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Shortlist of Possible ET Addresses 136

Posted by ScuttleMonkey
from the he-phoned-home-just-trace-the-call dept.
An anonymous reader writes "Yahoo News is reporting that Astronomer Margaret Turnbull of the Carnegie Institution has released a 'top 10' list of potential inhabitable star systems. NASA is planning on using this top 10 list as the targets for their Terrestrial Planet Finder a 'system of two orbiting observatories scheduled for launch by 2020.'"
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Shortlist of Possible ET Addresses

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  • Keeping it secret (Score:4, Insightful)

    by Monkeys!!! (831558) on Sunday February 19, 2006 @05:39AM (#14753769) Homepage
    "...private philanthropists who pay for the bulk of their work may find out first when and if extraterrestrial life is discovered." I think that in the event of finding E.T life, SETI just might, you know, tell some other people as well.
    • Re:Keeping it secret (Score:1, Interesting)

      by Anonymous Coward
      I think that in the event of finding E.T life, SETI just might, you know, tell some other people as well.

      But only after the financers have placed their bets on the stock market.

      And if the transmission contains suitable material filed a few patents. (Or does LGM tech constitute prior art?)

      • Re:Keeping it secret (Score:2, Interesting)

        by Monkeys!!! (831558)
        "But only after the financers have placed their bets on the stock market.

        And if the transmission contains suitable material filed a few patents. (Or does LGM tech constitute prior art?)"

        I would like to think that the contract the private investors sign to be involved states that all information gained from transmissions are public domain. Then again the project might be desperate enough for money that they would allow the investors to keep control of what they recieve.
  • by Anonymous Coward
    What's their phone numbers? ;)
  • by wisebabo (638845) on Sunday February 19, 2006 @05:45AM (#14753789) Journal
    While the chances of hearing from alien worlds is depressing small ("Rare Earth"), still the thought that a few private individuals will know first should give us pause. If there is more information in the detected signal than "hello there", who knows what could be learned? Markets may move in a big way (here's how antigravity works, immortality, existence of god, a big black hole is headed your way, etc.).

    Then again if that's the only way we're gonna get these projects funded, perhaps these philanthropists should be rewarded for their risk taking.
  • by thue (121682) on Sunday February 19, 2006 @05:47AM (#14753794) Homepage
    The Terrestrial Planet Finder [wikipedia.org] has been cancelled:
    http://www.spaceref.com/news/viewnews.html?id=1092 [spaceref.com]
    So this list seems redundant. To bad, as it was NASA's most exciting project IMO.

    But there is still ESA's Darwin [wikipedia.org], an essentially identical project, which is still scheduled for a 2015 launch as far as I am aware.
    • Have you ever heard of things called "propaganda"?

      And "cancellation" and "postpone indefinitely" mean different things. I think that TPF is listed as the latter (but correct me if I am wrong, of course!).
      • Propaganda ? (Score:3, Insightful)

        by aepervius (535155)
        Cancellation means that you attract attention and maybe protest from Joe Q Public. Posponed indefinitly means you won't get as much heat on you, and still have the same results. De Facto, those are two of the same effect for a project (stopped and get no funding), just one is with a more "softer" on PR...
      • Have you ever heard of things called "propaganda"?

        If you are trying to imply something then I don't get it.

        And to me, "cancellation" and "postpone indefinitely" sound very much like the same thing; the two terms seems to me to be equivalent in terms of actual consequences. Hence I think that translating NASA's "postpone indefinitely" into "cancelled" is not misleading. (see also the article I linked)
    • Indeed. Apparently sending live meat to dead rocks is seen as more important than continuing with NASA's fabulously successful exobot ideas. The Webb 'scope will also be killed, probably about the time Hubble de-orbits.
    • As have the Keck Outriggers, which would have upgraded the interferometry capabilities of that facility (already the top in the world for optical/infrared astronomy). Their proponents were expecting to be able to image planets around other stars. (As opposed to just detecting them via the slight gravitational wobble they cause in the stars, or getting really, REALLY lucky and having one in an orbit edge-on to us transit the star. :) Keck already hunts planets, and the outriggers would have been a step up
    • As Michael Griffin explains in Griffin Builds Hopes For Terrestrial Planet Finder And Hubble Rescue Missions [spacedaily.com].

      The short reason is that the Crew Exploration Vehicle takes priority.

    • The Terrestrial Planet Finder has been cancelled:

      The article you linked says it has been defered. The cancelling part was the author's embellishment. This is happening because NASA administrator Griffin is responsibly trying to balance the retirement of the space shuttle, the completion of ISS, and the development of the CEV. Something has to give, it is space science. They've had a heck of a run. Look on the bright side. Extrasolar science is advancing rapidly without a TPF. The extra few years until i

      • "delayed indefinitely" is NASA speak for cancelled.

        For more information on the cancelled science mission see The planetary Society [planetary.org] which has been fighting Congress for science mission funding for years. You don't have to be a member to help out.

        • Astronomy and planetary science have been well funded for 15 years. There great new missions in the pipeline. Progress continues to be made in extrasolar studies. NASA space science is as healthy as it has ever been. The Planetary Society is nothing more than a greedy lobbying organisation that takes with both hands. They will never be satisfied. They are no different from AARP or AFLCIO. I hardly consider their views on the direction of the US space program to be mainstream. I would not dream of helping th

  • hmmm (Score:5, Interesting)

    by smash (1351) on Sunday February 19, 2006 @05:47AM (#14753796) Homepage Journal
    Apparently some systems were "tossed out" because they aren't stable enough (variable stars, strong gravity, etc).

    Now, is it just me, or does the idea that life may well need some abnormal event to kick-start it in conflict with that very idea?

    Perhaps include *some* of these systems?

    smash.

    • Re:hmmm (Score:1, Interesting)

      by thedletterman (926787)
      I don't see anything wrong with their reasoning. Instable environments don't produce abnormal, life-forming events, they regularly produce events that are hostile to life. I saw a screening of a film last year at USF called The Privledged Planet [discovery.org]. Admittedly, it gratuitous in support of "purposeful design", but they did a great job of approaching what makes Earth so suitable for life using a myriad of fields. It may suggest life with a purpose, but it was strongly pro-science, and probably worth a watch, ev
      • Instable environments don't produce abnormal, life-forming events, they regularly produce events that are hostile to life.

        But the earth is only 4600 years old, so there's nothing preventing an intelligent designer from popping by these unstable systems every so often and re-Genisising.

        (Why yes, this is flamebait, thanks for asking!)
    • That's missing the point of the entire exercise. They are trying to concentrate on systems most similar to our own since a) we know life can exist in circumstances like ours and b) if life does exist there, it may well take forms similar to life on earth so we will be able to recognise it. Concentrate on the easy stuff first and then, if that fails, try some more "abnormal" avenues.
    • "does the idea that life may well need some abnormal event to kick-start it in conflict with that very idea?"

      Well, it's very unlikely that you find a planet that, for example, has its temperature constantly changing to carry an advanced form of life. Simply because it's unlikely to find there life that has lived under these bad conditions long enough to have evolved into some advanced form, etc..

      It's unlikely, not impossible, but these guys at the NASA are just looking at the systems where life is the most

    • I think you're on the trail of something important. In stable environments you get turtles and lizards. They can easily outcompete a life form that spends 500 calories a day just idling its brain and which needs a decade to teach its young to be at all self-sufficient.

      The ruinous cost of a human brain can only be paid back in an environment that's variable enough to put a premium on adaptability. Otherwise "fitness" seems to map to "reproduce early and often".
  • Immigration? (Score:3, Interesting)

    by opencity (582224) on Sunday February 19, 2006 @05:59AM (#14753822) Homepage
    "I've chosen five to advertise the very best places to move to if we had to, or to point the telescope at," she told the BBC.

    An open call for science fiction references if there ever was one.

    Her criteria include a temperate zone that can support copious amounts of liquid water. If we're moving, I agree. There are chemical reasons we think life would be predisposed toward water but there could be different biochemistries. Any biochemists out there feel free to disagree and/or expound.

    This story is also a good test of the slashdot equivalent of Godwin's law. How long until the usual sectarian debates spring up (and I don't mean MS)
    • Re:Immigration? (Score:5, Interesting)

      by cruachan (113813) on Sunday February 19, 2006 @07:19AM (#14753984)
      "Any biochemists out there feel free to disagree and/or expound."

      I'll take that one. In a liquid water environment it's difficult to see how you'd end up with a biochemistry that wasn't nucleic acid, protein, carbohydrate and fatty acid based. By observation life on earth seems to have explored just about every type of possible molecular structure that carbon/hydrogen/oxygen + other minor elements can produce and if there were some other useful biological molecule then it's difficult to imagine why it's not been 'discovered' and exploited already. That's not to say that the details won't differ - I'd have thought it virtual certain that a mix of different nucleic acids and amino acids would be used in different combinations with a different genetics etc etc, but I'd expect life to be grossly similar on similar planets, just differing radically in the details.

      Outside that I'm very unconvinced by non-water or carbon based life. Silicon just doesn't form complex enough molecules so that's out. The next best bet seems to me to me ammonia based.
      • I'll take that one. In a liquid water environment it's difficult to see how you'd end up with a biochemistry that wasn't nucleic acid, protein, carbohydrate and fatty acid based.

        I'd be very astonished to learn that all life on all planets uses the same DNA/RNA combination we use. There almost certainly are other combinations of amino acids that can be used for the coding, and different chemicals for the backbone. It may be that DNA/RNA simply got started first and spread fast enough that the alternative

        • Re:Immigration? (Score:5, Informative)

          by cruachan (113813) on Sunday February 19, 2006 @04:47PM (#14756208)
          That's what I'm saying. I'd be highly suprised if alien life used precisely the same biochemistry, however I'd be equally suprised if it didn't use nucleic acids, amino/acid/proteins, sugars/polycarbohydrates and lipids. These grouping are too useful and easily available for them not to be used.

          We can even reasonably be a bit more precise about it. With proteins of the 20 amino acids in prime use a good dozen of them could be expected to turn up in an alien biochemistry just because they're the simplest that do the job. With the carbohydrates many are also a dead certainty - glucose, fructose etc. and polymers like chitin are certain to be just as useful to alien biochemistry as they are to ours. On the lipid front, wll lipids are lipids and our biochemistry uses just about everyone going anyway so there's certain to be major overlap.

          Nucleic acids are more interesting though. I'd lay a bet on RNA just because the ribonucelic acids tend to form easily in prebiotic conditions. DNA is more suspect, particularly as life here can get along without it just fine. Nevertheless it's the next simplest step up from RNA so may be favoured against other varients. Of course which nucelic acids are actually used is open to chance, although it's noticable that the ones we have are among the simplest.

          Beyond these broad categories though indeed it gets more speculative. Even so, some assumptions seem probable. For example if there is RNA/DNA then a triplet genetic code is likely, because as has been observed, a doublet code doesn't give you enough combinations to work with (but there is evidence that our early genetic code was doublet and we evolved the triplet later) whereas a quad code would be inefficient needing 33% extra DNA to code and more error prone.

          Other things that might also be expected to turn up. For example porphorins (the building block of haem, chlorophyll and many other useful molecules).

          Unfortunatly I guess we'll never know, unless we strike lucky on Mars or Europa.
      • carbon/hydrogen/oxygen

        and nitrogen. Nitrogen's not exactly a minor element with organic compounds.

        Other elements (like sulphur for amino acids, or magnesium for chlorophyll) are very, very rare, and I wouldn't be surprised if you could build a full biochemistry with just CHON - just much more inefficient than our current one. The one thing I'm not sure that life could build with just CHON is a photoreceptor - the metal-free pigments all seem to be accessory pigments only. This, actually, is an interesting p
        • There's a theory that just like solar systems, galaxies have a 'habital zone' around the core - too far in and the stars formed before there was enough heavy metals to support life. If so it would be a nice explanation as to why we havn't seen any signs of intelligent life out there yet.

          Incidently I life would manage to get by with scarer metals. There's a group of molluscs with vanadium-based blood, which is a couple of orders of magnitude rarer in the crust than iron.
          • Blood I can understand - there's a fair amount of different blood chemistries out there.

            But photoreceptors and energy storage molecules I'm not so sure about. Everything uses ATP and every plant uses chlorophyll. I'm not sure life could really manage in a phosphorus/magnesium poor area.
        • The big coincidence, of course, is that if you exclude helium (chemically inert), those four elements are also the most common in the Universe.

          A big coincidence, or a sign of Intelligent Design?
    • Her criteria include a temperate zone that can support copious amounts of liquid water. If we're moving, I agree. There are chemical reasons we think life would be predisposed toward water but there could be different biochemistries. Any biochemists out there feel free to disagree and/or expound.

      IANABC ... but, maybe it's just as simple as we can only conceive life in ways that are familiar to us? While it's possible that life could exist in forms we can't even guess at, we don't have any criteria to look

  • by sanman2 (928866) on Sunday February 19, 2006 @06:08AM (#14753839)
    This search for 'habstars' (habitable star systems) is really fascinating, and perhaps even practical in an offhanded way. What better way to inspire future astronomers and astrophysicists than to find some beautiful blue-green jewel like ours out there, even if we can't detect signs of intelligent life.

    This would be a lot more motivating and captivating than scanning the heavens for shapes of creatures from mythology, which is no better than looking for pictures of Jesus or the Virgin Mary in a cheese sandwich.

    Once we find something out there worth travelling to, then it would automatically spur thoughts of developing means to get there. Even if such dreams aren't possible due to the limits of known physics, it's still a noble and instinctive goal, like our grazing ancestors had in seeking greener pastures. Who knows where such thoughts might ultimatley lead?
    • You raise an excellent point, and reminds me of the sense of wonder that inspired westerners in the 15th and 16th centuries to set sail for lands that existed only in legend. (Of course, they probably had rough maps purchased from the Chinese, who had been to these places 75 years earlier).
      • > the Chinese, who had been to these places 75 years earlier ...and pulled back, because the mandarin bureacracy had decided to stop funding these expeditions on the basis that they had little practical value, while there were problems at home of more pressing concern to be dealt with.

        A lesson for our times, indeed.
    • > This would be a lot more motivating and captivating than scanning the heavens for shapes of creatures from mythology

      That's not what astronomers do. That's not even what amateur astronomers do.

      The constellation-based naming system is just a convenient way of finding your way around the sky because it leverages the human mind's facility for pattern recognition and it's a billion times easier than trying to remember thousands of ascension and declination co-ordinates which change every minute.

      The constell
  • by Quirk (36086) on Sunday February 19, 2006 @06:08AM (#14753840) Homepage Journal
    The Royal Society is holding a symposium on the origins of life...

    Life on Earth 'unlikely to have emerged in volcanic springs' [royalsoc.ac.uk]

    13 Feb 2006

    "The latest findings of experiments to re-create the conditions under which life could emerge from chemical reactions suggest that volcanic springs and marine hydrothermal events are unlikely to have provided the right environment, a leading researcher from the United States will tell an international meeting tomorrow (14 February 2006) at the Royal Society, the UK national academy of science."

    In the alternative Plos ran an interestin article titled Jump-Starting a Cellular World: Investigating the Origin of Life, from Soup to Networks [plosjournals.org] which touches on the front running theories on the origin of life.

  • by SirFlakey (237855) on Sunday February 19, 2006 @06:31AM (#14753887) Homepage
    If memory serves me right ET was after a PHONE Number not his home address.
  • Why not? (Score:1, Funny)

    by Shanesan (955683)
    The US Government, supposedly the most wealthy in the world, keeps breaking all of their promises. Peace, a stable economy, and now they take their stargazed eyes and focus them significantly closer to home.

    At the rate we're going, by the time we actually need to get off this planet because we've hollowed it out and destroyed the O-Zone....

    Congressman1: Alright, we're about to die. Any ideas?
    Congressman2: We can up and move to another planet.
    Congressman1: Great idea! Get us a list of inhabitable planets!
    Sec
  • So why are we looking for life on planets we won't be able to get data back after a generation later? This really fits the meaning of "shooting for stars". After waiting 50 - 100 years, find out there is nothing there? So what if we do find life on planets, then what? What exactly does that prove or provide when we can't even all agree on evolution on Earth? Not to mention how to detect "life" on other planets.

    What exactly is the point? Life is out there, I like to believe, but until I can see, feel,
    • Yet another reason for switching from IP4 to IP6 addresses.
    • So why are we looking for life on planets we won't be able to get data back after a generation later?

      I hate to break it to you, but the world will go on after you die. There will be people just as bright and interested in things like this as you are (or aren't).

      Astroscience is about advancing the species, not the nation, not the corporation, not the individual, but humanity itself. In space are the answers to all of our questions (origins of life, divinity or lack thereof, the nature of sentience, pos

    • From what I've read, some of the stars are under 5 light years away. That's within near today technology to send a probe and get information back within somebody's lifetime. Say, 30 years to for it to get there, 5 years back.

      Of course, we need to improve some more on artificial intelligence. We don't need something that can converse, but we do need something that can make decisions about proper behavior for unexpected events.
      • From what I've read, some of the stars are under 5 light years away. That's within near today technology to send a probe and get information back within somebody's lifetime. Say, 30 years to for it to get there, 5 years back.

        I think 30 years to get there is a little optimistic.

        It took 26 years for Voyager to leave our Solar System. Even with ion-drive spacecraft (still in their infancy, and very experimental) I doubt we'd get anywhere near 1/6th the speed of light your 30 years would suggest.

        Short of some

        • Well, to be fair, we're still improving the technologies for viewing them from home, bigger and better telescopes and such.

          I figure that we have at least two more generations of remote detection methods before we'll have to send a probe to get more detail. Meanwhile, we might as well use them to get more detail, the more we know the better the probe can be. It's not like we're in a huge hurry right now.

          Voyager's been on a ballistic course for most of it's journey, if I remember correctly. Yes, we do have
        • Short of some major technology breakthroughs

          Not really. If you could get past the rabid enviroloons who shit bricks every time someone says the word 'nuclear', a relatively simply Orion-style probe could reasonably be expected to achieve a velocity of 10% or more of the speed of light in short order. And it could carry enough fuel to slow down for orbital insertion once it reached the target system, using that same power to boost one hell of a signal back to Earth about what it sees.

          That means that a syst
          • If you send one of these nuclear rockets into space, it might kill some of the cyano-algae that is going to start the life cycle on some planet in a couple billion years, thus making it impossible for that future civilization to exist. :)

            Seriously, I have to agree that the uber left-wing idiots against nuclear energy are clueless as to its potential. Of course I've already seen environmentalists complaining about the effects of open pit mining on the Moon damaging the environment... and studies to complain
    • So why are we looking for life on planets we won't be able to get data back after a generation later? This really fits the meaning of "shooting for stars". After waiting 50 - 100 years, find out there is nothing there?

      Why not? It's not like the human race would be sitting around doing nothing during that time. We just leave a note for the next generation reminding them to check the inbox every once in a while.

      If we did get a response it would probably be more than just "Got your message, please reply."
      • If we did get a response it would probably be more than just "Got your message, please reply."

        No, it would probably be some sort if intergalactic smiley: %*&. An we'd figure that the pointy bits were probably teeth, and get all pissed at them, so we'd send them a snarky message back, and then it's just flame-flame-flame for a few millennia.

        (Of course on the planet Arkthon IV you have to turn your head to the right rather than the left to read the smileys.)
        • No, it would probably be some sort if intergalactic smiley: %*&. An we'd figure that the pointy bits were probably teeth, and get all pissed at them, so we'd send them a snarky message back, and then it's just flame-flame-flame for a few millennia.

          (Of course on the planet Arkthon IV you have to turn your head to the right rather than the left to read the smileys.)


          Except for the lefthanded smileys, a lot like slashdot. (-:
    • If Heim Drive [slashdot.org] works out, several of the top contenders are under 200 days away...
  • by deolaudamus (955686) on Sunday February 19, 2006 @06:54AM (#14753931) Homepage
    This "listing," "research," and "entire project" is all just for show...we've actually been travelling the galaxy to other habitable (and inhabited) planets from a secure facility inside Cheyenne Mountain--kinda surprised nobody mentioned that already! In fact, we've made friends with several other worlds and they joined our fight and helped us defeat a race of nasty snaky guys! Oh, and if anyone wielding a creepy glowing staff promises you candy for reading his book on Origin, run FAST. Sheesh...old news what?
  • Are they looking at Zeta Reticuli? http://www.gravitywarpdrive.com/Zeta_Reticuli_Inci dent.htm [gravitywarpdrive.com]
  • by zpok (604055) on Sunday February 19, 2006 @07:18AM (#14753983) Homepage
    Yeeeey, let's find some things to kill!
  • just 10? (Score:4, Funny)

    by wwmedia (950346) on Sunday February 19, 2006 @08:27AM (#14754141)
    just 10? our intelligent designer has been busy!
  • by Sentsix (128268) on Sunday February 19, 2006 @09:07AM (#14754211) Homepage
    NASA isn't looking for ET's phone numbers, they're confirming Gate addresses. It's only a matter of time before McGyver and team of Air Force officers are heading out into the galaxy to do battle with the Gua'uld!
  • by Dachannien (617929) on Sunday February 19, 2006 @10:59AM (#14754521)
    She said NASA once had a policy of what to do, whom to call, and how to announce the news if someone detected a signal of intelligent life from space. "Today it is in fact a group of very generous philanthropists who will get the call before we get a press conference," Tarter said. They include Microsoft co-founder Paul Allen and Microsoft chief technology officer Nathan Myhrvold.

    Crap. You can bet the aliens will end up with Windows on 90% of their desktops before they even hear of Linux.

  • From the article:

    She said NASA once had a policy of what to do, whom to call, and how to announce the news if someone detected a signal of intelligent life from space.

    "Today it is in fact a group of very generous philanthropists who will get the call before we get a press conference," Tarter said. They include Microsoft co-founder Paul Allen and Microsoft chief technology officer Nathan Myhrvold.

    Does anyone else find it disturbing that funding for basic science is suffering from such severe cuts? It s

  • Just look at some of the life that grows in a college student's dirty laundry pile. Scary.

    You never know what situations you might create life in.
    • Just look at some of the life that grows in a college student's dirty laundry pile. Scary.

      You never know what situations you might create life in.

      Funny you should say that. My Mum once bought this round rack thing with three bottles in it, meant for fancy cooking and what not.

      In one of the bottles was, if I remember it correctly, balsamic vinegar and extra virgin olive oil.

      Because of the densities of the liquids, they tended to settle, light on top, dark below.

      Long story short, Mum never

  • by mattr (78516) <mattr AT telebody DOT com> on Sunday February 19, 2006 @11:34AM (#14754641) Homepage Journal
    TFA sucked but wading through the net produced these notes and links.

    Here [nasa.gov] or here [astrobio.net], a very nice article on the project, "Margaret Turnbull and Jill Tarter have a new list, called HabCat: A Catalog of Nearby Habitable Stellar Systems." (2003) Interview included.

    Interesting that starting with the Hipparcos catalog of 120,000 stars and skipping all with major problems for life ("cataclysmic, eruptive, pulsating, rotating, or X-ray stars", low metal content systems, rotating too fast or too much UV or bad size or composition), left 1 star in 6 still potential life bearers.

    Wiki on HabCat [wikipedia.org] and Turnbull [wikipedia.org]. The Turnbull page has a link to a PDF, which is a very interesting scientific paper about how the list of habitable stars was made.

    Wiki article [wikipedia.org] on the Terrestrial Planet Finder, which uses Turnbull's list of 5000 candidates within a 100 light year radius. List of Top 100 candidates. Note 18 Scorpii at 46 light years is number 62 in the list, and 37 Geminorum is not listed.

    The highest ranked 2 candidates in that list are just 4 ly away from Earth, at Rigil Kentaurus, and then Tau Ceti at 12 ly. There is one at 3 ly and some others at 19, 20, 24 ly too.

    Allen Telescope Array [seti.org]

    Turnbull's top 10 list includes 51 Pegasus, where in 1995 Swiss astronomers spotted the first planet outside our solar system, a Jupiter-like giant.

    Others include 18 Sco in the Scorpio constellation, which is very similar to our own sun; epsilon Indi A, a star one-tenth as bright as the sun; and alpha Centauri B, part of the closest solar system to our own.

  • I found this paragraph highly concerning "Today it is in fact a group of very generous philanthropists who will get the call before we get a press conference," Tarter said. They include Microsoft co-founder Paul Allen and Microsoft chief technology officer Nathan Myhrvold. Is this for real? NASA (who pulled funding on SETI years ago) is now asking them for free advice and the Microsoft bosses are going to be the first ones to get the heads up on ET civilizations? Damn, that could be dangerous for more reaso
  • by xant (99438) on Sunday February 19, 2006 @01:22PM (#14755074) Homepage
    Send them a message containing the link: Click here to be removed from our mailing list. [berkeley.edu].
  • It is unfortunate that Turnbull, the Carnegie Institution and NASA chose to affiliate themselves with the Search for Extraterrestrial *Intelligence*. TPF might be capable of locating "water worlds" but there is no experimental information with regard to what fraction of those might have no water or be entirely covered in water (water worlds). It seems obvious that planets like Venus and Mars do not support life or may have only supported it for a brief period (in large part because they are near the edges of the habitable zone). It is also difficult to envision how intelligent life, particularly intelligent life with robust technology (radio transmitters, integrated circuits, rockets, etc.) would evolve on planets entirely covered in water. So one needs to make careful distinctions between systems with dead planets, systems with only water covered planets (pure water worlds), systems with water worlds with primitive life (e.g. those before the Earth's current stage of development), systems with water worlds with intelligent life (our current stage) and those beyond our stage.

    Lets do the math. Universe, ~13 billion years old. Earth, ~5 billion years old. Time to develop first sun-like stars perhaps 1 billion years. So there is a reasonable chance that there are (or were) Earth like planets up to 7 billion years older than Earth (at least around stars slightly smaller than the sun which age more slowly). There are some systems with younger Earths (*much* younger for those systems currently in the process of planetary formation). Lineweaver's group has worked on this and has concluded that ~70% of the Earth's in the galaxy are older than ours -- many of them by billions of years.

    Based on this it is unlikely that either TPF or SETI (based on its current approaches) will discover "intelligent" life. The statistics dictate that you only have perhaps a 5000 (years) / 12,000,000,000 (years) chance (less than 1 in a million) of finding a planet which hosts "intelligent" life as we know it.

    For those systems with terrestrial sized planets and those with water TPF is a reasonable effort -- it might manage to detect water and if lucky atmospheric composition that could hint at life. However pointing the SKA (or any other radiotelescopes) at the stars in the list provided are highly unlikely to be successful because they assume intelligent civilizations which are currently at (and remain at) our stage of development. (This changes the statistics to about 1 in a billion.)

    The reasons for this are as follows... Whether you believe in steady state growth (Dyson's assumption in 1960), or exponential growth as "The Singularity [wikipedia.org]" concept proposes the bottom line is that it seems very unlikely that a civilization would actively choose to remain at our state of development (i.e. zero growth for millions or billions of years). If you choose the steady state model the time to develop to a Dyson Shell is measured in a few hundred to a few thousand years. If you choose the singularity model then the time to develop a Matrioshka Brain [aeiveos.com] (also here [wikipedia.org]) is measured in decades. Once either of those states is reached the star goes "dark". So the star list is useless (to either the TPF mission or SETI) for identifying locations of intelligent civilizations with capabilities even slightly beyond our own.

    Robert Bradbury

    Notes:
    For the above calculations I chose 5000 years as the longevity of humans with a reasonable level of technology development. One could limit it to smaller time frames (~100 years for radio or 40-50 years for lasers or rockets). TPF has a much greater chance of being successful than radio or optical SETI because it is working with a much larger time window. Water world longevities range from 100 million to many billion years if they restrict themselves to sun-like (

    • Whether you believe in steady state growth (Dyson's assumption in 1960), or exponential growth as "The Singularity" concept proposes the bottom line is that it seems very unlikely that a civilization would actively choose to remain at our state of development (i.e. zero growth for millions or billions of years). If you choose the steady state model the time to develop to a Dyson Shell is measured in a few hundred to a few thousand years. If you choose the singularity model then the time to develop a Matrios
      • P.S. I was not aware of the "Matrioshka Brain" concept until now, but file that in the pseudo-scientific myth category as well.
      • "The Singularity": This is a whopping big superstition, sometimes referred to as "the Rapture for atheists."

        I heard someone call it "The Rapture of the Nerds" which I think is more apropo.

      • I agree with pretty much everything you've said except for your disdain over the possibility of achieving practical immortality. Only the rankest of fools could possibly think that we'd somehow manage to keep progressing technologically in all fields, yet somehow forever be subject to some mystical "Law of Death" which confounds all efforts to extend life and defeat the process of aging. That smacks of nothing more than religious superstition.

        There's nothing special about aging and death. It too will yie
  • My roommate actually spent a couple of hours looking up these solar systems to search for aliens with Celestia before I smacked him upside the head. Please if there are kids reading this, don't drop out of school. *For those of you who don't know, Celestia is software that maps and lets you travel around in space.*
  • Probably I'm blind or just getting old.

    Can anyone post a link which INCLUDES the ten systems/stars and is not jsut babble?

    angel'o'sphere
  • ... what are the Stargate addresses for those ten? :)

    Bruce
  • by SirBruce (679714) on Sunday February 19, 2006 @09:09PM (#14757768) Homepage
    The submitter got it slightly wrong. First off, Margaret Turnbull's team came up with a list of 17,129 potentially habitable star systems in 2003, and the work she has done since has been to refine that list.

    What she announced yesterday were TWO "Top 5" lists. The first list includes the top 5 recommendations for a SETI search:

    beta CVn
    HD 10307
    HD 211415
    18 Sco
    51 Pegasus

    The second list includes the top 5 recommendations for the TPF to examine for Earth-like planets:

    epsilon Indi A
    epsilon Eridani
    omicron2 Eridani
    alpha Centauri B
    tau Ceti

    Why the difference? Well, the second list is of much closer stars, and much more likely to have planets that TPF can find and image. The first list has stars that are a bit farther away, but are, generally speaking, more like our Sun.

    And here's a useful link:

    http://www.aaas.org/news/releases/2006/0218habitab le.shtml [aaas.org]

    Bruce

It is not for me to attempt to fathom the inscrutable workings of Providence. -- The Earl of Birkenhead

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