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Space Science

Exoplanet Count Tops 700 128

astroengine writes "On Friday, the Extrasolar Planets Encyclopedia registered more than 700 confirmed exoplanets. Although this is an amazing milestone, it won't be long until the 'first thousand' are confirmed. Only two months ago, the encyclopedia — administered by astrobiologist Jean Schneider of the Paris-Meudon Observatory — registered 600 confirmed alien worlds. Since then, there has been a slew of announcements including the addition of a batch of 50 exoplanets by the European Southern Observatory's High Accuracy Radial velocity Planet Searcher (or HARPS) in September."
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Exoplanet Count Tops 700

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  • by Anonymous Coward on Sunday November 20, 2011 @06:43PM (#38119498)

    I just spend the weekend at a family gathering. Many of my relatives are doctors, scientists, and professors. The topic of alien life came up, and almost all of them laughed it off! Now I'm merely a computer programmer so I didn't say much, but when I hear about there being hundreds of exoplants out there in space I can't help but think that there may be life on at least some of them. After all, these are only the planets that we know about so far! There are probably millions upon millions of other similar planets out there that we just haven't discovered yet.

    Why do well-educated scientists consider alien life, even if it's very simple or nothing like life here on earth, to be such an absurd idea? Why do they have so much trouble considering it with any seriousness?

  • by JoshuaZ ( 1134087 ) on Sunday November 20, 2011 @07:36PM (#38119744) Homepage

    That's not really good reason to believe they don't exist. A galactic spanning civilization, for one, would only be visible, as you say, across the galaxy.

    That's not obviously the case. Largescale stellar engineering is something we might notice. Dyson Spheres and Ringworlds for example are both things that we'd be able to see in nearby galaxies. Similar remarks apply to other big engineering projects.

    But anyway, I agree that it's likely that microbial life of various sorts is abundant. And on the other end, I've always felt that it is only a kind of cellular chauvinism that prevents us from thinking of stellar objects as life forms. They grow, they mantain homeostasis, they sometimes reproduce in a fashion, they consume, they die.

    By this logic fire would be alive also. Stars don't seem to do much of the things that life does, in particular, stars don't reproduce in a way that makes stars more similar to themselves than not so (except in so far as high metal content supernova lead to even higher metalicity).

  • weird (Score:4, Interesting)

    by khipu ( 2511498 ) on Sunday November 20, 2011 @07:39PM (#38119754)

    The more planets and potentially earth-like planets we discover, the more paradoxical the Fermi paradox becomes: "where are they?"

  • by PPH ( 736903 ) on Sunday November 20, 2011 @08:14PM (#38119956)

    We can restate the original premise. Our methods are biased towards finding large planets close to stars.

    Given the limits of our current techniques, it should be possible to quantify the limits of their resolution. Put this together with some models of solar system formation and we can extrapolate our observations using a model that says X% of all planetary discs tend to evolve into systems with large planets that migrate in toward their sun. So 1-X remain in some other state. perhaps one we can't detect (yet).

  • by wisebabo ( 638845 ) on Sunday November 20, 2011 @08:37PM (#38120060) Journal

    Look, my friends said it is very very likely not that it was 100% sure (they are scientists after all!). I mean that's a very reasonable stance to take considering that there are about a 100 billion stars in our galaxy, and about a trillion stars in the OBSERVABLE universe (the actual universe is likely to be MUCH larger, maybe infinite). Considering the large proportion of stars that seem to have planets and the billions of years they've been around it, doesn't it seem very VERY likely that life would have started more than once?

    Flip a coin several trillion times. What's the chance that it won't come up heads more than once?

    Of course I've read "Rare Earth" AND his other book "Life, But not as we know it" in which he says life could've arisen not just on earth but on Mars, Europa, Enceladus and maybe THREE TIMES on Titan! So while he is (rightfully) concerned that COMPLEX life is "rare" (but not impossible) he also seems to think that (simple) alien life is present almost everywhere!

    Also, my chemist friend is in the geological sciences dept. of his university and works with experts in the fields of extremeophiles. As for the others, please realize that science is not a vacuum, at least not at the level that they practice it and they follow major developments in other fields both directly and indirectly; they, to varying degrees, have an excellent idea as to what's going on. (My computational linguist friend probably knows the details of the transit studies, he's the kind of guy who learned a difficult Asian language on his spare time while raising a couple kids while developing algorithms so sophisticated he has to give the state dept. one month advance notice before leaving the country).

    Actually I'm beginning to think that the people who claim that their educated brethren say that we are unique have their own, belief based, agenda to push. Whatever.

  • by gronofer ( 838299 ) on Sunday November 20, 2011 @08:38PM (#38120064)
    It's also possible that numerous civilisations with a similar level of technology to ours exist, but it's simply impossible in practice to "colonise the galazy". Inter-stellar travel may simply require too much energy/resources, or it may turn out to be infeasible to survive in space for long enough for anybody to reach another star.
  • by Anonymous Coward on Monday November 21, 2011 @01:43AM (#38121422)

    If you believe the geological models of the rise of life on Earth, I find it very telling that life came about so rapidly.

    3.8 billion years ago, the earth was probably still molten rock.

    Sometime after that, water started to condense on the surface.

    3.5 billion years ago, we find fossils for single cellular life. The surface temperature was still high, there was still much exposed molten lava, the day was only 15 hours, radiation blasted the surface incessantly... but life existed in only the first 0.5% of the wet Earth's lifespan.

    The odds of life being extraordinarily unique on Earth, yet popping up within the first 0.5% of the time that there was water on the surface leads me to believe that life is almost inevitable when given the right circumstances.

    That really lends more credence to the idea that it might eventually happen elsewhere.

    Now, complex life... no idea. There's no way to know how rare that actually is.

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