December 10, 2006

Verdandi writes "Even if we could travel at the speed of light, it'd still take hundreds or thousands of years to reach another planet outside of our solar system, rendering the question moot. "

There are hundreds of systems within a 100 light years. Heck there are 63 with 5 parsecs(16 light years). The nearest are only 4 1/2 light years away. Depending on the nature of your C drive trip duration would be well within a generation, even for a return trip. For people taking on 40 year mortgages a 15 year time dilated return trip should be no problem.
posted by Mitheral at 8:12 AM on December 10, 2006

The scientists would have to figure out what sorts of plants and animals would be edible

Too much of a crap shoot, better to bring samples / DNA of all our Earth stuff with us.

Our bacteria and virii that live on and around us with no problem could hurt or kill members of this unknown planet

Well boo hoo hoo. So what?
posted by Meatbomb at 8:13 AM on December 10, 2006

I don't know if you'll find this useful: Speaking as an amateur, I bet that most of the serious thought depends of a cushion of time before we begin to send something.

That is to say, we expect the technology of travel to grow pretty rapidly, so even if we can send something this century that goes at 1/100th the speed of light, we'd do much better to wait 500 years and send something that can go 2/3rds the speed of light.

So, given that we have plenty of time before we expect to send something, I bet that no one expects current ideas to be worth a lot when that thousand years is up.
posted by cmiller at 8:19 AM on December 10, 2006

posted by cmiller at 8:19 AM on December 10, 2006

You'll find a lot of info and links within the wikipedia category on Space colonisation.

And what cmiller said. By the time we have developed technology to get us comfortably to a suitable planet, other technologies (relating to biology, chemistry, ecology and so on) will be so far in advance of present day that its futile asking specific questions now.

If we are to start answering these questions, it will likely be from establishing colonies on Mars, Titan and in orbit. I would expect (IANAScientist) solar colonisation to be fairly well developed before we get anywhere near extra-solar colonisation.
posted by MetaMonkey at 11:35 AM on December 10, 2006

There is always the possibility of terraforming Mars.
posted by ASM at 2:48 PM on December 10, 2006

Honestly, by the time we have the kind of technology available to us where space travel is cheap, we won't really need to go anywhere far off. Anybody who can hop a few star systems will have developed the kind of technologies where fresh water could be manufactured from rocks.
posted by adipocere at 3:56 PM on December 10, 2006

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