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European Scientists Make a Case For a Return To the Moon
MarkWhittington writes "While the official target of NASA's space exploration program remains exploring Earth approaching asteroids, the case for a return to the moon has been made from a variety of quarters. The most recent attempt to make a case for the moon is in a paper, titled Back to the Moon: The Scientific Rationale for Resuming Lunar Surface Exploration, soon to be published in the journal Planetary and Space Science."
Please link to the actual journal submission, not some article from the Yahoo! Contributor Network...
Since "European" scientists are in board, maybe the Obama administration will agree to it.
LK
"Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
To me, there's incentive enough to return to the moon simply because of the research and development that would occur. The space program that sent us to the moon the first time brought forth incredible advances in all kinds of areas. We should keep pushing our own boundaries and explore the unknown not simply because it's there, but because we have the opportunity to develop stronger / more efficient / less expensive / generally better tools at the same time. Make the results of the new research available to the public at large and everyone benefits.
It's a use of my tax dollars that I can support without reservation.
Love sees no species.
The US is spending 25.7 billion (17.7 billion NASA, 8 billion for the military (GPS, etc)) on space in 2012
ESA spent 4 billion Euros (about $5 billion)... a total of 413 million EU on human space flight.
There's a lot of talk in the paper about "global" exploration of the moon. I can only assume that means they don't plan on increasing that.
We need kids engaged in science and exploration, not killing terrorists or idolizing warfare. Bring back the coolness of space exploration and the meaning of the word "hero"
One way or another humans will render the Earth uninhabitable by humans. Sooner or later.
The only way to give humans a chance to survive our own suicidal idiocy is to colonize other places. The Moon is the obvious necessary step towards that.
There's plenty of other reasons to make it worthwhile until the Earth is done. But let's get started already. There's a chance that spreading somewhere else might take the pressure off and postpone the inevitable down here.
--
make install -not war
1. Mobility: humans are more mobile than probes. This ignores the fact that, for a fraction of the cost of sending a human (say 50%) a robot could be developed and sent which was far more mobile than a human. Robots also don't need to be trained or selected - astronauts have a fixed cost per unit that doesn't reduce significantly by volume - 10 astronauts cost approximately 10x as much as one astronaut. Whereas the per unit cost of a robotic probe reduces per unit at volume - building 10 probes doesn't cost 10 times as much as building a single one.
2. Presupposing that humans are better at drilling than robots. However, this fails once again to take into account that the constraint is the size of the drill - human missions require larger rockets, which coincidentally allows for a larger drill to be carried. Robotic missions launch with smaller rockets. Solution: use the big rocket. Launch a couple of probes at once, with big, capable drills. No need for the spurious meat bag attachment.
Forget the space race, let the space rush begin! Let's mine some asteroids!
Seriously, once space exploration can be economically self sustaining, self perpetuating, then maybe we can get somewhere.
Long ago, someone once said, "Man cannot fly." And in the sense he meant it, it is still true today.. You can't flap your arms and propel yourself like a bird. However, mankind has learned to fly to the moon, something no bird could every do. In the same sense, man will not live on the moon or any other planet. Our physiology is too delicate for alien environments, even if we find one with nearly identical atmosphere and climate. We would be as welcomed as any foreign body (think 'War of the Worlds'). To get a very faint sense of the challenge, move to Mumbai or Bangkok and start drinking the tap water and eating their fresh food. Of course, the challenge will not stop us from trying.
However, as technology advances, it will become so much cheaper to send a machine, which can be built for space, that humans will always be a prohibitively costly payload. Sure, there will be a colony on the moon, but people will not thrive in a pressurized can at 1/6th our gravity. Mars, too. However, machines can be built for those environments. As they become more sophisticated, they can adapt, too. At some point, they may evolve to become indigenous.
Humans may evolve, too. However, our inherent advantage, created by billions of years of evolution, may tether us to this planet forever. Not a bad thing, either. At the point when what we create evolves beyond what we are, it may not make a difference.
the growth in the economy creates good paying jobs and tax revenues for the government, which may well be sufficient to erase the induced deficit (this is what happened with military spending during WW II)
Um... no. You aren't creating tax revenues for the government because everything is taken from tax revenues... from the government. By your logic I should employ myself and write myself checks and make myself a millionaire! The decreased deficit from WWII came because the dollar became more worthless because tyrant-in-chief FDR stole the nation's gold and revalued the dollar (and declared gold clauses illegal) meaning that the amount of money the government had to pay for any contract denominated in dollars (which all domestic contracts had to be because gold clauses were illegal) decreased. The government in essence declared that a pound was not worth 16 ounces but instead only worth 9 ounces.
Taxation is legalized theft, no more, no less.
Yes, Mars. But, the moon is closer, cheaper, easier. The moon also provides a staging point from which to launch to Mars, and points beyond. Unless I am seriously mistaken, infrastructure and assets on the Moon won't degrade, or at least will degrade very slowly compared with infrastructure and assets built on earth.
The moon is a very valuable resource, and development of that real estate should commence immediately. The moon is no longer a "goal", but a "waypoint".
The only reason we don't have multiple bases on the moon now, is that mankind has it's collective head up it's collective ass. My nation, which actually put men on the moon, wastes more resources on the invasion of other nations than it would have taken to build and maintain a base capable of housing 1000 personnel. Of that much, I'm certain. I suspect that said base could be much larger, and that maybe a few satellite bases might have been built with all the money wasted in Viet Nam, Iraq, and Afghanistan. Some of our lesser actions could probably have paid for one of those small satellite bases.
Oh yeah. Read my third sentence again. Points beyond. To me, Mars should just be considered a practice mission. Plant a real colony, close to home, for practice, so that we can do the same further out. We NEED to spread out, so that a single epidemic, or a catastrophic event doesn't wipe us out!
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
Papers such as these are great at pointing benefits, but do little to address costs. The question is not, is going to the moon useful, but rather, is going to the moon worthwhile?
I have become very skeptical of governments taking on such well-intentioned programs as governments are ill-equipped to evaluate such trade-offs as they do not collect the benefits or bear the costs. Instead, governments collect the benefits of appearances (as opposed to actual success) and shift the costs.
If those scientists can convince Buffett or Gates, there is a chance the proposal makes sense. If the can convince politicians, fat chance.
These comments are mine; I do not speak for my employer.
Energy gathering, asteroid mining, making materials maybe too complicated to do in a planet, or just manufacturing with the resources gathered up there, thats a more direct and shorter term return of investment, if you could do things that would please both people that care about knowledge and people that care about money, then better. And could ease things for future moon missions.
The moon would make a lousy staging point. Why loft things out of a gravity well, then drop them back in, only to loft them out again. It is an utter waste of time and propellant. Assemble stuff in Earth orbit, then go directly (or as directly as orbital mechanics lets you go).
When our name is on the back of your car, we're behind you all the way!
This. The moon doesn't really have much going for it but 'fairly close'; if you want a staging point, you're far better off with a space station of some kind. That way, you're not only even closer then the moon, but you don't have that pesky gravity well imposing an additional cost.
ESA is not the EU's space program, it's the all-European space program.
We NEED to spread out, so that a single epidemic, or a catastrophic event doesn't wipe us out!
There's no realistic way of spreading beyond Mars. And Mars itself isn't really a better place to survive a catastrophic event. It would make more sense to build a couple of deep underground (or underwater) bunkers on earth, where a few people can take shelter from this catastrophic event. It would be several orders of magnitude cheaper, and more effective. At least, when the event has passed, you can climb out, and breathe the air, drink the water, and grow food.
But it has gravity which makes it easier for humans (less bone loss).
Underground lunar facilities would provide shielding against cosmic rays (also better for humans).
There's *stuff* on the moon we can mine & use on site (as opposed to launching it from earth).
If we can refine fuel and materials from lunar ores (possible, in theory) then the moon would make a great staging point to fuel up or perform final assembly for long missions. Instead of trying to lift obscene quantities of fuel and finished materials out of a much bigger gravity well, you just boost up the hard to build stuff with as little fuel as possible, and then slap it all together with moon-tape and ExxonMoonble.
It would also be much more durable than an orbital station, especially if it's partially subterr.. uh, sublunar.
Basically, the argument is that it would be the better long (long) term investment that would eventually pay itself off. And heck, maybe there's an argument for doing both and baby-stepping our way into space (earth->orbit->moon->phobos->titan->???->orion slave girls!!)
Dude, paying 2m people to build a space station/and infrastructure is way better than having 2m cafe workers, or 2m tax accountants, or 2m cops, or 2m parking insepectors, or 2m taxi drivers.
If you attempt the impossible, then you create new industries, new techs, new methods, and learn stuff.
Now go back to your C-64 and be happy with the same tech forever.
Liberty freedom are no1, not dicks in suits.
What if the 'event' takes generations to pass? Or never passes at all? Sure we don't have the technology to easily survive on Mars/Moon right now, but we'll need to develop it eventually, or go back to living in log cabins once resources on Earth run out.
Read the balance report.
All income taxes, (not much really), all goes to pay of all bank loans.
All your paid for services come from corporate taxes, sales taxes, business taxes, trade taxes, local taxes and fines.
So what does modern govts pay for?
Nothing, I have to pay for everything.
Parking
Food
Gas w/taxes.
Lawyers arent free, all cost $.
Most education isnt free any more.
Most medical services arent free, or the crap ones are free. Good ones cost an arm or leg.
Public transport, mostly privitized now, and isnt cheap.
Nothing is subsidized for the average man.
Who gets the goodies?
Old people and their discounts.
People with children and their tax discounts, so they pay no tax.
Corporates and their 'discounts in tax rates'
Big corps, who get electricity 1/3d retail price.
Disabled people.
Illegal immigrants get lots of shit free.
Over the last 15 years, ive paid for everything, the govt has paid crap all. And your local upkeeping is just based on local city taxes from services.
Liberty freedom are no1, not dicks in suits.
What's so special about this technology that it will let us live on Mars in luxury, but condemns us to living in log cabins on earth ? Why won't the resources on Mars run out just as they do on earth ?
Sure they'll run out, but it will give humanity time to figure out how to expand to the next pile of resources, AND give us experience in extracting them in non-terrestrial conditions. Or we can wait on Earth for a few hundred years, until resource depletion and resulting wars make it impossible to ever develop the technology we'd need.
If we can refine fuel and materials from lunar ores (possible, in theory) then the moon would make a great staging point to fuel up or perform final assembly for long missions. Instead of trying to lift obscene quantities of fuel and finished materials out of a much bigger gravity well, you just boost up the hard to build stuff with as little fuel as possible, and then slap it all together with moon-tape and ExxonMoonble.
All other things equal, yes. Unfortunately heavy mining equipment usually depends on big diesel engines that need diesel and water as coolant, neither of which are easily available on the moon. So for power we'd need great fields of solar panels or something similar and without coolant dry mining would require far more frequent changes of drill heads. Then you have the same issue with smelters, they require huge amounts of energy so add more solar arrays. Then you need huge hydraulic presses to make it into sheet metal, again another power hog so add even more solar arrays. And we still only have sheet metal.
Ore mining is heavy industry, like really heavy industry. Here on earth it seems so basic, only costing a few dollars but on the moon it would actually be a very, very complicated and expensive project. It would be a great achievement if we even manged to create fuel for an empty return rocket, mining ore is extremely much harder. And even if we could do that, it wouldn't make sense to send a rocket down to the moon to bring fuel back up, only make it a bit cheaper to do a moon mission. Going directly to Mars really has few disadvantages that I can see.
Live today, because you never know what tomorrow brings
Moons, asteroid belt, orbital stations. No other place to go at all. And if we get good at making those, there is no reason not to build a generation ship and start exploring the galaxy. Yes, humanity is going to end, but there is no reason not to try and make that end distant as possible.
I think you are approaching the mining problem from a wrong perspective:
:-)
From all that you say, the conclusion should be that we need a small solar panel factory first. And in order to mine its raw material, we need to tape a shovel to its side so the astronauts can shovel regolith dust into its input funnel.
No need to start launching or building something like Bagger 293 until you have a need for 240 000 m^3 of raw material per day!
Assuming the production needs are for one or two buildings and a dozen small rockets per year, a "fool's stick" (metal shovel on one end and a fool on the other) should suffice for the ore collection phase.
Maybe a small table-top factory that can produce a crude amorphous Silicon solar cell the size of a large button, with Calcium or Aluminium wires, can be built somehow(*). Then you need a small robot to arrange and solder the solar cell buttons outside in the sunlight and presto, you've got a growing power source.
Time is probably much cheaper in the beginning than raw power. Germany built those Bagger (in German) things because their heavy industry in the Ruhrgebiet had a large need for "Braunkohl" in the '70s. On the Moon you only need industry for your own base and maybe to launch volatiles and fuel to Moon orbit where they can be tugged to orbital destination or attached to a large (Mars) rocket.
Apropos, anybody here on Slashdot who actually read De Re Metallica by Georgius Agricola? I'm a bit too lazy, but that level of technology (16th century) probably gives hints for energy-appropriate resource extraction methods. Although fire and water are probably hard to come by on the Moon
I've got the modern English translation from Project Gutenberg but haven't got around to studying it yet.
(*) Please disregard the hand-waving.
To be, or not to be: isn't that quite logical, Slashdot Beta?
I am pretty sure that "no realistic way" only means that "I can't imagine how we might accomplish this".
By "realistic way", are you referring to the technological status of the tenth century, the fifteenth, the twentieth, or the twenty fifth centuries? Personally, I'm here in the 21st century, and today's technology seems to be up to the task of putting men anywhere in the solar system, if we choose to put them there. What's lacking is the desire, the drive, to put them out there.
You will note, please, that I did not say that we could put men anywhere in the solar system, and at the same time make them comfortable, happy, wealthy, or even guarantee a return trip. I merely say that we can put men there.
But, that is really beside the point, right now. There are a number of missions that are better done via robotics, before we actually get serious about colonies, anywhere beyond the moon. And, we're at least 50 years away from giving serious consideration to a colony anywhere beyond Mars.
What's needed is, a sense of mission. The longest journey begins with a single step, and we've not yet taken that first step.
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
Bingo. You've said it all. Mr. ongelovigehond appears ready to give up, roll over and die at the first sign of adversity.
"Oh, my home has been destroyed by (fire, flood, war, famine, global warming, giant asteroid, invasion of yucky viruses from Andromeda - any or all of these) so I'll just roll over and die, and tell my children to do the same!"
His monkey ancestors would be ashamed.
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
Since the rest of the solar system is even more hostile than Mars, "beyond Mars" was referring to interstellar travel. In addition, today's technology isn't up to the task of setting a man on the surface of Mars without killing him. Maybe you mean technology that we could potentially develop in the next decade(s) if we put a lot of effort in it.
I believe that you are wrong. We have the technology to put a living man on the moon. So far, we simply have not engineered the mechanism with which to do it. We have the same sort of rockets that landed men on the moon, repeatedly. Said rockets, beefed up to deal with Martian gravity, could certainly do the job. Not to mention, parachutes and/or wings will work on Mars. The atmosphere is different, but there is an atmosphere. The glide ratio may suck, but there is a glide available. We have the tech, we just need some engineering.
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
The moon is great for things that require a lot of support infrastructure to produce...
The moon is terrible for things that require a lot of support infrastructure to produce...
FTFY
When our name is on the back of your car, we're behind you all the way!
Oh, so now you want not only to drop stuff down a gravity well, but you want to bury it as well. Perhaps you think you can land on the moon and dig your way to Mars?
When our name is on the back of your car, we're behind you all the way!
Landing in a vacuum is easy using a rocket engine. That's proven technology. Landing in thick earth atmosphere is also proven technology. Landing exhaust flame first with supersonic speeds through the Martian atmosphere, with unpredictable side winds, is unexplored territory. Heat shields, parachutes and wings need to be really big on Mars to be effective in the very short time it takes from orbit to surface. Unfolding really big structures and keeping them intact at supersonic speeds is also unexplored territory. The glide ratio sucks so bad that with earth-sized wings or parachutes, you'll still be going supersonic when you crash into the ground. I agree that in theory it's just a matter of engineering, but it's quite difficult engineering, and you can't really test it anywhere else but on Mars, which makes it rather expensive and time-consuming to try out different ideas. That's why a manned landing would probably take a few decades.
What rocket parts are you going to build on the moon? Seriously? Rocket engines are hand made from special alloys and ceramics, and precision machined parts. Guidance computers: They need refined copper, tantalum, aluminum, carbon, plastics, and of course, pure silicon. The easiest parts to build would be the fuel tanks, and that would take aluminum, lots of aluminum. Lots of aluminum will require cranes, and hydraulic presses and machinery, all of which would have to be shipped up from Earth. Of course, by the time you've shipped them up, you've got lots of unused fuel tanks sitting around.
By the time you get a rocket built out of lunar materials, we would have been on Mars for 50+ years.
When our name is on the back of your car, we're behind you all the way!
It's not like the energy needed to get into space is all that expensive. The only reason spaceflight is as costly as it is, is because we have a thick atmosphere to go through to get there. In order to keep heat and drag losses down, we have to go straight up, and hold off acceleration until we get through the thick stuff. If we didn't have that atmosphere to worry about, launching from a magnetic rail several hundred kilometers long would cost a couple orders of magnitude less than our current chemical fueled rockets.
That's exactly what we have on the Moon. You mine all your structural materials (aluminum) from the Moon. You build the thing on the surface of the Moon. You magnetically launch the whole gargantuan craft into orbit for dollars per kilogram, with a modest apogee kick motor. Launching from Earth sucks. Anything we can do to reduce how much we launch from Earth is a good thing.
Yes. You can make a decent cement out of Lunar soil. Send robots up first to manufacture thick cement domes, and you have ready-made habitats, safe from radiation and micrometeorite damage. You keep talking about "dropping stuff down a gravity well". You act as if everything we use is going to need to be sourced on Earth.
So how do we go about producing this aluminum? How many tons of lunar ore do we have to extract to get one ton of aluminum? Where do we get the excavators and drills to extract this ore? Which explosives do we use for the blasting? Where do you get the forges to cast the aluminum, the hydraulic presses to form the aluminum, the cranes to move the formed aluminum? Are you planning on having a huge pressurized machine shop to build these rockets in, or are you going to have people walking around in space suits? Where are you going to get the greases, and the ceramics, and the plastics, and the welders and other tools you need? Once you get it built, where is the fuel going to come from? What sort of launch facilities are you going to need? Are you going to launch right from the manufacturing site, or are you going to use some sort of crawler to take the rocket to a launch-pad?
As you say, it's not like the energy needed to get into space is all that expensive. What is expensive is the INFRASTRUCTURE and the INDUSTRIAL BASE needed to convert raw materials into usable spacecraft. We have that industrial base here. We have the infrastructure here. On the moon, there is nothing, and it will be a long, long time before it becomes more economical to launch from there rather than from here. Especially if your goal is simply to reach Mars.
When our name is on the back of your car, we're behind you all the way!
You act as if everything we use is going to need to be sourced on Earth.
Yes. For the next hundred years or so, it will be. By the time we get lunar resource utilization up to the point where it is remotely helpful on a trip to Mars, we will already have a colony on Mars using Martian resources.
When our name is on the back of your car, we're behind you all the way!
Meanwhile ISS will be abandoned in 6 months lol. Anyway our only hope is China.
We NEED to spread out, so that a single epidemic, or a catastrophic event doesn't wipe us out!
There's a slight problem with this theory. Space colonies aren't going to be initially self-supporting, so they'll require constant resupply and dependency on Earth. Even once they do achieve economic self-sufficiency, a web of shipping links are still going to remain across the solar system for tourism and export reasons. So the act of spreading out itself will create a space shipping infrastructure which will neatly carry epidemics or wars to all the different outposts. Same problem as with one planet, just magnified.
And seriously, nothing short of Sol going nova (which no appreciable space colonisation program is going to survive either) or some kind of not-yet-invented black hole weapon which could literally erase the planet will ever make Earth less habitable than Mars. Nuclear war, climate change, plague and asteroid impact combined aren't going to make space a more inviting prospect than, say, Antarctica or the Australian outback.
If human survivability were really the goal, then a much better return for investment would be funding the development of small sealed greenhouses on Earth that could be deployed to desert regions. Once we can do that at will, then we can try moving that technology to space, where it's much harder. But it doesn't seem likely that we'll ever be in the position of having a dead Earth and living space colonies. 'Cause we could always just drop a colony-pod on the radioactive post-nuclear ruins of New York (or crawl back out from the mineshafts), and voila, Earth is back in business.
You are not a brain: http://books.google.com/books?id=2oV61CeDx-YC
Bingo. You've said it all. Mr. ongelovigehond appears ready to give up, roll over and die at the first sign of adversity.
"Oh, my home has been made slightly uncomfortable by (fire, flood, war, famine, global warming, giant asteroid, invasion of yucky viruses from Andromeda - any or all of these) so I'll just survive it all like we have for 10,000 years."
Fixed.
Fire, flood, war, famine, global warming, giant asteroid and Andromedan viruses combined are never going to render Earth less habitable than Mars.
There simply isn't any actual sensible reason to go into space in order to survive catastrophe. Go to space to explore, certainly. But there's no conceivable disaster - short of a solar supernova which would also melt the rest of Sol system - that could make Earth harder to live on than any of the other planets out there.
Take the moons of Jupiter - please! Io gets 36 Sieverts of radiation a day, for and Europa gets 5. One Sievert is fatal to humans. Attempt no landing there, indeed. There's no way even a full-scale nuclear war on Earth could compare with this.
And resource failure on Earth? No, we've still got all the resources right here; it's just that we're using them. If we tried recycling rather than just tossing stuff into landfills, we'd suddenly get all those minerals back.
Manned space exploration really isn't a solution to anything except the political problem of "what do I do with these converted ICBM launchers while I'm waiting for WW3?"
You are not a brain: http://books.google.com/books?id=2oV61CeDx-YC
"...infrastructure and assets on the Moon won't degrade, or at least will degrade very slowly compared with infrastructure and assets built on earth."
Moon dust is incredibly sharp and jagged, because it isn't constantly blown by wind and eroded by water. And it's very fine, the result of being pulverized by asteroids. So you have very fine, extra gritty grit working it's way into everything that isn't hermetically sealed. Bad news for anything with moving parts.
Personally, I'd rather spend money on moon bases than on making wars and maintaining our empire, but that ain't happening.
Never let a lack of data get in the way of a good rant.
Explosives? Drills? Blasting? Rockets? Launchpads? You've got entirely the wrong idea about these things.
The Lunar soil is on average about 10 meters thick with some 8% aluminum by weight. You don't have to excavate for anything, you just scoop it right up off the ground. Refine it using various magnetic, evaporative, and electrostatic methods. That gets you large amounts of silicon, iron, aluminum, magnesium, and calcium, while small amounts of alloying metals can be brought up from Earth. Large scale refinement and manufacturing would require large scale facilities, but something small scale would not be difficult to set up. It could certainly be done within a few years, with a smaller budget than the ISS.
You don't launch from the Moon using rockets, you do it magnetically. Start small. A few dozen meters of linear motor would be enough for bulk payloads. Any surface water on the Moon evaporates and is lost, but the Moon does have sub-surface ice available for reclamation. Water means hydrogen and oxygen, which means fuel. Your deep space craft would only have to get themselves to low Earth orbit, before being refueled by cargo from the Moon. Remember, humans can't loiter around in the Van Allen belts for weeks as an ion drive slowly circles up to escape velocity. They need those high thrust chemical engines.
Keep extending that launch rail. At a kilometer or two, the acceleration is low enough to handle more complex structures. Once you hit around 100km, the acceleration is low enough to safely launch humans. The key issue is that this is not all-or-nothing. You don't need the whole massive facility in place to start reaping the benefits from it. Start slow, and build up to something bigger, all the while getting valuable experience in living on alien worlds.
It better be damn big, I need leg room and head room. I should be able to tilt my seat ALL the way back, too!
You know, never mind. Forget it! I ain't going to the moon in no damned CASE!
"Slow down, Cowboy! It has been 3 years, 7 months and 26 days since you last successfully posted a comment."
Specifically, the LRO mission demonstrated that the moon itself is a source of radiation, so burying yourself in it is probably a bad idea, unless it doesn't go to any real depth, and you are willing to seriously dig down.
http://news.discovery.com/space/moon-radiation-gamma-rays.html
-- Terry
There's a difference between caring for myself and my children, and caring for "humanity" a million years from now, especially when saving "humanity" means that a few thousand people get to go to a space colony, and the other billions can just die on earth. What exactly are you saving here ? We're letting thousands of species go extinct on earth right now without as much as blinking an eye, but we have to go through insane amount of trouble to save one particular kind of hairless ape in some unknown future ?
Perhaps, my friend, you might remember, and tell us all, how the earth came to have a moon.
If my recollection is collecting properly, I think that a giant asteroid DID strike the earth. The sumbitch was so massive, and moving so fast, that it sorta kept on going, after striking the earth, then wobbled into an almost stable orbit. I say "almost stable" because that big bastard is supposed to fall back to earth in - ohhh - I can't remember now, maybe a billion years. Maybe only a couple hundred million years.
So - question is - how "habitable" was the earth, in the first couple millenia after that big bastard did it's billiard ball act on us?
I realize that no one was around to take measurements of seismic activity, global warming (or cooling) or atmospheric properties and conditions. But, I strongly suspect that in those millenia, the earth could not support advanced life forms. I'm quite sure that it was all given over to single celled life forms, and maybe some plankton.
Now - here's a "What if" for you. Suppose that another asteroid, somewhat smaller than the moon - hell, even 10% of the moon's mass, should happen along, and hit the moon head on? A ten percent loss in the moon's orbital momentum would likely result the in the moon falling out of the sky much sooner than predicted.
Now - want to take bets on the habitability of the earth after that happening? How deep a cave do you think that it would take to protect the remnants of humanity from conditions above?
I'm afraid that, like most people, you simply think on to small a scale. The earth can be rendered less habitable than any of the frozen planets, which are all less habitable than Mars.
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
With a self replicating lunar factory of course:
http://www.islandone.org/MMSG/aasm/
With the advances in machine vision and CAD/CAM we have these days it would be fairly straight forward. We might have to ship up a fair amount of fluorine for the metallurgical stuff tho...
My nation, which actually put men on the moon
Allegedly.
Bow before me, for I am root.