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Space Science

Milky Way Stuffed With an Estimated 50 Billion Alien Worlds 331

Posted by Soulskill from the not-to-mention-nougat dept.
astroengine writes "Using data extrapolated from the early Kepler observations of 1,235 candidate exoplanets, mission scientists have placed an estimate on the number of alien worlds there are in our galaxy. There are thought to be 50 billion exoplanets, 500 million of which are probably orbiting within their stars' habitable zones."
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Milky Way Stuffed With an Estimated 50 Billion Alien Worlds More

Milky Way Stuffed With an Estimated 50 Billion Alien Worlds

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  • There's no intelligent life close by (Score:5, Funny)

    by davidwr ( 791652 ) on Sunday February 20, 2011 @03:44AM (#35258290) Homepage Journal

    Any truly intelligent life would've detected us and fled to another galaxy long ago.

    • Re: (Score:2)

      by Bruha ( 412869 )

      There probably is, but apparently none of them have either invented FTL travel, or they have some prime directive crap going on. Then again ancient aliens is a pretty good show, makes you wonder if they really walked among us, why did they leave and never came back.

      • Re: (Score:2)

        by pakar ( 813627 )

        Ehm... "again ancient aliens" and "good show" in the same sentence... Don't get me started on all the factual errors in that show.... But it's always fun to watch for a BIG laugh..

        • I've not seen Ancient Aliens in the UK, but we have a show called "Most Haunted" here where they visit so called, haunted places, and it pretty much sounds like the same thing, any noise, anything slightly strange that can't instantly be explained is labelled as a ghost.

    • Any truly intelligent life would've detected us and fled

      The tragic truth may take on a couple of possible forms:

      - Intelligent life forms typically evolve to be just like us. The conditions favoring life and evolution in all likelihood culminates in intelligent primates. Out of the chaos of the second law of thermodynamics, societies of intelligentsia will wind up with all our shortcomings. We can't trust them, and they can't trust us. Hell, we can't trust us.

      - When we finally get face time with alien intel

  • Since there are between 200 and 400 billion stars [wikipedia.org] in the Milky Way that amounts to between 0.25 and 0.125 planets per star on average. Granted TFA states that there are at least this many, but I would have thought the number be much higher, considering the number of planets in our own solar system.

    • Re: (Score:3, Interesting)

      by Anonymous Coward

      Having planet formation at all is the statistically meaningful event. Getting one or nine as the terminal result is just a matter of the initial distribution of the cloud.

      And 500 million in the habitable zone is only 5*10^8, which is a really small number to be plugging into a modified Drake equation unless the likelihood of life occurring and continuing to exist is overwhelmingly high and unless the probability of life developing intelligence is similarly high. If each term is 1% (by many estimates, an ext

    • Re:Only 50 billion? (Score:5, Informative)

      by jgoemat ( 565882 ) on Sunday February 20, 2011 @04:54AM (#35258478)
      Kepler is only looking at Sun-like stars, which only account for 13% of the stars in our galaxy. Also the mission has only been going on for two years and they need at least two transits to say they might have found a planet, so this wouldn't count planets much further away from their star than Earth is from Sol.

  • My experience (Score:5, Funny)

    by Sarten-X ( 1102295 ) on Sunday February 20, 2011 @03:46AM (#35258296) Homepage
    Based on my time in high school, I expect those 500 million habitable planets are all inviting each other to parties, picking each other for teams, and definitely getting laid. Earth is getting left out, and nobody has the heart to tell us.

    • Based on my time in high school, I expect those 500 million habitable planets are all inviting each other to parties, picking each other for teams, and definitely getting laid. Earth is getting left out, and nobody has the heart to tell us.

      I think we should pass on getting laid for the time being thanks.

  • Using the figures here I come up with 78 million in our galaxy: Kepler found 5 Earth sized planets in the habitable zone. They searched 156000 Sun-like stars. 13% of the stars in our galaxy are sun-like. There are 100 billion stars in our galaxy. Kepler would only find Earth if the axis of rotation of the system was within about 1/2 degree of the viewing angle. The relative angles are random. Sorry I only came up with 78 million, but if you take into account that there are 100 billion galaxies in th

    • So where are the aliens? With this many planets available we should be able to hear or see a few alien civilisations by now. Something is wrong with the assumption that aliens will "grow up like us". I don't think it will happen as often as we assume.

      • Re: (Score:2)

        by Arlet ( 29997 )

        It's not that easy. Radio/TV transmissions leaking into space are very weak. There could be an alien civilization at 10 light years from us, and we could aim our arecibo dish straight at them, without picking up anything. Our only hope is that they'll point a very powerful transmitter straight in our direction, at exactly the same time as we point our most sensitive receiver in their direction. The chances of this happening are astronomically small.

        And of course, most suitable alien planets are much further

        • Re: (Score:3)

          by h4rm0ny ( 722443 )
          Not only that, but there are two further qualifiers: One is that possibly radio-waves aren't the best way of communicating. Maybe there's some fancy quantum-entanglement doo-dad that we're right around the corner from discovering and which civilisations almost always progress to once they pass radio waves. Granted, it seems unlikely to us, but how would we know from where we are. Second idea is that sufficiently advanced civilisations tend not to waste power by needlessly broadcasting massive amounts of rad

          • Perhaps the thing to look for is some kind of spectral data? That might at least tell us if there's life (similar to ours). I'm not sure what the tell-tale lines for civilization are though.

      • It could be that we are the first to reach the level of spaceflight. It could also be that we are the first to reach any level of civilization.

        • It could be, but it would be weird if it were the case. Out of millions we are first? Ok someone has to be first but its still kind of improbable.

          Of course our ability to spot the radio transmissions from other worlds is pretty thin still so we may well have missed some, infact it seems likely.

      • Where are the aliens? Simple (Score:5, Insightful)

        by SmallFurryCreature ( 593017 ) on Sunday February 20, 2011 @07:28AM (#35258942) Journal

        Lost in time. Lets say all those 500 million planets are earth like. That means they got a lifespan of a mere 10 billion years (earth is 4.5 billion old and got about 5 billion years left). On this planet (as far as we know) there has been one species influential enough to possibly be noticed in space or indeed notice space itself. For a grant total of just over a hundred years. In 10 billion. We have no way of knowing how long civilizations such as ours manage to survive. But even if you make it a thousand years, it still the shortest of blips on the time line of our planet.

        Even if you account for that the fact that our planet wasn't always habitable during its life, it is still a VERY wide window in which to look. We could look at every single habitable planet and just never ever be looking at the right time to see life.

        Every single planet could spawn life within its own lifespan and we still would never ever know about it. There are places in our own solar system that have possibly supported life and some still might, and we don't know for certain (yet) because we can't look for it yet.

        I can not see a dinosaur, nor a dodo or an elephant bird or countless other forms of lifes which we know to have excisted, merely because time gets in the way. Space got far more time. We are not alone, just lost in a sea of time.

      • Re: (Score:2)

        by rossdee ( 243626 )

        Maybe many of those worls have simple forms of life, like this planet had handreds of million years ago, but haven't evolved into more complex forms yet. It took a long time for intelligent tool users to evolve here on earth, and we have only had radio transmissions for a bit more than a century. The aliens could have started to explore space, found it too expensive, and gave it up. Maybe they had a religious conversion, and gave up nearly all technology (except fireplaces)

        Who knows

      • Re: (Score:3)

        by jbolden ( 176878 )

        Why should be able to see and hear them? Are we sure we would even identify them if we did? Will it only be clear in retrospect? We just ran into a tribe living in the Amazon that hadn't been contacted. They saw airplanes, regularly and just associated them with the environment. They had sightings of cruise ships and military ships but since there was no such thing as a boat that big .... they didn't make anything of it.

      • Re:78 million (Score:5, Insightful)

        by Jason Levine ( 196982 ) on Sunday February 20, 2011 @09:35AM (#35259370) Homepage

        The two big problems are time and distance. For us to detect an alien civilization, they've had to have developed radio techology. They also need to have not progressed beyond radio. We're already moving to cabled systems instead of radio broadcasts. To an alien civilization trying to detect us, we'd be getting fainter and fainter. So there's a short window of time in which we could detect alien broadcasts.

        In addition, space is big. (Insert Hitchhiker's Guide To The Galaxy quote here.) If an alien civilization is 10,000 light years away from us and developed radio technology 5,000 years ago, we wouldn't detect their broadcasts for another 5,000 years. The radio waves would have a huge amount of space to cover before reaching us.

        Finally, considering time on our side, we've only been listening for a short period of time. If that hypothetical alien civilization 10,000 light years away developed radio technology 12,000 years ago and moved past the technology 11,000 years ago, the last alien broadcasts would have moved past the Earth in the early 1900's. They would have swept right past us without us knowing at all.

  • For all it even matters . . . (Score:5, Insightful)

    by Seumas ( 6865 ) on Sunday February 20, 2011 @03:52AM (#35258318)

    My mother was barely a high school girl when we landed on the moon and since the last time we stepped foot on something other than the earth, she had children who grew to be old enough to have children who were as old as she was, then. We keep cutting budgets, because "we don't need all that there space sci-fi mumbo-jumbo when they can't even fix the potholes in front of mah damn house durr durr durr!". We talk about grand attempts to Mars, which we then never fund or push forward after having fancy press conferences about it. Then we do the same with plans to . . . go back to the moon.

    I suppose an optimistic way to look at it is that while we may see no advances in exploration in the near future, we do continue to increase technology which will in turn make future exploration even more successful. Sort of the way you could set a computer to cracking an encryption today that could do it in a few hours, while if you had started cracking that encryption in 1980 and let that computer keep running, it still wouldn't have completed the calculations, today. Still, that doesn't put one at ease over the general lack of ambition. Not to mention the amount that the last major space effort contributed to the technological advances that we have today and are now counting on continuing to advance at a rate so as to re-jumpstart the space exploration.

    I think it's safe to resign ourselves to little more happening in our lives. Our best hope is that while the likes of Carmack are building low orbit space planes and the likes of Richard Branson are building low orbit space hotels (which, let's recognize, are going to be nothing more than crammed little pods for decades to come), they somehow stumble into a viable commercial reason to explore some space out there. Otherwise, we're generations away from much more than sending RC cars to the surface of Mars, again.

    • You need not worry about our temporary stall in space exploration. Once Starbuck's, McDonald's, AT&T and Comcast figure out how to make money from it, we'll have manned stations on every rock between here and the edge of the universe.

      • You need not worry about our temporary stall in space exploration. Once Starbuck's, McDonald's, AT&T and Comcast figure out how to make money from it, we'll have manned stations on every rock between here and the edge of the universe.

        I think you're confusing Starbucks/McDonald's/AT&T/Comcast with the Hudson Bay Company. Very different business models. HBC, "Here Before Christ" :)

    • I think the era of humans living in space (exploring space is a mere idle pastime if all you're going to do is to snap blurred photos or vicariously poke some pebble in some distant landscape) will turn out pretty much like the fabled Year of Linux on the Desktop. There won't be a year of Linux on the desktop. We're just going to find out one day we are using Linux on the desktop. Or we won't (because by that time we'll all be using wallpaper or holographically projected computers).

      Right now all we have is

    • Not trying to be too ideological here, but what you might hope for is that these early space tourism efforts become profitable. What we saw with Apollo and the cold war was the government putting a whole load of money into sending Air Force pilots to the moon, and it worked, and it was a great achievement. But once the political goals were reached, the program somewhat stalled. If we had a profitable and lively space tourism economy, perhaps the private sector would get the snowball rolling, and we'd be tal

    • I doubt that the entities we send to the stars would, today, even count as human - or have any sort of rights. However, those people/things will be able to prove a direct link to us - even if it's because we made them, rather than gave birth to them.

      Humans are not designed for space travel. We don't live long enough. We're too fragile, need too much energy just to stay alive and can't eat electricity. Whether we overcome those design "mistakes" in biological or mechanical solutions will be an interesting

    • Re: (Score:2)

      by jbolden ( 176878 )

      From 1930 to the present has been a golden age for astronomy / cosmology. We've discovered a lot since the 1970s. It turns out that manned flight is not a particularly useful way to learn about space. We don't have the technology to do anything useful with men in space yet. Wishing doesn't make it so. One of the things we've learned is how hostile and dangerous space is, its a tougher environment to survive in than we ever imagined.

      Now you want to do a good warmup, long term bases under the ocean which

      • I think the fear is that we will descend into a dark age (or even be obliterated entirely) before we can put that knowledge to use.

        By way of explanation... with folks living in viable, self-contained colonies on the Moon, Mars, or in Bernal/O'Neill stations, we can at least have the ultimate backup for human knowledge (and humanity itself). This way, if things go to shit here on Earth, at least some people will still be pushing the boundaries of knowledge (or in some scenarios, still be alive in a not-as-ho

  • In a universe with as many stars and planets as ours, Earth couldn't possibly be the only planet whose orbit just happened to be in the right place to sustain life.

    • Comment removed (Score:4, Insightful)

      by account_deleted ( 4530225 ) on Sunday February 20, 2011 @04:16AM (#35258398)
      Comment removed based on user account deletion

      • Re: (Score:3, Insightful)

        by jcwayne ( 995747 )

        In practical terms that's not really meaningful. Considering the timescale involved, you're probably dealing with a margin of error of +/- 1 billion years. Then consider that the speed of evolution, in all its forms (i.e. planetary, geological, biological, societal, and technological), is influenced by an incalculable number of interrelated factors. So, in reality, being "one of the first" could mean that we're several billion years behind some and ahead of others.

    • In a universe with as many stars and planets as ours, Earth couldn't possibly be the only planet whose orbit just happened to be in the right place to sustain life.

      Given that we only know of one planet that contains life, you can't possibly draw the conclusion (that aliens are statistically likely to exist). You're assuming the only requirement is that a planet be in a star's habitable zone - but you have nothing to base that assumption on.

      You can't extrapolate a line from one point.

      • Re: (Score:2)

        by AGMW ( 594303 )

        You can't extrapolate a line from one point.

        Well, that's not true. And best of all you can chose which direction to extrapolate it! Obviously, this extrapolation then says more about the extrapolator than the data, but it can still be an interesting experiment.

      • Re: (Score:2)

        by jgoemat ( 565882 )

        Given that we only know of one planet that contains life, you can't possibly draw the conclusion (that aliens are statistically likely to exist). You're assuming the only requirement is that a planet be in a star's habitable zone - but you have nothing to base that assumption on.

        You can't extrapolate a line from one point.

        From what we know, liquid water is required to sustain life. For observational purposes we have a sample size of (1) planet which resides in the habitable zone for life to exist, and that one planet contains life. The sample size is small, but it is at least as good a bet that life exists on one of the millions of other planets in the same situation as ours that exist in our galaxy as it is to bet against it.

        The oldest undisputed evidence for bacterial life on Earth is 3 billion years ago, but other ev

  • Wow, 50 billion?
    That candy bar must have a lot of calories...

  • We're gonna need more than that.. population growth. If when we die, we get our own planet, we're gonna run out!

    • This got me thinking that perhaps we should aim a few containers with microbial life at some nearby "Earth-candidates". That way we can at least ensure that something from here lives on, somewhere. (Hope there isn't already something there, that could mess up their ecosystem, hehe)

      • Re: (Score:2)

        by amorsen ( 7485 )

        We cannot really send containers anywhere useful except Mars, Venus, and Europa. Neither of those are particularly good hopes for sustaining intelligent life one day. Except Venus perhaps, but that is going to take more than some microbes.

        • I don't see why not? Surely we could develop a delivery method that can take its time to get to nearby star systems?

          • Re: (Score:2)

            by amorsen ( 7485 )

            In theory we can develop anything. In practice, we are far off from being able to send anything to even the nearest stars with a travel time shorter than thousands of years. It is unlikely that we can make anything which can last thousands of years and still be functional enough to find a planet and brake to a reasonable speed before landing.

      • Yeah, just like that other nearby civilisation did before they were wiped out.

  • I'm dusting off my suitcases right now.

    NOT.

    I really didn't need to know this. It's way too big an always-out-of-reach carrot for a guy who's always thought the pasture he couldn't see must surely be greener.

    • I really didn't need to know this. It's way too big an always-out-of-reach carrot for a guy who's always thought the pasture he couldn't see must surely be greener.

      Be careful - that pasture may BE greener, but that green might also be a toxic slime mold.

  • Its a nice round number. See? God did that.

  • Yes, because as a Scientist I always trust an extrapolation that goes from 1000 to 500 million. On our Earth I believe these people normally peddle Homeopathy.

    • Opinion polls do that fairly often with public opinion (around 1,500 samples, tops, extrapolating to 300 million), and usually end up off by no more than a few percent.
  • 500 million worlds within habitable zones sounds like a lot, but with ~300 billion stars in the galaxy those are spread fairly thin. And certainly not all of those planets are "habitable"...

  • Sorry... but this is not impressive to me.

    Half a billion other planets that could potentially be habitable means approximately zilch to me because it would take so long to travel there that the spaceship that takes off would have to be capable of supporting multiple generations of humans, and there's a not altogether insignificant chance that the generations that arrive will not remember or care why they are even on that ship. What happens if a whole generation of people don't even want to be on that mi

    • I would think they wouldn't have much of a choice. They'd be beyond the point of returning to Earth. Their only other option would be to alter course such that they wouldn't have a firm destination at all.

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