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Space Science

Sun's Twin Discovered — the Perfect SETI Target? 168

astroengine writes "There are 10 billion stars in the Milky Way galaxy that are the same size as our sun. Therefore, it should come as no surprise that astronomers have identified a clone to our sun lying only 200 light-years away. Still, it is fascinating to imagine a yellow dwarf that is exactly the same mass, temperature and chemical composition as our nearest star. In a recent paper reporting on observations of the star — called HP 56948 — astronomer Jorge Melendez of the University of San Paulo, Brazil, calls it 'the best solar twin known to date.' Using HP 56948 as a SETI target seems like a logical step, says Melendez."
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Sun's Twin Discovered — the Perfect SETI Target?

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  • by zaft ( 597194 ) on Friday April 27, 2012 @05:42PM (#39827597) Homepage
    First post?
  • Exo Plant first (Score:3, Insightful)

    by Anonymous Coward on Friday April 27, 2012 @05:42PM (#39827603)

    It would be a good target to look for an Exo plant first. Then from spectral measurements see if it has the elements necessary for life (water, oxygen, etc...). Then it makes a good target for SETI to scan.

  • by Dunbal ( 464142 ) *
    "Only" 200 light years. Sigh.
  • Pointless? (Score:5, Insightful)

    by hawguy ( 1600213 ) on Friday April 27, 2012 @06:00PM (#39827813)

    Unless we think a civilization is intentionally sending out beacons to the universe, isn't SETI pointless?

    As our communications technology improves, it becomes lowered powered (unlike my old 3W car phone, my curren cell phone only puts out 300mW of signal max) and the leakage from hundreds, or thousands, or millions of point sources of RF signals becomes more and more like "white noise" to someone that doesn't know how to decode it thanks to spread spectrum signals and high bandwidth data encoded in the streams.

    The days of 100,000+ watt AM radio transmitters will likely end soon, so there won't be nearly as much leakage to the cosmos.

    So there's probably a 100 year window in a civilization's development where its unintentional broadcasts are detectable.

    Will we ever intentionally send out a beacon advertising our existence, knowing that it would likely take 100 years or more before any potentially inhabited planet would receive it? And if we do think there's other life out there, do we really trust it enough to tell it where we are?

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

      by Eponymous Hero ( 2090636 ) on Friday April 27, 2012 @06:08PM (#39827903)
      don't know how to break this to you so i'll just say it... http://en.wikipedia.org/wiki/Voyager_Golden_Record [wikipedia.org]
      • by hawguy ( 1600213 )

        don't know how to break this to you so i'll just say it... http://en.wikipedia.org/wiki/Voyager_Golden_Record [wikipedia.org]

        I think it's safe to say that Voyager (or Pioneer) probes will never be found. Space is big. Very big. Voyager is small. Very small.

        I think the Star Trek scenario of a Voyager probe being used as target practice by a Klingon warship is equally likely as it being found at all.

        • ok, but that's not what you asked.

          Will we ever intentionally send out a beacon advertising our existence, knowing that it would likely take 100 years or more before any potentially inhabited planet would receive it? And if we do think there's other life out there, do we really trust it enough to tell it where we are?

          the answer is yes. a long time ago.

          • by hawguy ( 1600213 )

            ok, but that's not what you asked.

            Will we ever intentionally send out a beacon advertising our existence, knowing that it would likely take 100 years or more before any potentially inhabited planet would receive it? And if we do think there's other life out there, do we really trust it enough to tell it where we are?

            the answer is yes. a long time ago.

            Well, that's not really what I asked. A small piece of low speed space junk that has no chance of discovery is not the same as a radio beacon.

            Bonehead's response below is exactly what I asked about, but it's interesting that they directed it at a star cluster 25,000 light years away knowing that in 25,000 years it will no longer be there.

      • Re:Pointless? (Score:4, Informative)

        by bonehead ( 6382 ) on Friday April 27, 2012 @06:15PM (#39827973)

        Don't forget this one: http://en.wikipedia.org/wiki/Arecibo_message [wikipedia.org]

        There have been many intentional messages sent.

        • Re:Pointless? (Score:5, Insightful)

          by Algae_94 ( 2017070 ) on Friday April 27, 2012 @06:47PM (#39828267) Journal
          I like how they mention that the 23 row by 73 column interpretation is "jumbled garbage". The correct image also looks like jumbled garbage. I especially like the image of a human. How the hell is an alien supposed to figure out what that is without having seen a human before?

          It is really expecting a lot out of an alien to receive this signal in all the space they could be looking at, determine that the modulation of the signal corresponds to binary digits, then determine this number of bits is semi-prime and can be arranged in a grid to pictorially represent the data, make sure they arrange it correctly, decipher what is essentially a cave drawing made by a species that may have close to nothing in common with them, and actually care enough to write back.
          • by hawguy ( 1600213 )

            I like how they mention that the 23 row by 73 column interpretation is "jumbled garbage". The correct image also looks like jumbled garbage. I especially like the image of a human. How the hell is an alien supposed to figure out what that is without having seen a human before?

            It is really expecting a lot out of an alien to receive this signal in all the space they could be looking at, determine that the modulation of the signal corresponds to binary digits, then determine this number of bits is semi-prime and can be arranged in a grid to pictorially represent the data, make sure they arrange it correctly, decipher what is essentially a cave drawing made by a species that may have close to nothing in common with them, and actually care enough to write back.

            It would be interesting to release that radio stream in some code breaking challenge to see how easy it is for an earthling to decode the message. Though most of the people that would participate in such an event probably already know about this message.

          • Basic maths (Score:5, Informative)

            by DrYak ( 748999 ) on Saturday April 28, 2012 @01:13AM (#39830175) Homepage

            I like how they mention that the 23 row by 73 column interpretation is "jumbled garbage". The correct image also looks like jumbled garbage. I especially like the image of a human. How the hell is an alien supposed to figure out what that is without having seen a human before?

            The most basic possible message: counting.
            Before the human-shaped pixel art, the sequence begins with a simple count, with increasing binary numbers from 1 to 10.
            It's a pattern, which is recognizable without any cultural reference, only with some knowledge of math, which is needed to handle the radio signal any way, and this pattern is clearly not a random occurrence. Turn the data the other way around and you don't see any easily recognisable pattern at the begin, so they know it's the wrong way.

            If you want to make it clear that a message is a message and not garbage, you try to cram in something that is clearly not random, but that is as simple basic maths as possible :
            counting from 0 to some number, list of prime numbers, fibonacci sequence...

            Then you could append whatever you want. Life forms at the receiving end might not be able to understand what you mean with your picture, but at least they now they've organised the data correctly because that's the only way where the begining makes some sense in a mathematical way.

    • They will be detected by the gamma ray bursts emitted by the nuclear warheads used in their epic space battles because we all know if an intelligent being is not war like they will never develop past being food.
    • So there's probably a 100 year window in a civilization's development where its unintentional broadcasts are detectable.

      Exactly. A civilization will go unnoticed if we don't detect its emissions that originate from the brief instant (relatively speaking) between their invention of radio and their understanding of information theory.

      And if we do think there's other life out there, do we really trust it enough to tell it where we are?

      It has, indeed, been pointed out that this is a really bad idea. [scienceblogs.com] Safe to s

    • Another one who thinks SETI listens for radio leakage. It doesn't. Let's just leave it at that since you obviously didn't feel the subject is even worthy of a brief google.

      Also google for METI [centauri-dreams.org] while you're at it. Whenever your conclusion seems to be that you are far more intelligent than a large group of scientists it may be time to check your premises. It is far more likely that you are the one who is ignorant or stupid.

  • by oliverk ( 82803 ) on Friday April 27, 2012 @06:04PM (#39827845)

    ...if what we were seeing was actually ourselves, just 400 years ago. A wormhole, acting as a mirror...floating at the point they're looking at?
    C'mon...you can dream, can't you?

    • by Beardo the Bearded ( 321478 ) on Friday April 27, 2012 @06:16PM (#39827989)

      Oh shit, warn them about Germany.

    • by jamesh ( 87723 )

      I had the same thought. A giant mirror in the middle reflecting everything (not just light). And if the planet appears 200 light years away then the mirror is 100 light years away and we are seeing ourselves 200 years ago, it should start getting noisy fairly soon!

  • "Hey Meepzorp, those creatures orbiting Zfeskew 73875.24543 are trying to communicate with us."
    "Man the relativistic bombs."
  • spin up the stargate and dial it!

  • Seriously? (Score:4, Funny)

    by Nom du Keyboard ( 633989 ) on Friday April 27, 2012 @06:38PM (#39828195)

    Seriously, there are 10 billions stars essentially equivalent to our Sun, but you have to go 200 light years to find the closest one?

    • It's just a matter of how high your standards are for something to be essentially equivalent. I mean, Alpha Centauri system is about 4.37 light years away, Alpha Centauri A is about 10% more massive than the Sun, Alpha Centauri B is about 10% less massive than the Sun. I say "Eh, close enough".

    • Because there are something like 200 billion stars in the Milky Way. Feeling insignificant yet?
  • Wrong name (Score:4, Informative)

    by gvanbelle ( 1400327 ) on Friday April 27, 2012 @06:41PM (#39828227)
    The star's ID isn't HP 56948, but HIP 56948 (from the Hipparcos satellite catalog), aka HD 101364, SAO 15590...
    • by Tablizer ( 95088 )

      The star's ID isn't HP 56948, but HIP 56948

      No, it's really a giant HP printer. It's where all your lost print-jobs have been going.

    • Thank you. Target acquired. [wikipedia.org] With a declination of 69 degrees this is definitely a northern star. I won't be able to reach it from my location. Most interesting nearby targets are in the southern hemisphere. This is a rare exception.

      In the constellation Draco. Apparent magnitude 8.7. It shouldn't be too hard to find with a telescope in a nice dark sky.

    • The star's ID isn't HP 56948

      I believe the only authoritative answer to this is what the star reports over its GPIB interface in response to the '*IDN?' command.

  • Yellow dwarf (Score:3, Interesting)

    by freeasinrealale ( 928218 ) on Friday April 27, 2012 @07:03PM (#39828407)
    Does this mean our sun is a yellow dwarf??
    • Technically, yes. That massive gravitational anchor we circle which provides all of our heat and light is a smallish star.
  • If it is the same age as well as chemical composition, both our sun and HIP 56948 may have been born out of the same stellar nursery. This would make it an even more amazing find.

    But, unless it has terrestrial planets in the Goldilocks zone, it is unlikely to to be a real prospect for SETI.
    • by slew ( 2918 )

      ...But, unless it has terrestrial planets in the Goldilocks zone, it is unlikely to to be a real prospect for SETI.

      If you actually read the paper, it appears from the spectral analysis, the authors conclude that HIP56948 should have about 1/2 the "rocky" material formed around it than our sun, and radial velocity measurements seem to exclude giant plants in the inner planetary region. So, although they cannot be sure there are or are-not rocky planets that are terran like in the Goldilocks zone (we don't have a reliable way to figure that out yet from ground based observations), the available evidence seems to indicat

  • Schematics (Score:5, Funny)

    by guttentag ( 313541 ) on Friday April 27, 2012 @07:26PM (#39828611) Journal
    I worry that China is broadcasting the source code for Windows Vista, and 200 years from now some alien civilization will receive it and think they're schematics for something great. They'll build it, nearly destroy themselves and then come looking for us.
    • by GiMP ( 10923 )

      To think, we invented the Descolada virus?

    • by canajin56 ( 660655 ) on Friday April 27, 2012 @10:00PM (#39829511)
      I think that scenario is in the EULA already, we should be covered.
    • by ignavus ( 213578 )

      I worry that China is broadcasting the source code for Windows Vista, and 200 years from now some alien civilization will receive it and think they're schematics for something great. They'll build it, nearly destroy themselves and then come looking for us.

      No problem. The aliens won't be able to activate their copies of Windows for another 200 years after they install it.

  • Think we'll go over there and find a planet just like Earth, but Rome never fell? Or maybe they had an experiment in causing immortality go horribly wrong?

    • by gl4ss ( 559668 )

      Think we'll go over there and find a planet just like Earth, but Rome never fell? Or maybe they had an experiment in causing immortality go horribly wrong?

      zardoz?

  • If Hodgkin's Law holds, there'll be nothing for SETI to pick up yet. Adjusted for the travel time, they're just about getting steam engines.

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