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Space Earth Science

Finding Twin Earths Is Harder Than We Thought 161

Matt_dk writes "Does a twin Earth exist somewhere in our galaxy? Astronomers are getting closer and closer to finding an Earth-sized planet in an Earth-like orbit. NASA's Kepler spacecraft just launched to find such worlds. Once the search succeeds, the next questions driving research will be: Is that planet habitable? Does it have an Earth-like atmosphere? Answering those questions will not be easy. 'We'll have to be really lucky to decipher an Earth-like planet's atmosphere during a transit event so that we can tell it is Earth-like,' said Kaltenegger. 'We will need to add up many transits to do so — hundreds of them, even for stars as close as 20 light-years away.'" The abstract of their paper offers a link to the complete paper as a 17-page PDF; here is a short description from 2007 of the same researchers' work, outlining the type of spectral signature that an Earth-like atmosphere would be expected to show.
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Finding Twin Earths Is Harder Than We Thought

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  • Solution: (Score:3, Funny)

    by Anonymous Coward on Sunday March 22, 2009 @02:16AM (#27286047)
    Build in a FTL drive and have Starbuck magically... oh fuck it.. what a cop out. :\
  • by Jane Q. Public ( 1010737 ) on Sunday March 22, 2009 @02:24AM (#27286077)
    that it will take hundreds of years to tell if they are truly Earth-like. And that is complete nonsense.

    Once we find a sufficient collection of candidate planets using this instrument, we can devise a different device/experiment to narrow down whether they are Earth-like. That should take maybe a few years to ten years.

    That is more-or-less the pattern we have been following, and it has been successful so far. I see no reason to change.
    • Clarification (Score:3, Insightful)

      I mean a few to ten years to build the device; a few to ten years to operate it. That is still vastly better than hundreds.
    • by Vectronic ( 1221470 ) on Sunday March 22, 2009 @03:38AM (#27286311)

      "...and it has been successful so far. I see no reason to change."

      Has it? Can we really be sure that the current method is accurate in ruling out earth-like and non-earth-like?

      I'm not really disagreeing with you, just not so sure that it's 100% accurate (which is ideal, but not exactly realistic). To me this sounds like they are intentionally thwarting the idea, so the public will go "well shit, guess we're trapped here for 300 more years" kinda thing.

      Current method seems fine, applied to the new equipment. Keep searching, monitor the ones we already assume are earth-like, and when we figure out a way to do something about it (wormholes, etc) we pick the best candidate at that time, and go for it, if that fails, or if it takes longer than the time to build/induce/etc the next method of travel/communication, we head for the second candidate, etc... this "new" method seem to suppose that we won't be able to do anything about it for 200 more years, so we have the time to piss around with hundreds of tests, when we should probably assume it'l be possible next year, kinda like "Year of Linux on the Desktop", may never happen, but why can't it happen next year? Just because you may not succeed, doesn't mean you should't try.

      • by radtea ( 464814 )

        just not so sure that it's 100% accurate( which is ideal, but not exactly realistic)

        "100% accurate" is not the ideal because things that exist are better than things that are not, and no test that exists will ever be 100% accurate, so there will always be a better test: the one that actually exists!

        It would be silly to have a test that was "better than ideal", so obviously the ideal test is the best one we can actually build, not the best one we can imagine. Our imagination is not the arbiter of quality.

    • Re: (Score:3, Interesting)

      by TapeCutter ( 624760 ) *
      I was 10 when I watched Armstrong land on the moon, every kid was into space and I had read "grown up books" in the library with pictures of water canals on Mars and rainforests on Venus. Since then astronomy has been fully digitised and we have mapped most of the EM spectrum []. I'm not saying it won't continue to improve (especially in the area of corrective optics) but I think it will be slower now that the spectrum land rush is coming to an end and digitization is well and trully complete.

      The long term
    • by Nyeerrmm ( 940927 ) on Sunday March 22, 2009 @04:37AM (#27286501)

      From what I can tell in a brief skim, it really does pose a fundamental limit given current technology. The problem is that with the largest mirror we can imagine getting up into space, and with the highest sensitivity sensors, the signal-to-noise ratio is still too low to get a usable measurement without taking hundreds of measurements.

      They plan to detect the chemicals in the atmosphere by measuring the absorption bands in the starlight as some of it passes through the atmosphere. This is presumably going to be a lot more sensitive than trying to detect the light from the planet directly, since you have a lot more photons to carry the information. The signal to noise ratio in this case is really limited by the unfortunate fact that light energy is discretized and you can't make finer measurements than a single photon. Thus a large mirror with a high-quantum efficiency (95%) sensor, is really the best you can do.

      The only hope to improve this is to either get bigger mirrors, which really depends on improving space access and is unlikely to give order of magnitude improvements, or to implement an as yet unrealized method that is able to get more information. If it were a problem of angular resolution there are plenty of interesting tricks you could use to improve it. Unfortunately I can't think of anything better, and it doesn't seem anyone else has yet either. Of course, that doesn't mean no one will... but its not as simple as just designing the next mission.

      Actually... random 3:30 am idea... if you did something in thermal-IR, and measured the absorption of the blackbody emissions of the planet by the atmosphere you might be able to get something working. The intensity would be a lot lower than looking at the stars light, but the dimming due to absorption would be much larger percentage-wise... although it would take some heavy math to show if it would actually give you a better SNR. Of course, there are plenty of holes here: among other things, my knowledge of atmospheric chemistry and absorption is very limited, and this would all depend on being able to resolve the star separate from the planet, and would thus rely on some complicated interferometric methods....... and you'd have to block out the star light to be able to get the planet light as anything more than noise... and probably the number of photons in thermal IR from a planet are too low to be able to even see it on its own... but maybe I'm wrong and it could work, or something else can.

      • already proposing theoretical limits, that in fact are not so. This is exactly to what I was referring.

        If there are limits to the tech of certain ways to find out things, we will just change the tech... or find a different way.

        For example: one well-known way to overcome the limits of mirror size is to use multiple mirrors, spaced a good distance apart. We already use this technique in other areas of astronomy. It allows better resolution than the sum of the individual mirrors would indicate... almost
        • Using multiple mirrors is great for increasing your angular resolution, I know, its what my graduate thesis is about. Unfortunately, it's not nearly as good at increasing your light gathering capability. 6.5 meters is the size of the JWST, so if you wanted to improve your SNR by a factor of 10, you'd have to have 10 JWST's, and funding that is just not going to happen at this point, not without a drastic drop in cost of access to space.

          The gravitational lensing concept that others suggested is valuable be

          • I understand. But what I am trying to point out is that everybody is describing these limits in regard to today's technology. Now, that is not unreasonable, since tomorrow's technology is largely un-guessable. So while my belief might come down to something approaching "faith", I still believe that in 10 or 20 years we will have technology to make this determination in less than 2 or 3 hundred years. After all, the idea that we would even be detecting earth-sized planets was beyond the practical technology
            • Yes, its possible, but the way it will be possible is through drastic reduction in launch costs that can get you far more aperture or the ability to get a JWST sized scope out to a 500 AU orbit for gravitational lensing. I have a lot of hope for that, I'm involved with organizations working to make it happen.

              However, there really is no way to develop a new instrument capable of doing so without incredible infrastructure or discovering a brand new kind of physics that allows it. The developments of the pas

    • Re: (Score:3, Insightful)

      by MrKaos ( 858439 )

      we can devise a different device/experiment to narrow down whether they are Earth-like

      I don't know if this is valid but, what about 10 devices doing the same job?

      • by Mal-2 ( 675116 )

        Better yet, 10 devices working 10 different targets. When one is found that is particularly interesting, the other nine drop what they're doing and chip in.


    • Re: (Score:3, Interesting)

      by Z00L00K ( 682162 )

      Just because it's hard doesn't mean that we shall give up trying.

      This field is still a very young field, and the methods used to find planets will be more and more refined over time.

      But it's also important to not count out stellar systems that may not look like they are going to contain earth-like planets. Even a negative answer is an answer giving usable data in this case.

      Earth is the only speck of dust in the universe where we are certain that there is life. If it's intelligent enough to prosper in the lo

    • by forand ( 530402 ) on Sunday March 22, 2009 @10:29AM (#27287729) Homepage
      IAAP (I am an astro-physicist) and while I would love to agree with you, I cannot. The problem is not that we do not know how to get a quick measurement the problem is that is would take huge sums of money as well as very significant technological improvements.

      Science is being limited much more by funding and physical constraints. Current ground based telescopes are operating very near the quantum limit and space based observatories are expensive to the point of making them infeasible.

      All in all I think that pointing a few telescopes at a given object for long periods of time for a total cost far exceeding that of building a better solution is the path that is being (and will continue to be) pushed on the scientific community. The prices tags for what we want to know are so large and budgets tend to be sabotaged by political agendas as to make it appear that we are incapable of doing science for a reasonable price.
      • even you are stating limits in terms of TODAY. Today's tech might limit our ability to discern earthlike planets to 2 or 3 hundred years... but in 20 years, will our technology still be so limited? You are second-guessing the future in a way that history suggests is incorrect.

        Not much more than 20 years ago, the very idea of trying to find earthlike planets telescopically would likely have been laughed at.
      • by yusing ( 216625 )

        I am half-astrophysicist. I sympathize with your need for much more money for what you want to know, I am the same way with sex - very very curious and a deep need to know.

        I guess I need to point out that most Americans also need much more money. Not to (ever) mention the rest of the world.

        And so your dream is not likely to be realized by wanting much, much more money. So, like me, you'll have to find clever ways to accomplish your need to know that don't require much, much more money - using your imaginati

  • If they're at a similar point in the evolution of intelligence, that's kinda scary in a way. Maybe they've already made the jump to a pervasive machine intelligence; that would probably be less distressing.
    • Wow! (Score:3, Interesting)

      Two huge issues in as many sentences.

      There is no logical reason to assume similar development, barring further evidence. That could be a good or bad thing.

      But your second sentence... wow! Where do you get off making an assumption like that? First, if they have anything like "a pervasive machine intelligence", then their technical development would be VASTLY beyond ours. We are not even remotely close to anything like that.

      Second, even if they did, how in the world do you conclude that would be "les
      • Second, even if they did, how in the world do you conclude that would be "less distressing"??

        This is Slashdot, and you're wondering how someone decided that a machine would be easier to deal with than a living creature. Hmm...

        • You probably meant your reply in jest (understandably so, considering the stigma of underdeveloped social skills that Slashdotters are famously afflicted with), but I'll reply anyhow :).

          I love people. I'm what you might call a highly social nerd, someone who really enjoys the company of others in a variety of social contexts. Yeah, I also enjoy sequestering myself in my home office and writing code for a couple of days at a time, but there comes a point where human contact is critical for me. I have frie
          • I did indeed mean it in jest. And to be honest, most of the nerds I know have more diverse social lives than the non-nerds, though their activities may not be the popular idea of fun. That just makes them more interesting to be around, IMO.

      • Re: (Score:3, Interesting)

        First, if they have anything like "a pervasive machine intelligence", then their technical development would be VASTLY beyond ours. We are not even remotely close to anything like that.

        In my view, I have good reason to believe we're much closer to that than most people would like to accept. Many reasons, actually. It's probably a normal side effect of human vanity that we take comfort in our present position at the top of the intelligence curve, but I think it's an inescapable fact that future historians (in whatever form they might take) will describe humanity as a species that was destined to outdo itself. To me, what occurs after that will be the most interesting chapter in the history

        • Sorry, but I am a software engineer who has followed the field of AI since childhood, and I have a great many reasons to disagree. The field of actual AI has gone almost nowhere in the last 30 years. Yes, machines have been made to SEEM more "intelligent" in many ways, but that is not the same thing at all.

          If you are referring to anything like human-level intelligence, machines are just about as stupid as they were in the 1960s. More hardware and software (and therefore more sophistication) can fit in a
          • My level of experience seems to closely mirror yours, and I have to respectfully disagree again. I do need to clarify a point: I'm not making any claim that traditional AI approaches have made any great strides in replicating a humanistic artificial intelligence. My point is that as we continue to see systems that are made up of increasingly dense and interconnected computing units (whether in a single lab or on a global scale), we're coming close to the point where computing systems need virtually no human
      • Re:Wow! (Score:4, Interesting)

        by Jurily ( 900488 ) <<moc.liamg> <ta> <yliruj>> on Sunday March 22, 2009 @04:40AM (#27286507)

        Second, even if they did, how in the world do you conclude that would be "less distressing"?? One does not follow from the other.

        Well, duh. If they have advanced AI, they probably have internet as well. Which means we can view alien porn while we're being wiped out.

      • First, if they have anything like "a pervasive machine intelligence", then their technical development would be VASTLY beyond ours. We are not even remotely close to anything like that.

        When you take into account the speed up of technology, and the way we are able to build off the previous generation of technology to help us with creating the new version, you might realise that we are probably not nearly as far out as you think(perhaps that should be "as you hope"). From the lowest estimates from the likes of Kurzweil at about 10-20 years to the highest estimates of slightly less optimistic thinkers at only about a hundred years, it is likely to come fairly soon.

        • Please pass on to me ONE major advance that has been made in the field of Artificial Intelligence in the past 30 years. Just one. I would be interested in knowing about it, because I have been following this field closely and so far I have not.
          • Please tell me ONE major advance in whatever field you work in.

            It doesn't really work like that. Very rarely in science is there some major advance that you can specifically point to. Everything we had back then in AI we still have, but it is so much better. The neuroscience side of things is progressing, we are getting better data about the brain. Developing practical applications [] based on that. Voice recognition is pretty good now, automatic translation is better, computational vision is better, autonomo

            • Sure, they're all getting better. As I pointed out elsewhere, more hardware and more software can fit in a much smaller space today, allowing us the sheer computational power to make many devices much more sophisticated than they were before. And our techniques have improved, and so on. Incrementally.

              In my opinion, voice recognition and language translation are irrelevancies. They make input and output somewhat easier, no more. I do not believe they are essential characteristics for intelligence.

              And I
              • I guess it depends what you mean then. To me artificial intelligence doesn't necessarily have to be exactly the same type of intelligence as a human, that's practically impossible, because it would have to have all the same type of sensory data as a human, which means robotics, or at least human->machine interfacing, has to come along massively. But an intelligence capable of solving most of the same problems as humans can, within its own domain (whether that be an artificial 3D world or a world of numer
    • I'm fairly certain that the little green men, ticked off after years of being depicted as scrawny, bug-eyed, space-faring bobbleheads, will just come in rayguns blazing, but the machines, prizing efficiency and precision above our human failings, would probably arrive and play muzak with a pre-recorded voiceover telling us that our death is important, and would we please wait.

      Is being blasted into your component molecules by unimaginably powerful energy beams really more distressing than being put on hold?

      • Why anyone would think that an advanced machine intelligence would need to compete with human beings for resources is beyond me. After all, if you're essentially dealing with the mind of God on Earth, I'm fairly certain that such an entity would tend toward an exponentially increasing rate of efficiency per computing unit. This implies exponentially diminishing reliance upon external energy inputs. It also puts the human race in an interesting position: one has to wonder if this will be the tipping point wh
        • This implies exponentially diminishing reliance upon external energy inputs.

          Nonesense. Even if computational efficiency approaches infinity - which is pie in the sky anyway - other actions like moving around, extracting raw materials and producing useful things from them are still bound by the laws of thermodynamics.

          P.S. exponential isn't a fancy word for "a lot".

          • Computational efficiency approaching infinity is pie in the sky only as long as humans have a hand in controlling the process.

            As for your notes on the work "exponential," wow, you don't say. You must some kind of college degree or something.
        • Why anyone would think that an advanced machine intelligence would need to compete with human beings for resources is beyond me.

          Me too, since I wrote nothing about competing for resources.

          What I did suggest was that machines would prize precision and efficiency; by that measure we barely qualify as an intelligent species. Individuals may be precise and efficient, but as a group we aren't, and a single machine intelligence with many nodes looking for intelligence that resembles itself may not even realise th

          • What I did suggest was that machines would prize precision and efficiency; by that measure we barely qualify as an intelligent species

            You've absolutley no idea what an alien machine might prize so deciding it would be precision and efficiency is an enourmous assumption. Even if it was true I've no idea how a species can be said to be precise, I think thats pretty much meaningless but as for efficiency I think any alien observer would conclude that humans are in fact very efficient in the way they interact a

      • ... the little green men...

        Back in the 1960's Captain Kirk couldn't swing a dead cat around his head without hitting a "Class 'M'" planet every week. Can't NASA lure him back out of retirement?

        . . . and his little green men were always platinum blond chicks: []

        I nominate "Shahna" as the official Slashdot mascot, because she is wears a tinfoil bikini . . . and she wields a giant can-opener.

        Now, where is my "rogue" source code? Does a giant can-opener do more damage than a two-handed

        • . . . and his little green men were always platinum blond chicks

          Maybe not men*, but some were definitely green [].

          *At least that we know of. I always had questions about why the young, naive Chekov was the navigator...

      • Bullets hurt people because of human blood circulation (loss of blood) and the size of our organs (heh). If robots were built differently or little green men evolved differently, bullets would most likely be ineffective. There is no reason that there is only one wire connecting processor to leg and opening one loop should not hurt the other parts of the circuit. Also, there is almost no reason why the processor needs to be 15 cm big, or the leg motor has to take up the whole length of the leg. There is

      • by Haoie ( 1277294 )

        That's fine.

        Our germs will take care of them, ha.

        Or computer viruses created on a 1995 laptop. For sure.

      • by Agripa ( 139780 )

        Or maybe our technology took a different road [].

        • I wouldn't rule that out, but it would have ruined the gag.

          Interesting link, BTW. I'll have to check that one out.

    • Maybe they've already made the jump to a pervasive machine intelligence...

      They've had Conficker-gate too?

  • Wrong Approach? (Score:3, Interesting)

    by vigmeister ( 1112659 ) on Sunday March 22, 2009 @02:27AM (#27286093)

    IANA Astronomer, but perhaps it may be prudent to start looking at the more obvious candidates in terms of how conducive they are to human habitation and evaluate them in terms of what it'll take to make that possible. If an alternate habitat for humans is a moderately serious concern, why bother looking at worlds whose characteristics are under heavy risk of changing by the time we get there? Have we even found a better candidate that one of Jupiter's moons or Mars?


    • Re:Wrong Approach? (Score:5, Informative)

      by Nyeerrmm ( 940927 ) on Sunday March 22, 2009 @03:40AM (#27286317)

      I don't think the idea is to find a new place for us to live. Obviously, our ability to take advantage of such a planet is incredibly limited.

      Rather, its to understand what the possibilities for life outside our planet are. Putting it in simplest terms, its working to get experimental data for some of the coefficients in the Drake equation.

      • In the near term, certainly.

        But imagine discovering a 1G +/- .2G planet, temp range -35C-40C, 75%N 25%O. Doesn't matter how far away; imagine finding one.

        I'd bet we'd start spooling up our manned spaceflight capability pretty darned quickly after that, and actual money would start being spent on solving the distance problem (propulsion techniques, suspended animation, longevity, generation ships...)

        When all that is "out west" is the edge of the earth, why bother? But as soon as the New World is discovered,

    • Re: (Score:3, Interesting)

      As it stands, we're never ever going to get there.

      For interstellar colonization you need either: 1. Artificial wombs and frozen sperm/eggs 2. Colossal generation ship (impractical and very depressing way to travel) 3. Cryogenic storage of humans 3. Self-reproducing sentient robots (humanity wouldn't be spread, but intelligent life would).

      And the ability for humanity to spend ass loads of money on something which they certainly won't see a return on in their lifetimes.

      • Re: (Score:3, Interesting)

        by gurps_npc ( 621217 )
        I call stupidity.

        You left out the answers of:

        4. Human lifespan expanded to over 1,000 years. Frankly, this is easier and more likely to do than #2 or #3.

        5. Many many set of short hops. Alpha Centauri is 4 light years away. An antimatter powered ship can reach 0.1 C. It only takes 40 years to get there. That is one generation, not multiple ones.

        6. FTL travel. Sorry, but no I don't fall for the "we don't know how to do it, so it must be impossible" stupidity that prevented people from trying

        • Re: (Score:3, Interesting)

          I'm afraid I call stupidity on you, sir.

          0.1 C as a peak velocity does not equal 40 years travel time to go 4 light years. Can you figure out why?

          Short hops would be a pretty stupid way to travel for the same reason.

          Additionally, antimatter is not a feasible fuel source given the immense cost, and the output (getting momentum out of hard gammas), and the storage difficulties. I'd like a source that shows antimatter can be contained using less energy then can actually be extracted from it - it's not clear tha

      • by jambox ( 1015589 )
        That's not actually true is it? Given time dilation, if there was a definite target then you could get there in a few years, subjective.
        • If you're traveling at a tiny fraction of c, time dilation is negligible.

          The point is that traveling at a tiny fraction of c is probably the best we can hope for.

          • by jambox ( 1015589 )
            For the foreseeable future yes. But there's no fundamental barrier to a suitably protected craft doing a fair chunk of c and getting a dilation factor of 2, making a 20 light year distant system reachable in 10 years.
  • 'We'll have to be really lucky to decipher an Earth-like planet's atmosphere during a transit event so that we can tell it is Earth-like,' said Kaltenegger.

    Governer Kaltenegger continued.... "It is not until this time that we can begin the search for Sarah Connor."

  • by DigiShaman ( 671371 ) on Sunday March 22, 2009 @02:41AM (#27286151) Homepage

    Let's just assume for a moment that a 2nd Earth was discovered with life an all. Would this be a turning point for actually dropping vast amounts of money in R&D for interstellar travel? Iâ(TM)m talking about developing some really exotic technologies ranging from point-to-point FTL travel to wormhole-like jump drives.

    If the laws of physics permits, such a discovery might be what provides the justification for investors and government agencies alike.

    • I think if someone had a solid path to go down for developing FTL travel they would have no trouble finding funding. In fact I think that would have the effect of encouraging more missions like Kepler, so we would have good places to go once we got it working.

      I'd venture a guess (I'm not involved in anything similar to that kind of physics) that the kind of results that would lead to a radical new form of propulsion wouldn't come from a heavy focus of funding, but rather continued support of seemingly impr

    • yaha another planet to poop on ...

    • by grumbel ( 592662 )

      All the money in the world doesn't allow you to break the laws of physics. And even if you can construct a theoretical possibility of FTL, you will likely have a really hard time implementing it, i.e. for a wormhole you might need two black holes, which aren't exactly easy to come by and then you have to find a way to survive traveling through that thing and all that stuff. So not likely to happen. Much more likely that the Kurzweil's singularity will happen, we will all turn into a cyboard super race and t

    • with no intelligent life within 100 light years of earth

      1) FTL travel would have a purpose not just a science fiction wank-off
      2) People with lots of money can tell the collected governments of the world to go take a flying leap, that alone would be worth billions to right people
      3) maybe all those people saying "we need a homeland" well there you go.

    • In hindsight this entire post is me digressing, but I'm honestly not convinced. The general direction that the progress of the world is taking is one of the people in control locking down and controlling society so to advance their own personal gains as much as possible for the short time they are alive and/or in power. Knowledge of life on other planets and R&D on how to get there, doesn't make money, it only costs money. If possible, I imagine information like this would be censored as much as much as

  • by RyanFenton ( 230700 ) on Sunday March 22, 2009 @02:51AM (#27286189)

    There's an important distinction between it being hard to find an earthlike planet, and there not being an earthlike planet to find at all.

    Our mechanisms for finding planets are all in wobbles in the wavelengths from the light of stars. And because of that, we tend to only see the big wobbles, because small wobbles tend to get lost in the noise.

    It would be nice if we could shine a flashlight and get a real look out there, but in most cases, we'd never see what we shone light upon in our lifetimes.

    The universe is a HUGE freakin place, filled mostly with stuff we can't get a good clear look at yet.

    Entire worlds like ours are are both all we know, but at the same time, are too small for us to even notice in the grandness just outside our atmospheric window.

    Ryan Fenton

  • Once the search succeeds, the next questions driving research will be: Is that planet habitable? Does it have an Earth-like atmosphere?

    Also, will they mean the same thing by "water," even if their oceans are filled with XYZ?


  • by saiha ( 665337 ) on Sunday March 22, 2009 @03:28AM (#27286275)

    Finding a "twin" earth, no matter the distance (assuming if we can see it, we can get to it at some point in the future) is possible _the_ most important thing for the continuation of the human race.

    As for being harder than "we" thought, to me at least (IANAA) it seems pretty damn hard to me. Even if we find a planet that could have human life, would it have life on it? Would that life be toxic to us? etc...

    • Re: (Score:3, Funny)

      by Hognoxious ( 631665 )

      A "twin" earth finding us, no matter the distance (assuming if they can see us they can get to us at some point in the future) is possibly _the_ most important thing for the continuation of whatever intelligent species lives there.


    • Re: (Score:2, Offtopic)

      Finding a "twin" earth, no matter the distance (assuming if we can see it, we can get to it at some point in the future) is possible _the_ most important thing for the continuation of the human race.

      No it isn't. Humans are built for here. We are an evolving species and once the oil is gone and the metals we've dug up oxidise and wash into the oceans, we'll be right back to our neolithic lifestyle - you know - the one that worked for hundreds of thousands of years.

      Industrialism will disappear and we we r

    • possible _the_ most important thing for the continuation of the human race

      Wow, and here I was thinking it would be something much simpler: Like us learning how to manage our own planet and resources properly.

  • Time difference (Score:4, Insightful)

    by istartedi ( 132515 ) on Sunday March 22, 2009 @03:37AM (#27286307) Journal

    Of course, it will only be possible to tell if it was Earth-like X number of years ago. Since there are only a few stars within 100 light years, X will usually be more than 100. In the meantime, there could have been a planet killing asteroid, or an advanced civilization could have nuked itself. So, we can only really find "twin Earths" from the past. We'll never actually know what it's like until we go there...

    ...actually, even that's not true, in the sense that "we" means everybody on Earth. Only the travelers will know it's true. Earthlings will have to wait for the return trip or signal, to tell them that it *was* true. Even then, for most stars it would be your great-great-great.... children receiving the signal.

    Bottom line? The Universe's speed limit sucks. Where's the fuzzbuster?

  • We're all familiar with the term already.
  • by TFer_Atvar ( 857303 ) on Sunday March 22, 2009 @04:35AM (#27286491) Homepage
    After all, Battlestar Galactica did it.
  • Dump all the excessive population of this planet to the new one?

    Maybe send the Chinese there? :-)

    I hope the planets we find don't have gold or oil though...

    • Yes, we'll put all the middle managers and telephone sanitizers into a big B Ark ship. To save them from the giant mutant space goat.

  • ... am looking forward to welcoming our new "Flip That Planet" overlords.
  • Life... (Score:3, Insightful)

    by nscott89 ( 1507501 ) on Sunday March 22, 2009 @08:51AM (#27287369)
    According to theories of what the earth's atmosphere was like before life flourished, the atmosphere was full of CO2 and nitrogen. There was no oxygen. According to our understanding of the earth 4 billion yrs ago, the earth would be a VERY different place today if there were no life here because oxygen is a byproduct of photosynthetic life. I theorize that the moment we find a planet like ours, we will have found life on another planet.
  • Twin Earths? (Score:3, Insightful)

    by flajann ( 658201 ) <> on Sunday March 22, 2009 @09:15AM (#27287455) Homepage Journal
    I am always annoyed with the popular press phrases things like this. If we find an Earth-like planet orbiting some distant star somewhere, it will not be Earth's "twin". It will be a planet similar in some respects to Earth. Similar in some respects; different in others. There is no "twin" relationship, and the intelligent inhabitants of that planet, if any, may be rather annoyed by our arrogance.

    Speaking of intelligence inhabitants, it would be wonderful if we could detect such, but very unlikely, unless those inhabitants also happens to be at a technological development similar to ours, where they are leaking radio signals all over the place. Good candidates for SETI to focus its search. Maybe even the SETI@HOME crowd can put actuators on that satellite dishes to focus on said planet...

    The real killer here is that even if we did find a so-called "twin Earth", we wouldn't be able to do a whole lot about it. Sending a probe there would take thousands of years. Maybe we could do a massive interferometer in space to study the planet in more detail. Forget the manned mission fantasy so many have. We have yet to put a man out past the orbit of the Moon and we're going to travel to a distant star many light-years from Earth?

    The physics of Interstellar Travel is daunting, to put it mildly. When I was a kid diddling around with the Special Relativity equations, I was all elated until I realized the ENERGY required to make time dilation a useful thing -- for the travelers, anyway -- is way beyond anything we humans are likely to be able to do now and in the future -- if ever. And all those dreams I had as a young boy of going to the stars died.

    Later, I got into the whole Wormhole stuff, and read some of the stuff Kip Throne and others wrote, and got depressed again. Wormholes -- if they even exist -- is far more daunting in terms of energy requirement than even lightspeed travel, by many, many orders of magnitude!!!!!!

    Well, wonderful if we can find. But then we'll be more frustrated when we all have to face the realities of physics. Science Fiction lost a lot of its appeal for me because most of it turned out to be simple fantasy, impossible to achieve. My ignorance as a kid is gone.

    Meanwhile, we have made tremendous strides in Science and Technology since my teen years, the stuff of Science Fiction 30 years ago. We do live in a marvelous age. It's just that Interstellar Travel will not be a part of it. :-(

  • The question to ask is not weather there are "Earth" like planets out there. The work by Lineweaver's group already suggests that they are there (simply from a proability basis). The question to ask is where they are relative to our state of development? And if one truly understands computer science, and life science, and nanotechnology, then they are out there, they are developed (much further along than we currently are) and they have most probably have evolved into a Matrioshka Brain architecture. Wh

    • The work by Lineweaver's group already suggests that they are there (simply from a proability basis). The question to ask is where they are relative to our state of development?

      There is little point in asking a question we can't yet answer. Finding one is a necessary precursor to answering that question.

      And if one truly understands computer science, and life science, and nanotechnology, then they are out there, they are developed (much further along than we currently are) and they have most probably have

      • by bradbury ( 33372 )

        Worthwhile question. Are we the members of an exclusive club or are we the members of a somewhat more global club?

        And the current answer is that we just do not know. The answer is interesting either way. But we have to determine which way it goes.

        I am voting on the "more global club" basis simply based on the odds of development and when they took place. But I could be very wrong.


  • Is the goal really to find "earth-like" planets (ones are similar, size, dist from star etc) or to find "habitable" planets which could support life somewhat like us or (maybe someday) us.
    These planets could very well exist at different distances as moons of gas giants that are closer to the star than our gas giants (which might provide supplimentry heat) and while these would probably be smaller, many gg moons are not much smaller than earth. Needless to say, these are going to be really hard to pick out

The shortest distance between two points is under construction. -- Noelie Alito