The Galaxy May Have Billions of Habitable Planets 380
The Bad Astronomer writes "A recent astronomical report (abstract in Science) came out stating that as many as 1 in 4 sun-like stars have roughly earth-mass planets. But are they habitable? A simple bit of math based on some decent assumptions shows that there may be billions of potentially habitable worlds in the galaxy. '... astronomers studied 166 stars within 80 light years of Earth, and did a survey of the planets they found orbiting them. What they found is that about 1.5% of the stars have Jupiter-mass planets, 6% have Neptune-mass ones, and about 12% have planets from 3 – 10 times the Earth’s mass. This sample isn’t complete, and they cannot detect planets smaller than 3 times the Earth’s mass. But using some statistics, they can estimate from the trend that as many as 25% of sun-like stars have earth-mass planets orbiting them!' Getting to them, of course, is another problem altogether..."
Getting to them has always been the problem (Score:4, Insightful)
Charles Stross has a great article on this. (Score:5, Interesting)
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The distances are astronomical (ha ha). There's no economic gain at this point to going to the stars. Heck, we've barely stepped off our own rock.
Still, one would like to think that right now we're beginning the surveying aspects of future interstellar exploration, and as soon as the physicists deliver us bountiful amounts of cheap energy and some useful way around the speed of light, we will be better able to pick the targets.
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Energy affects acceleration - not distance traveled. How much energy you want to expend getting to another star all depends on how fast you want to get there.
Personally, I think mankind will end up using some variation of the generational ship to colonize the stars. Send out a nearly self-sufficient ship and let it travel for millenia of need be.
Alternatively, if we ever figure out how to truly perfect some form of cryogenic stasis, then you don't even need to do that. The movie Pandorum seemed to have a
Generational Ships (Score:5, Interesting)
With cryo-stasis ships, at least there's a reason to eventually settle somewhere. You want to wake up (or stop taking watches) and eventually start your new life. You can bear the hardships of the journey, because you have a personal goal that you intend to some day fulfill.
The thing about generational ships, is that if they're really self-sufficient and comfortable enough that the early generations don't go mad, then what's the point of landing anywhere? You can say that humans need to expand, but the people onboard won't be able to meet that need, and they're just going to have to cope with such a limited existence. But if they succeed, then that culture will be passed down, so you'll have a whole population that is happy staying in their little box. How can you plan so far into the future and keep the plan intact?
There's a Star Trek episode ("The World is Hollow And I Have Touched the Sky") where the people don't even know they're on such a ship, and the more I think of it, the more realistic and believable that seems. People wouldn't ever be able to stick to such a long-term mission in which they don't personally have any stake, so they might as well not be depended upon to achieve it, or even know it's happening. One single centralized authority with infinite patience (a computer) and a secret and tyrannical agenda, is about the only thing that could keep it going.
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Many of them would not need to know they're on a spacecraft. But some staff should definitely exist (an order perhaps?) that knows about the journey.
Government should be open and transparent, and the people should be informed. It makes me sad that people would even propose such a thing.
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Oh, I agree with that. It seems like an easy decision for the final 3 or 4 generations ("We're almost there! Keep going!" and "Yippee, we're here!"). But a few dozen generations before that? I can imagine people saying, "Why spend our energy on the acceleration/deceleration rockets? Let's pump it into the holodeck instead."
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Our materials technology has going to have to advance considerably. The only way some of the equipment like the Voyager probes have survived is because they are, relatively speaking, extremely simple with very low energy requirements.
You start talking multi-generation biosphere ships or cryo ships you're talking about a huge set of problems that go hand in hand with maintaining an isolated spacecraft for centuries or thousands of years, without meaningful help or even raw materials to be used to fix proble
Re:Charles Stross has a great article on this. (Score:4, Insightful)
Agreed, the focus in these discussions always seems to be on how to move the spaceship but in reality that is a minor problem with several plausible solutions. When it comes to keeping the crew alive we don't even know how to keep a biodome [wikipedia.org] on Earth from turning into a rotting cesspit after a year or two. Once we know how to do that we can perhaps use the technology to fix the (human) life support systems on "spaceship Earth" before we send a handfull of explorers to look at other planets.
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Who said anything about it still working? The issue was about the energy requirements for getting objects to other star systems, not within any particular timeframe. Voyager will almost certainly survive until it reaches another star system; maybe not with any power, but it'll be an intact object (there aren't a lot of other objects floating around in interstellar space for it to collide with).
Target practice? (Score:3, Funny)
Voyager will almost certainly survive until it reaches another star system; maybe not with any power, but it'll be an intact object (there aren't a lot of other objects floating around in interstellar space for it to collide with).
Unless, of course, it's blasted to bits by a Klingon.
just spin up the stargate and dial them! (Score:2)
just spin up the stargate and dial them!
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I think we can handle it. Especially if there are hot blue and/or green alien women there.
Re:Getting to them has always been the problem (Score:4, Informative)
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If that were the case, then we'd have to bow to the creationists and how they mock our use of fossil records to show how we descended from other species over the past tens of millions of years.
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Historical and modern genetic evidence suggests otherwise.
NASA (Score:4, Insightful)
Re:NASA (Score:5, Insightful)
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Cut funding to NASA, allow private space companies to use the R&D, blueprints and the like and watch us achieve heights that NASA never dreamed of.
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Private spaceflight has a lot of inducement to figure out how to get stuff into earth orbit, and not very much at all to go anywhere beyond that. Trust me, I know NASA people, scientists and non-scientists. They are not pointless bureaucrats. They really want to go to the stars.
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Re:NASA (Score:5, Insightful)
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Wow... I wish I could be indoctrinated so to have that kind of confidence.
Governments DO NOT have infinite money. They have a lot, but it is certianly not infinite.
And, while the government is usually inefficient, it is not always so. Likewise, businesses can be inefficient and still stay in business, depending on the competitive situation.
As far as A goes - it wouldn't stop corporate America or any other first world countries corporations, they could do the research on their own. Or are you suggesting ther
Re:NASA (Score:5, Insightful)
Government programs are /always/ plagued by waste and inefficiencies.
a) Private, commercial ventures are also always plagued by waste and inefficiencies. Humans are involved. You get what you get.
b) Just because there's waste doesn't mean it's 95% waste. That's like saying that because lightbulbs emit both heat and light, they're incapable of ever illuminating anything.
c) Grandiose statements like this one, common on the right, are faith-based attacks. It's common sense. Everyone knows governments waste. Everyone knows governments are nothing but wasteful bureaucracies. It's obvious. Duh. The only good government is a tiny one. But not nonexistent, as that might be seen as disparaging the founding fathers.
The underlying assumption is that you can only trust someone who wants to take your money for his own profit, because anything else is too good to be true. But not too much profit. So you can only trust someone who wants to take your money for his own profit in a suitably competitive market. You only trust greedy people. And then ...
The only reason why they can sometimes get things done is because they have infinite money from stealing from taxpayers.
d) No. They're not stealing. We're pooling our moneys to achieve a common goal, as we've agreed to do, through the system of laws we've previously agreed to. If you don't like it, go live in France. (I can say this because I got tired of being told to live in France when I bitched about our new motherland security overlords after 9/11.)
Government restrictions.
e) That's what it *does*. That is the function of government. All freedoms not taken away, we keep. You're complaining that they're doing their job? If not, we need to know the specific restrictions you disagree with; honestly, I trust them to have a better idea of what restrictions we need than I trust you. They have thousands of people looking at what can go wrong when some private individual decides it's perfectly safe to shoot a rocket off from his back yard to go colonize Mars. And those thousands of people? They're just private citizens, like you and me, raised in the same country, under the same flag, learning the same constitution, going to the same backyard BBQ's. They love freedom too. Freedom not to be blown up because of their neighbor's stupid belief that freedom only means something when they can be perfectly reckless.
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A) The taxpayer-funded R&D from various missions is not available to them
Why should taxpayer-funded R&D be given to a private company?
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I take it you've never worked in big business.
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It's what happens whenever you let Sophists have access to the controls over research.
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With NASA its a nickel towards a goal and 95 cents spent on pointless bureaucracies.
Sometimes bureaucracies really are pointless. Other times they're the only way you can manage something as vast and multi-generational as interplanetary/interstellar spaceflight. I fear that the pro-privatization Slashdot crowd will learn this to their chagrin in a decade or two.
Right now there are functioning NASA probes at the edge of our solar system that are nearly as old as I am (a gracefully aging 34, thank you).
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The beauty of the system is, you could always go build one of the "big corps" and get listened to, or spend all your money on pursuing space travel, rather than grouse about how other people won't fund your science fiction fantasies.
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Once we confirm "M-class" planets, we'll be ready to send manned probes.
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Never heard of the voyager probes [nasa.gov]?
Fermi's paradox. (Score:5, Insightful)
That would seem to make Fermi's paradox even more troubling. My bet is that abiogenesis is vanishingly improbable. It seems pretty reasonable to be fairly optimistic about every other term in Drake's equation.
Re:Fermi's paradox. (Score:5, Interesting)
I wonder what happens if we continue to expand our knowledge about exoplanets at the current rate but we don't discover life on another planet by the year 2100. Fermi's Paradox bugs the hell out of me. I can't see how we are unique... but I also can't see why the evidence of other civilizations wouldn't be obvious.
Re:Fermi's paradox. (Score:5, Insightful)
I wonder what happens if we continue to expand our knowledge about exoplanets at the current rate but we don't discover life on another planet by the year 2100. Fermi's Paradox bugs the hell out of me. I can't see how we are unique... but I also can't see why the evidence of other civilizations wouldn't be obvious.
There are loads of reasons.
1. How long did it take for US to come about? That's a fairly long period of time for a planet to remain habitable. Cut that time down, and you drastically reduce the chance that something like 'us' will come about.
2. What good is intelligence to life? To us, it is necessary, to life? Not really. Algae and bacteria do just fine (and bacteria in some sense can be considered immortal!) Life COULD be plentiful, and intelligent life could well be so rare that it is unique.
3. Consider what we are able to see. We can basically see forms of electromagnetic radiation. That's not too useful for picking out little bits of information that would clue us in to someone else sending out information. Our emmanations are already decreasing (if considered per-capita) We can get more done with less power via directional antennas, better electronics, and now, fiber and direct access communications. We might just not see them.
4. Interstellar travel cost compared to opportunity is well... astronomical. Barring imaginary physics, the only point to go to another planet/star is to colonize it.
Think about it, we human beings are the absolute kings of colonization. We have set foot and abode on nearly every inch of this planet in some form or scope. And even if you argue that our grasp in some areas is tenuous, it certainly isn't due to lack of drive to colonize. We ARE wanderers and travelers, but to even consider something like interstellar travel is daunting to us. Is it so surprising that something which would restrict a human from traveling would also daunt another form of life?
It's not too much of a stretch to consider that our existance is every unique even without resorting to some sort of religious justification.
If it took our planet 4-5 billion years to produce 'us', and the universe is only 14 billion years old, we aren't dealing with much time for starting over. A single asteroid collission at the wrong time and the death of a human progenitor could very well mean 4 billion years of life development resulted in no intelligent life on Earth. It is not some sort of evolutionary goal.
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All valid points. Also all speculation... just like my thoughts :) That is why I put the "Year 2100" out there. I would certainly think that if there is life to discover that we would have found it after a century of looking. This assumes we continue to grow in our capabilities at the astonishing rate we have seen over the past twenty-or-so years.
Interstellar travel is inevitable (Score:2)
We have sent probes to all the planets in our system, have landed in two of them. Once we have some way to send a probe to another star system you can bet we will.
We are quickly reaching a turning point in economics when manufacturing is so cheap that we will not be restrained by the cost of things. Looking at the world today, the richest countries do not bother to manufacture things anymore, that can be outsourced. Wit
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Fermi's Paradox bugs the hell out of me. I can't see how we are unique... but I also can't see why the evidence of other civilizations wouldn't be obvious.
The most simplest resolution to the Fermi paradox is... (drum roll)
We just happen to be first.
Or very close to be being first.
Once we (or someone close to us in the tech race) achieve inter-solar system space flight, it will be only a mater of time before the whole galaxy is colonized.
Now it might be likely that most species die off or choose not to do th
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In a galaxy that existed almost 10 billion years before the Earth cooled, I cannot imagine that we would be the first intelligence. The idea seems so preposterous as to not merit discussion.
(that doesn't mean it couldn't be right though )
Re:Fermi's paradox. (Score:5, Funny)
Re:Fermi's paradox. (Score:5, Insightful)
That would seem to make Fermi's paradox even more troubling. My bet is that abiogenesis is vanishingly improbable. It seems pretty reasonable to be fairly optimistic about every other term in Drake's equation.
We won't really know until we can detect earth mass planets, but from what I've been seeing, I believe that our planet is the equivalent of hitting the galactic jackpot.
Specifically, our huge moon. The impact that did that must of created a sort of 'second stirring', resulting in a climate different than that of Venus and Mars.
I have no problems believing that habitable planets are more than a thousand ly apart, much less habitable planets that develop sapient, tool using life forms. Right now, that's outside of our detection range. Even SETI has a range of only like 60ly, if I remember right.
Re:Fermi's paradox. --- Reapers, dude. (Score:4, Funny)
Well, there's the Jungle Hypothesis, the Zoo Hypothesis, and I'm sure a few other ones. While lack of proof isn't proof, there's also the possibility that intelligent life in this part of the galaxy only started recently.
Or you know, Reapers.
Re:Fermi's paradox. --- Reapers, dude. (Score:4, Insightful)
So that just means (Score:2)
Since I'm doubtful that humans will go extrasolar as individuals, there wouldn't be any pre-existing biosphere to deal with.
Always assuming, of course, that intelligence is really the advantage that we like to believe. Current events lend some doubt to that.
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It seems pretty reasonable to be fairly optimistic about every other term in Drake's equation.
f = the fraction of the above that actually go on to develop life at some point
fi = the fraction of the above that actually go on to develop intelligent life
I've always found these 2 to be the ones that I have trouble being optimistic about. Just because a planet CAN support life doesn't mean that it definately will. And just because life forms, it doesn't always develop intelligence (see Dinosaurs and Ancient Marine Reptiles).
We've only got ONE case study so far where this has occured, us. I have trouble b
Re:Fermi's paradox. (Score:5, Insightful)
Actually, there's one other you can be pessimistic about, and it has pretty depressing implications for us: the fraction of technological societies that get off-planet. Two big humps here:
Agression: Any species that fights its way to intelligence and technological dominance of its planet will be about as aggressive as we are. A species that is not good at stepping over what's in its way to get the resources necessary for survival is a species that doesn't survive. This raises the question: can a dominant technological species avoid destroying itself with the advanced weaponry it develops (or even inadvertently by triggering an ecological collapse) before it gets off-planet? The jury is still out on whether we'll manage that...
The Lotus-Eater Problem: About the time a dominant technological species starts to develop the necessary skills to get off-planet, it likely also start to develop the skills necessary to create *really good* simulations of reality that are "just like the real thing." Can a culture avoid the lure of just abandoning themselves in fantasies which can be made more exciting and fulfilling than anything in the real world?
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Law of Numerous Small (Score:3, Funny)
Nah, it's easy (Score:3)
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How will we know the security status of the other side? I'm not jumping to nullsec!
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Why do we assume we're unique? (Score:2)
Like everyone else.
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We assume we're unique because we haven't found anything else like us. Does that make sense?
One circle of life existed 65 Million years ago for far longer than we have been alive and yet they didn't develop the intellect to construct anything. We look at the other parts of life around us that are just beginning to use tools - but they're still a long ways away from reaching where we were a million years ago.
Given that we've only been able to study these two sample cases, and both suggest that we're "above a
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We look at the other parts of life around us that are just beginning to use tools...
Actually I would put forth that we are just really really good at killing anything that might even remotely be a (tool using) competitor. Take Neanderthals for example; they had cave art, tools, and bigger brains than us, and I'd guess that we are a big reason why they no longer exist.
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It's also recently been suggested by a study saying that about 1-4% of our DNA is Homo neanderthalensis - so even had THEY been the dominant species it's likely that 1-4% of their DNA today would be Homo Sapien.
Either way you slice it, any of the intelligent species on Earth appear to have a common ancestor. So whether we killed off other intelligent forms of life and thats why there aren't any is moot: none of the other animal kingdoms have shown anything along the scale that humans have, or else we'd be c
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You are correct. That would be a rash assumption.
However, the qualities of this planet that make it suitable for life aren't as simple as "well, look at it!"
The entire planet has gone through several phases of development (molten, crusty, wet, snowball, volcanic, tropical, tectonic, plus some not-so-planet-killer asteroid impacts) to shape what is now its ecology, and it's not showing any signs of being static yet.
So it would be egregiously inept, given this knowledge, to assume that other planets with sap
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Except of course the simple fact that perhaps they are just like us, and are too timid to leave their own solar system?
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We're not even building decent space stations. To me the priorities should be to build a space station that humans can live on "indefinitely". Not waste money on going to Mars.
When you have developed space stations on which people can live on indefinitely, you don't have to rush to Mars. In fact Mars becomes a lot less important economically. The asteroids would be more interesting- build space colonies from the asteroids. From that point you would b
at the core (Score:2)
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Make microwave popcorn without a microwave oven?
Define Haitable (Score:2)
Habitable seems to be in the eye of the beholder. Does it mean if we dropped off a human on the surface, he would be able to breathe? Does it mean that it is roughly the right mass? The right mass and roughly the right temperature? Right mass, temperature and has an atmosphere? All the above and has bountiful liquid water?
I am very excited about our discoveries over the past decade or so. But it will be another before we can truly have a reasonable idea of how many planets are "habitable".
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I assume that in this case, "habitable" means that it's within our technological means to survive there.
Getting there, on the other hand, is another matter entirely.
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Well, a surface that doesn't immediately kill us while we wear minimal life support apparatus would be a good start. Even if we can't breath the air, being able to wear regular clothing and no bulky gloves would be a big step up.
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Or even better, someplace that a genetically altered human could live?
... For various quantities of habitable (Score:2)
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My personal favorite example of such claims has always been "baked with real vegetables" on some snack crackers.
In no way does that imply that the vegetables are ingredients. Merely that they were b
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The sentence is always true as the operative advertising word is "could".
Teh maths (Score:5, Funny)
But using some statistics,
Uh oh...
How many sagans is that? (Score:3, Funny)
...there may be billions of potentially habitable worlds in the galaxy.
How many sagans is that?
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5x10^-1sagans.
sudo mod me funny
Let's cut to the chase (Score:2)
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They'd turn you down too. Sorry.
If there are really billions of such planets ... (Score:2)
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Billions of Linuses (Score:2)
Trillions of Beowulf clusters ...
What a godawful headline... (Score:5, Insightful)
The Galaxy May Have Billions of Habitable Planets
Or, you know, less than that.
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Ahh but see, they are simply narrowing things down to an upper bound. So now we can say there are between 1 and X billions of habitable planets out there!
How big they are is only a portion of the equation (Score:5, Insightful)
uhh... Cosmos anyone? (Score:2)
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Our children's children's children won't know, really (unless we find a copy of the Hitchhiker's Guide to the Galaxy lying around). But the statistical estimate will continue to improve.
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1% accuracy?
This isn't even a single-order-of-magnitude accuracy guess.
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I was going to put that in there, but I figured I would let someone else be the smart arse
Anyone else see something wrong with this? (Score:2)
...they cannot detect planets smaller than 3 times the Earth’s mass.
...they can estimate from the trend that as many as 25% of sun-like stars have earth-mass planets orbiting them!
So they're inferring based on the planets that they haven't detected...
Billions? (Score:2)
If the universe is really infinite*, and if there is any nonzero percentage of planets which are habitable*, then there are infinitely many habitable planets by logical conclusion.
Until or unless we find one, and one that’s close enough to actually learn something useful from it... what difference does it make how many of them are theoretically out there?
*unproven/unknown
Pointless (Score:2)
Billions and Billions (Score:2)
This has been "known" for a long time. If I remember correctly, that's what Carl Sagan was talking about with his "billions and billions."
Paging Carl Sagan... (Score:3, Insightful)
Shouldn't that be "billions and billions"?
I bet when we do find life it will not be exciting (Score:2)
Let me see if I'm following the math here... (Score:5, Insightful)
You take a number which you don't know very well, so you estimate it. Then multiply it by a factor which you really don't know, so you just guess that. Next you multiply the result by another number which you may never know, so you just pull that one out of /dev/random, and multiply them all together.
And wow, you get a result that you like! That's amazing!
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epic hot damn (Score:2)
Habitability requires a Jupiter (Score:3, Insightful)
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P.S.: Carl Sagan says "High !".
It seems appropriate to hear from Zombie Sagan on Halloween weekend. Let's raise a bowl and toast his accomplishments.
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