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Past Thinking about Earth- Like Planets and Life
April 29, 2010 9:30 AM   Subscribe

Past Thinking about Earth-Like Planets and Life [pdf], presenting a brief history of thought on finding extraterrestrial life-like phenomena, is the first chapter of James Kasting's new book, How to Find a Habitable Planet. He participated in a discussion on BBC's The Forum.
posted by jjray (27 comments total) 6 users marked this as a favorite

 
Not that I think pursing terraforming technologies is necessarily a great idea, but I would put a small wager on humans being able to make Mars or something smaller inhabitable on the surface without breathing apparatuses long before we can reach an extra-solar planet with a similar atmosphere as Earth.
posted by Burhanistan at 10:20 AM on April 29, 2010


I dread this text coming into the hands of my overly optimistic and fanciful sci-fi lovin' friends and privately speculate that we could get farther towards solving the overpopulation problem by sterilizing people who suggest terraforming as a solution to the overpopulation problem than we could trying for terraforming as a solution to the overpopulation problem.
posted by adipocere at 10:27 AM on April 29, 2010


The sooner we get a portion of humanity off this pale blue dot, the better. It's the solution to the immediate problem of overpopulation, as well as the long-term one of surviving some catastrophe (man-made or otherwise). In the interest of time, I agree that we should focus on colonizing Mars or another body within range of current rocket propulsion. Terraforming may or may not come later but we can certainly go ahead and build enclosed, climate-controlled settlements now. Humankind needs a self-sufficient, growing population off-world. That should be our top priority.

Finding other Earth-like planets is worthwhile too. It's clear we need to research ways to get there as well, because strapping ourselves to giant bombs and waiting for tens of thousands of years of travel time isn't going to cut it. But I'd suggest that this is research best conducted AFTER the more pressing need is dealt with. The same with terraforming and the search for other intelligent life. These are all noble, worthwhile goals... but we could really benefit from some prioritizing! Mars is nearly attainable NOW.
posted by The Winsome Parker Lewis at 10:42 AM on April 29, 2010 [2 favorites]


I don't buy that overpopulation is really going to kill us off, and some people (such as Pearce) are saying that populations will begin to level off and even naturally decline in a few decades. I don't think exploring other planetary options has to be in reaction to the fear of overpopulation, though. It's something interesting to do that seems to be an extension of our basic need to explore and categorize things.
posted by Burhanistan at 10:47 AM on April 29, 2010 [1 favorite]


I'm not so afraid of overpopulation either, at least not for the next few centuries. There are certainly some places in Asia that are beyond their limits, but there are also plenty of wide open spaces left on the planet too. Seems like the real problem is evenly distributing people (fostering a willingness in them to emigrate, and a willingness in governments to let them).

For me, it's a miracle (in the juggalo sense) that humans have survived this long entirely on one planet. Continuing to sit here without expanding to other worlds is just pressing our luck. If astronomers were to discover a massive astroid on a collision course for Earth, today, we would be stuck without a backup plan.

Not to needlessly spread FUD, of course. I realize what the odds are. We're probably safe here for a very long time. Just not forever. In my opinion, Earth will always be the origin of humanity, but shouldn't always be considered our home. We were meant to scatter.
posted by The Winsome Parker Lewis at 11:00 AM on April 29, 2010


The fact that we have relatively stagnated in terms of exploration, and sending humans to new frontiers (in comparison to the 'explosion' of creativity, and ingenuity and investment that put people on the moon) is actually kind of surprising.

However, before we teraform, or resort to mass sterilization, before we go to space more, before we devote more than half of the budget that is supposed to help us "live" in space, send us underwater... It is the best way as a species to prime and prepare, and learn what it takes to actually 'live' in deepspace/outerspace. And it doesn't need the whole side industry, and side needs and massive external budgets of projects creating "chemical rockets to boost humans safely out of our heavy atmosphere"... learn how to 'live' in closed systems almost completely analogous to space (besides hi-rad levels), people work better when projects are limited in scope, one group working on "propulsion" systems (with sending telepresence robots into space), and the "learning to live" done on planet in the oceans... Win win.? non?
posted by infinite intimation at 11:05 AM on April 29, 2010


er sorry.
before we devote more than half of the budget that is supposed to help us...

Before we devote more than half of the "space/exploration" budget...To rockets and propulsion systems that will be obsolete in just a few cycles around the sun...
I agree with you TWPL, in that Mars is attainable, and that humanity, being explorers, need to do what you suggest, in the near-term; with international, and cross cultural co-operation.

I am only suggesting that we don't need only to make the propulsion systems first, we need to know how we will live sustainably, without all of the abundant, and auto-replenishing life form based resources of our planet; why 'risk' the loss of support, and all the 'fear', uncertainty and riskiness of the "getting into orbit" stage with live people, definitely, keep advancing, funding and progressing in terms of propulsion technology, and such, but we need practice, and to experiment with various ideas for ways and means of living "outside" of the comfortable "landmasses, and borders" that we are familiar with... we need practice living in an 'alien', unforgiving, and hostile environment... where the very thing our lungs need to sustain us is simply not available.
If we can't teraform earth deserts, and in fact our deserts are growing, I don't think we are ready to teraform mars. Smaller scale closed systems with limited inputs however, this we are getting better at.
posted by infinite intimation at 11:41 AM on April 29, 2010


I don't agree that it is a good idea to start to colonize Mars even before terraforming it. Mars needs a huge infusion of volatile substances, which could most conveniently be obtained by nudging comets into collision courses with Mars. But it would not be a good idea to actually be on Mars while those collisions were taking place.

I also think that few people would really want the added uncertainty of living underwater, with the threat that someday the airlocks will fail or the dome will crack, as long as there is any possible real estate left on the land. And even when there is no real estate left on land, I think that floating cities on huge boats or rafts would still be more appealing than living underwater. And then when every inch of land is in use, and every inch of ocean is covered with assorted houseboats, we will start to build houses that float in the air, suspended underneath helium balloons. And all of those options are still cheaper than exporting excess population to Mars, which will never be affordable without some huge technical advance in space travel - teleportation devices would be ideal (but I am not expecting them ever to be invented, alas).
posted by grizzled at 11:42 AM on April 29, 2010 [1 favorite]


-when nudging those comets towards mars, I hope they use either one or the other of metric or imperial measures and don't mix them up... it would be a spectacular "ultimate winner" of the 'Darwin award for science' if we 'accidentally' wiped out earth life when we decided we are ready to teraform mars... and miss, hitting us in the process (I don't think it is a bad idea, or know the actual spatial realities here. this just seemed like a good time to mention that [before it is undertaken])

-Agreed, masses of people might not like the idea of living underwater... most people also didn't want to jump on wooden ships and sail to what was as far as the society of the time knew, or believed, the "edge of the world"... some still did anyway.
posted by infinite intimation at 11:52 AM on April 29, 2010


Mars needs a huge infusion of volatile substances, which could most conveniently be obtained by nudging comets into collision courses with Mars.

That's the funniest thing I've read all week. Anyway, there probably exists all kinds of "volatile substances" in Martian substrata.
posted by Burhanistan at 11:56 AM on April 29, 2010


I agree that when nudging comets into a new orbit, it pays to be extra careful. I wouldn't want to give the contract to Dr. Evil.
Even if there are already volatile substances in the Martian substrata, digging them up and utilizing them is not nearly as good an option for terraforming as comet bombardment would be. To really terraform Mars you would want large open bodies of water, and a relatively thick atmosphere, and you are not going to get those things by mining the substrata.
posted by grizzled at 12:51 PM on April 29, 2010


The more I think about it, the more I'm convinced that we will almost certainly never deeply invest in colonizing habitable planets, and that we will never spend effort terraforming.

Habitable planets are not, in the long term, very good places for humanity to live. Climates change, suddenly and with devastating consequences.

Terraforming, assuming it is ever possible, represents an enormous investment of time, energy, and other resources. For the price of terraforming Mars we could riddle the crust with underground, perfectly climate controlled, habitats.

Colonizing habitable planets and Terraforming, like flying cars, food pills and weather control, seems to be one of those foolish and ultimately pointless SF ideas from the 1950's. The only difference is that those two have lived on somehow in the popular imagination.

As for overpopulation, of course colonizing offplanet won't change it in the slightest. I support colonizing outside our atmosphere out of concern for the future of the species, not to relieve overpopulation here on Earth.
posted by sotonohito at 1:10 PM on April 29, 2010


That is a remarkable assertion, sotonohito, that habitable planets are not, in the long term, very good places for humanity to live. You haven't suggested a better place. You did suggest building underground habitats on Earth as a cheaper alternative to colonizing Mars, but such habitats would still be located on (or inside of) a habitable planet. I agree that habitable planets have various troublesome features - ours has periodic earthquakes, tornadoes, volcanoes, etc. - although planets certainly have their advantages as well. You could live on a space station and never have an earthquake or a tornado, but if it develops an air leak you could face a much more serious problem.
It is also true that in the sufficiently long term, the Earth does not remain habitable. In about 3 billion years, the sun will expand into a red giant and the Earth will become much too hot. (It may also become much too hot a lot sooner, due to the greenhouse effect.) I don't know that it is really necessary to plan for 3 billion years in the future. If the human race still exists in the far future, it may have technology so powerful that the whole issue of where to live becomes trivial. Perhaps whole planets and solar systems could be custom designed and built to order. Planets do not have to have earthquakes, you know. Earthquakes require a hot interior, which in turn requires the presence of radioactive isotopes that generate heat. I would rather design a planet with an interior that has no radioactivity and which is both cold and solid, all the way to the center. Or, who knows, perhaps planets will be obsolete, at some future date, and everyone will live inside space stations or space ships. Although I am not generally that optimistic. Given the various crises of the 21st century, the human race is going to have to really get its act together or civilization as we know it is going to go into a steep decline, and the issue of whether we might like to terraform other planets, build habitable space stations, riddle the crust with underground habitats, etc., will become entirely moot.
posted by grizzled at 1:31 PM on April 29, 2010


Ok, it's kind of insane to just say we can go to the comet supermarket and then take those back to the target planet and then laser guide them to crash and make oceans and what not. I'm not saying it's out of the realm of possibilities, and it sure would be cool if we had the means to explore and asses Kuiper Belt objects and then tow them to the site of our choosing. But that capability is probably a long, long way off.

In the meantime, sonotohito's suggestion of creating livable underground spaces on a place like Mars isn't really far fetched, and there are no doubt people in NASA brainstorming those ideas now.
posted by Burhanistan at 1:35 PM on April 29, 2010


grizzled Actually, I meant producing underground habitats off Earth.

Practically speaking we could invest lots of time and resources into terraforming Mars and the end result would still be a dry, cold, and generally unpleasant place. Put those same resources into digging out habitats in Luna, or Ceres, or Ganymede, etc, and you'd have more living space and higher quality living space.

And yes, I really do doubt that even if we find habitable planets orbiting other stars, we'll colonize them. It sounds nice in Heinlein books, gives the authors excuses to write stories with grizzled pioneers fighting off bug eyed alien monsters, and makes no sense at all.

Every habitable plant is at the bottom of a giant gravity well. You'd need a beanstalk or something similar to get stuff up and down efficiently, and in the end you'd have a planet with its propensity for climate change, etc. Why not just live in space where the climate is under your control? No bugs in your farms, no weeds, no atmosphere getting in the way of collecting solar power, etc.

When you get down to it, planets are nice places to visit, but you probably wouldn't want to live on one.
posted by sotonohito at 1:44 PM on April 29, 2010


DNA is just a complex machine created by aliens for purposes of colonizing the galaxy. If you want to ensure the survival of life and culture it is only logical that you would develop an organism capable of evolution through natural selection in many environments. Once there the process of specialization and evolution will develop food sources, extract minerals, creates oxygen and adjust the atmosphere to allow more complex forms of life until ultimately intelligent life evolves.
posted by humanfont at 2:15 PM on April 29, 2010


Any Star Trek fan will tell you that in the future, even if we develop FTL travel, artificial gravity, teleportation, and a post-scarcity economy, we'll still only colonize a handful of planets. Borg invasions, time-traveling Romulans, etc. may come close to destroying our entire species, but Earth is our home, and there's no place like home.
posted by Thoughtcrime at 2:52 PM on April 29, 2010


Sure, until the Xindi superweapon blows it up.
posted by The Winsome Parker Lewis at 2:58 PM on April 29, 2010



Every habitable plant is at the bottom of a giant gravity well. You'd need a beanstalk or something similar to get stuff up and down efficiently, and in the end you'd have a planet with its propensity for climate change, etc. Why not just live in space where the climate is under your control? No bugs in your farms, no weeds, no atmosphere getting in the way of collecting solar power, etc.


You make some interesting points, but I wouldn't write off planets just yet. Some of the obstacles you mention are pretty trivial when compared with the central challenge of getting, say, a sizable contingent of people to anywhere outside of our own solar system; others (like an atmosphere) are potentially as much a help as a hindrance.

Let me be a little more specific here. First: yes, planets are gravity wells. Yes, it's not particularly efficient to move things from orbit to a planetary surface and back. But, from the standpoint of our awesome future selves who have somehow miraculously figured out how to travel between the stars in a reasonable amount of time, who the hell cares? The energy cost to put something into orbit around an Earth-like planet is ballpark 100 mega-Joules per kilogram. The energy cost to get that same kilogram mass to something of order the speed of light (which, if you want to traverse any meaningful between-the-stars distance in a not-insane amount of time, is something you will somehow have to do) is 10^11 times greater. Figuring out the latter problem means not caring (much) about the former.

Second: I am not sure what you mean by planets having a "propensity for climate change." Do you mean local, sudden weather events? Hurricanes, earthquakes, etc? If so, our space-faring descendants can move to another patch of new-Earth; this is, again, pretty trivial compared to what they went through to get there. Or do you mean global-scale climate change that would render a whole planet inhospitable? If so, I'd argue that it is at least as difficult to envision a space-based craft that would be stable and self-sustaining over those same timescales. What happens when something breaks? Sure, you've carried a billion spares, and have the tools to create most things you need -- but ultimately (i.e., on very long timescales) what you need will be raw materials. Minerals, for instance. Space has very little to offer in that regard; even garden-variety planets have more. Which leads us to

Third: Space is pretty much the least hospitable place out there. No planet's surface is colder, or subject to more extreme temperature variations; no planet offers less air to breathe or water to drink or minerals to mine; no one on a planet's surface is more exposed (than a craft orbiting it) to bombardment by micrometeroids or high-energy particles. Space is everything life does not need. The atmosphere you mention as an obstacle to collecting solar (stellar) power is also a partial shield (along with the planet's magnetic field) from the exoplanet equivalent of a geomagnetic storm -- and, oh yeah, might allow you to breathe without recyling or manufacturing oxygen. Every minute you spend in space ultimately takes energy -- to protect your frail body, to let you breathe, to anchor you to the floor (unless, of course, our distant ancestors have given up on gravity alltogether). Find the right planet, otoh, and you can turn off the generators.

You can argue, reasonably, that all the problems of living in space indefinitely are surmountable -- particularly for a civilization that has managed the problem of travel over huge distances. The energy you need can be collected; the parts can be made somehow; the oxygen can be recycled. I just happen to think those problems are at least as profound as any associated with living on the surface of any reasonable planet.
posted by chalkbored at 3:47 PM on April 29, 2010 [1 favorite]


Why do you think bugs would come with us 'on planet', but not in a "space ark" wouldn't they follow us wherever we go?
Not that I disagree with you on that idea long term, creating material to shield from radiation is much easier than 'building' a radiation stopping atmosphere... shallow salt water 'seas' with cyanobacteria might be needed to kick start a hypothetical second stable O3 (Ozone) bearing atmosphere. Transitioning to some people living in and on the ocean we learn how to utilize such fast and wide spreading organisms (their genes may be useful to us as we can 'steer' evolution, even by processes as simple as 'artificial selection' in organisms to aid us as we hypothetically spread to space).

But since it's all about space with this, what then will be the short term goal? How do you propel past stagnation, towards that sort of technology, grizzled, I was just joking about the asteroids missing mars, and it hitting earth, because of standards errors (really happens by accident, no dr. evil needed) what you describe is accurate, to 'offshore' some of earths population it would start with those massive 'floating cities' that were originally created as offshore airports, originally for a Chinese city I think, then building slowly downwards... the power of tides, waves and the ocean and energy transfer of varying temperatures, as found at thermo-clines is much more reliable, and consistently harvest-able than wind or solar currently is.
Geothermal harvesting... well, I guess that we are hoping that this hypothetical 'underground extraterrestrial living space' is on a tectonically inactive planet. Underground living seems risky, aren't 'young planets' like I am guessing would be sought, usually shifting and re-forming.

Another joke is that we have 'choice' about our places of living going underwater, the feedback loops in climate systems mean that the massive quantity of human life sustaining 'fresh water' currently locked in glaciers, is melting into and mixing with the salt water oceans... imagine a tepid, or warm bath... now add 63% of the total warm bath water again, but this time it is ice cube water that is from freshly melted ice cubes... this changes the dynamics of the bath, right? Global Climate Change is not as simple as hotter, or colder... what it is is greater shifts and swings, faster switches between hot and cold. A rise in uncertainty factors. Droughts like the dust-bowl (which wasn't "predicted" and left massive devastation, unusable desert like topsoils, and a removal of all the vital nutrients from the soils that remained, also faster water evaporation) in early 20th century in the prairie provinces and several states, in combination with the "arctic magnification of changes effect" and the melting of significant quantities of glacial ice... and suddenly we have crisis in a near term... this is not sci-fi, or fairytale storytelling this is just responsible humaning to consider the long game.

No choice here, we need to develop all of the capacities that are needed to "go to space"... regardless of whether or not we in fact desire to "go to live in space".

What I am suggesting isn't like trying to move everyone immediately into a "bottom of the ocean living space" like a black and white movie world as in Sphere, or the abyss, this is starting at the surface, and building downwards, a) exploring the 75 percent of our planet we really don't know all too much at all about. b)as mentioned, finding ways of living that are in sync with the very real rigors of "space living" generally... and "DEEPspace living" in particular. Like, any talk that doesn't have us changing and experimenting with our societies, and learning new ways of living and new ways of interacting, and new ways of sustaining our basic needs and functions, we are taking things as serious as describing "bug aliens and extra galactic space colonies"; There is none of themassive energy expenditure costs of "digging" into geological material with water. If we don't create new ways of purifying salt water soon we are in trouble. Maybe geneticists could design an organism that "collects salts by accretion" like the shelled diatoms, and then can be dried out, or skimmed and the water left with less salts?

97.5% of 'earths Water' is salted.
Leaving 2.5% Fresh water.
Of this little puddling 2.5%, about 68% is accounted for by Glaciers (which drain directly into the salted water; once salted, it takes large energy to separate.
about 30 percent of this 2.5% pie is then made up of 'groundwater', this can be drilled, or natural wells tapped, or deep underground caves... the rest, the part that we pollute into, and most of us use every single day to drink, and live, is made up of a spectacular 0.4 percent of that tiny 2.5% of all the "most precious resource on earth"

Water. Cleaning, reusing, extracting energy from... water will be what brings us to the stars, literally, because 2 or possibly 3 days outliers, and we die without it. This is even faster than radiation poisoning, and an order of magnitudes faster than "species death" by too many mutations passed on to the descendants in a "space ark".

As everyone points out... space is cold, dark, lonely and very dangerous.
And except in Sci-fi, and hypotheticals, there is nothing reachable out there.

The life filled unexplored oceans meanwhile? Where else can we start to "urge upon those among us who are willing" the lives of "pioneers" of the surface, and deep-sea.
If we can't do this on the seas, living in communities, creating situationally appropriate norms, customs and society... or if we can't yet manage to easily live sustainably in a place like the middle of the empty quarter without trucking or flying in any resources... we are kidding ourselves to think we are prepared for the stress or the hardships of any kind of space travel, and especially long flight, deepspace travel, that doesn't have us "coming home", to "jump straight to 'new planets' or space arks" without upgrading a variety of things first... I am skeptical.

Basically if we want to go to the stars, to be honest we have about to 'develop' as much compared to our current state, as would be the difference between ambulocetus the walking whale, and the sperm whale at great depths, depicted in this handy chart.
posted by infinite intimation at 3:57 PM on April 29, 2010


Of this little puddling 2.5%, about 68% is accounted for by Glaciers (which drain directly into the salted water; once salted, it takes large energy to separate.

Fortunately this energy is free and plentiful!
posted by mek at 5:32 PM on April 29, 2010 [1 favorite]


With such extensive replies to my previous comment, I don't have time for a comprehensive reaction. I will reply, however, to the above comment by infinite intimation, that except for sci-fi and hypotheticals, there is nothing reachable out there. Given the fact that men did land on the moon in 1969, we know that there is at least something out there that is not entirely unreachable. Of course, landing on the moon and colonizing it are two quite different levels of difficulty, but I would say that we at least have proof of principle. But realistically, I think that the human race at this time has such pressing political, economic and social problems that it really cannot spare the resources to undertake any ambitious efforts in space - even if such efforts might, eventually, prove essential to solving the big problems on Earth. Space is hard to get to, but it does contain vast resources.
I could also point out that we already have significantly better technology in the year 2010 than we had in 1969 when we first landed on the moon, and there is every reason to expect that as long as technological civilization survives, it will continue to advance. So what is unrealistic today is going to be more realistic eventually, unless civilization collapses and our forward progress is halted (which is easily possible, or even likely). But then, that is a hypothetical. Realistically, yes, at the present time there is nothing truly reachable out there.
posted by grizzled at 5:46 AM on April 30, 2010


chalkbored wrote Some of the obstacles you mention are pretty trivial when compared with the central challenge of getting, say, a sizable contingent of people to anywhere outside of our own solar system;

Absolutely true, which is why I wasn't talking about establishing extra-solar colonies, but rather extra-terrestrial colonies.

Even merely extra-terrestrial colonies will take tremendous resources simply to get the initial colonists in place, no doubt. The biggest problem is getting the people to Low Earth Orbit, once in LEO things become much simpler.

A catapult could help with getting sturdy things into LEO, but since colonists aren't very valuable as strawberry jam, we'll need to use gentler methods of getting them up. A beanstalk is elegant, theoretically quite efficient, and right now not really within our technological grasp. Some sort of SCRAM equipped spaceplane seems to be the best option at the present. And even at that it'd be quite expensive to ship many people up.

But, from the standpoint of our awesome future selves who have somehow miraculously figured out how to travel between the stars in a reasonable amount of time, who the hell cares? The energy cost to put something into orbit around an Earth-like planet is ballpark 100 mega-Joules per kilogram. The energy cost to get that same kilogram mass to something of order the speed of light (which, if you want to traverse any meaningful between-the-stars distance in a not-insane amount of time, is something you will somehow have to do) is 10^11 times greater. Figuring out the latter problem means not caring (much) about the former.

As I said, I was thinking mainly in terms of colonizing our solar system, not interstellar colonization.

Barring some sort of magic I strongly suspect we won't be building any sort of interstellar transport system (I've been convinced by Stross that, absent magic, the concept of a "starship" is so wrong that thinking in those terms prevents us from really addressing the problem) for quite some time, centuries perhaps. Barring magic I don't think we'll ever see common interstellar travel, and we may never see canned apes being shipped between stars.

I am not sure what you mean by planets having a "propensity for climate change." Do you mean local, sudden weather events? Hurricanes, earthquakes, etc? If so, our space-faring descendants can move to another patch of new-Earth; this is, again, pretty trivial compared to what they went through to get there. Or do you mean global-scale climate change that would render a whole planet inhospitable?

Both. Earthquakes, tidal waves, tornadoes, etc, all make planet based living rather unattractive in the short term, and in the longer term global changes to climate make planet based living even more unattractive. It isn't so much the idea that people can't deal with those problems, as the idea that I think they'd find dealing with those problems to be unappealing and would choose to simply avoid the problems by not living on planets. Vacations? Sure. Live there? Not a chance.

If so, I'd argue that it is at least as difficult to envision a space-based craft that would be stable and self-sustaining over those same timescales. What happens when something breaks? Sure, you've carried a billion spares, and have the tools to create most things you need -- but ultimately (i.e., on very long timescales) what you need will be raw materials. Minerals, for instance. Space has very little to offer in that regard; even garden-variety planets have more.

Raw materials are readily available from low gravity sources, with the added bonus of no need to worry about environmental concerns while mining. I don't think that will be a problem.

Of course any artificial habitat would require maintenance, but it's completely under the control of the inhabitants, which I think would be quite appealing. If it breaks its your fault, if the climate suddenly shifts that's just the universe being a meanie. I think the problems of the former are more appealing than the latter.

Space is pretty much the least hospitable place out there. No planet's surface is colder, or subject to more extreme temperature variations; no planet offers less air to breathe or water to drink or minerals to mine; no one on a planet's surface is more exposed (than a craft orbiting it) to bombardment by micrometeroids or high-energy particles. Space is everything life does not need.

To be pedantic, space isn't cold it's nearly perfectly insulated. One of the major problems is getting rid of waste heat, actually.

I think we've been somewhat miscommunicating, you appear to be thinking in terms of purely artificial environments (O'Neill type colonies perhaps), while I'm thinking more of burrowing into asteroids, moons, etc. Free particle and radiation shielding from the rock.

I will add that one of the major advantages of life off a habitable planet is cheap and steady solar energy. Living in space takes energy, and there's a crapload of it out there waiting to be collected and used. Honestly I think energy is a bigger problem than most others we face, it's practically a universally fungable resource. We don't colonize the Gobi desert because, in the first place, its the property of the People's Republic of China and most people don't want to live under the not quite so nice and friendly rule of the PRC, and also because we don't have any handy source of cheap energy. Even in the Gobi solar power is completely unavailable half the time and variable the other half, that makes colonizing problematic to say the least. Given a steady and cheap source of power you can burrow, dig tunnel farms, etc. Without that steady and cheap source of power you're SOL.
posted by sotonohito at 7:01 AM on April 30, 2010


The World's Largest Telescope Will Look for New Earths
posted by homunculus at 2:41 PM on April 30, 2010


-As I am unable to parse if you are opening up the set up for an awesome homeopathy joke, or gently mocking my exuberance and occasional jokey tone in talking about space exploration and how to get society to the point where we are ready for that responsibility, I will assume setting up, and will attempt a spike... I attribute this to the "chapter one" in the pdf being written in comic sans.


Of this little puddling 2.5%, about 68% is accounted for by Glaciers (which drain directly into the salted water; once salted, it takes large energy to separate.

Fortunately this energy is free and plentiful!


Right, of course it is free... we just need to keep adding fresh pure water to the ocean, slowly over time diluting it, eventually, it will a) be able to cure everything that ails you, and b) be pure water that is drinkable, and fully not toxic like salt water is.
amirite?
Have we ever done large scale, realistic "trial runs" of a "long term spaceflight"? I remember the Russian attempt that didn't wendel. And had the "crew" ending the mission in fisticuffs...
All of the observable Universe is filled with photons that were created during the Big Bang, which is known as the cosmic microwave background radiation (CMBR). There is quite likely a correspondingly large number of neutrinos called the cosmic neutrino background. The current black body temperature of this photon radiation is about 3 K (−270 °C; −454 °F). Some regions of outer space can contain highly energetic particles that have a much higher temperature than the CMB.
...so, relatively cold, dark, lonely and very dangerous.
And except in Sci-fi, and hypotheticals, and the moon, (but we have no methods of living outside of our biosphere for long periods of time), there is nothing (immediately, short term) reachable out there.

When I said cold, I guess I meant being "in" space "unprotected" (suggesting only that we don't "value" as strongly as we maybe ought to, our own "atmosphere", and the protective barrier that is right above us), nor do we properly treat our biosphere. For all that these sort of discussions are extremely exciting to me, I fear that "we" (society as a whole) don't respect, or give "valuation" to 'nature' equal to what is "freely" provided for us.


What if we had to "pay" for the "service" of an ionosphere... or "pay" for the "service" of having oxygen available to our lungs... or....
Suddenly the problems [actually basic functions of life] seem unaffordable... unreachable... unattainable.

When you ask these questions, and start putting dollar values to these "services" provided by natural processes, the realities of long distance space travel, or any kind of "off planet resource capturing" with our current level of tech show their difficulties; why not work on the problems here, inside our gravity well, where there is one less "barrier to entry" (no need to have "already" built super high tech long distance travel technologies, and "forever" spaceships, and "super power sources"; there is no need to be "in space" to work on learning how to live in space.

However; if "life" can solve these very problems and challenges that seem "too big to face" for us today, with just "time" and "some proteins mixing together"... I am pretty confident that we have the "raw materials" needed for humanity to take further steps outwards into the universe.


I have seen many mentions of solar powering for interstellar vessels, and the abundance of solar power... isn't solar pretty much useless for most of this distance from "just past pluto-->the edge of the next solar system"?

Now I am very curious if there is anyone else who see's value in "decoupling" the "methods and tools for getting into orbit" project, from the "how can we live sustainably enough to exist in outer space without easy access to all of the freely provided resources of Earth's biosphere" project?
posted by infinite intimation at 10:04 PM on May 2, 2010


infinite intimation wrote isn't solar pretty much useless for most of this distance from "just past pluto-->the edge of the next solar system"?

Actually solar power is pretty much useless past the orbit of Saturn, and not all that useful past the asteroid belt. Out by Pluto the sun looks like a kind of bright star, there isn't enough solar flux out there to do anything at all with.

As for powering interstellar transport systems solar power could, in theory, still be used but in a kind of backwards way. Build some big collectors close to the sun and use them to power a laser that in turn pushes the solar sails of the vessel. Not exactly practical anytime soon, and subject to many technological problems.

When I said cold, I guess I meant being "in" space "unprotected" (suggesting only that we don't "value" as strongly as we maybe ought to, our own "atmosphere", and the protective barrier that is right above us)

Again, it depends on where you are. If you popped out the airlock without a suit in Low Earth Orbit you'd boil in your own juices. Out around Pluto you'd eventually freeze solid, but it'd take a while because the only way to get rid of heat is radiation and heat doesn't radiate out as much as you might think.
posted by sotonohito at 3:57 AM on May 3, 2010 [1 favorite]


As far as radiation goes, and it is a big problem, it's a problem that is easily avoidable if you colonize a moon, asteroid, or other low gravity body. Burrow underground and let the rock shield you from the radiation. Not so easy for completely artificial habitats, which is why I suspect we won't build any for a while. In the long term, if you've got a Lunar colony, you can get enough material shield an artificial habitat. It'd be ugly but just covering it with several meters of Lunar rock would do the trick.

And except in Sci-fi, and hypotheticals, and the moon, (but we have no methods of living outside of our biosphere for long periods of time), there is nothing (immediately, short term) reachable out there.

Depends on your definition of "short term", Luna has to be colonized first, but once you've got that done building vehicles to get to Mars or the Belt will be much less expensive. The real cost is simply getting enough material, colonists, etc out of Earth's deep gravity well, once that's done the rest is vastly less expensive.

As for living long term, yeah, that's a problem. The Biosphere 2 project failed, though I argue it failed because it was simultaneously too ambitious and yet not ambitious enough. They tried to recreate 6 complete biomes in a tiny area. You want to recreate six biomes, you'll need a much larger area than Biosphere 2 tried. If they'd gone for the more reasonable goal of trying to produce one single sustainable closed environment I think they would have succeeded.
posted by sotonohito at 7:58 AM on May 3, 2010 [1 favorite]


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