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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 ZankerH ( 1401751 ) on Sunday November 20, 2011 @06:48PM (#38119528)
    Because if what we've found so far is at least a somewhat representative sample, the overwhelming majority of planets tend to be either gas giants, frozen balls of rock and ice, or roasted balls of rock and lava. You have to be terribly imaginative to see life coming up on worlds like that.

    Of course, even if we go by 1 in 700, or 1 in a million for that matter, the Milky way ought to be positively teeming with life. We simply don't have enough data to make a meaningful conclusion either way yet.
  • by chebucto ( 992517 ) on Sunday November 20, 2011 @07:00PM (#38119588) Homepage

    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?

    The scientists in your family may not be representative of scientists in general.

    I've always assumed that most people who know the numbers involved think that alien life must exist (with a hundred billion stars per galaxy and hundred billion galaxies, it seem like there are pretty good odds).

    Whether we'll communicate with, travel to, or be visited by aliens is an entirely different question with a lot more scope for doubt.

  • by 0123456 ( 636235 ) on Sunday November 20, 2011 @07:04PM (#38119608)

    I've always assumed that most people who know the numbers involved think that alien life must exist (with a hundred billion stars per galaxy and hundred billion galaxies, it seem like there are pretty good odds).

    Part of the problem is that some people use 'alien life' to mean anything from microbe-sized upwards while others use it to mean 'little grey men in flying saucers'. The former is almost certain to exist, but there's no evidence for the latter and good reason to believe that they don't exist; technology merely a few thousand years ahead of ours should be visible across much of the galaxy.

  • by Ragondux ( 2034126 ) on Sunday November 20, 2011 @07:15PM (#38119652)

    But we know that what we've found so far is NOT a representative sample, because the methods are biasied towards finding jupiter-sized planets?

  • by xigxag ( 167441 ) on Sunday November 20, 2011 @07:22PM (#38119678)

    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. Not across the entire universe. And secondly, as of right now it is only a pipe dream that a couple thousand more years of history will spread us across the stars. We might just as easily blow ourselves up, retreat into a cyber-singularity, or just run out of gas, so to speak.

    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 NoobixCube ( 1133473 ) on Sunday November 20, 2011 @07:56PM (#38119846) Journal

    How would we see a Dyson Sphere if it's capturing all the output from their star? It would be just another patch of blackness against the inky black of space. Our small slice of space we can view at any given time is very tiny, frequently changing, and we can't actually see most of these exoplanets, just their effect causing their stars to wobble. We'd have no hope of seeing satellites around a planet, or space shuttles, or even a space ship the size of one of the Alliance citadel style things in Firefly, with current technology, unless they were within the inner solar system, or buzzed a probe in the outer system. We might see something very large if it deliberately silhouetted itself against Jupiter, for us.

  • by syousef ( 465911 ) on Sunday November 20, 2011 @11:20PM (#38120800) Journal

    Gas giants can't form close to stars, they have to migrate towards them.

    That too is in question. To understand why we see so many Jupiter-sized planets you really need to understand the techniques we use to detect them. []

    For some methods fully confirming a planet requires more than one orbit. Their orbit may be measured in years, decades or centuries. For other methods it's a one off event and we can't confirm the existence of the planet. The first confirmed planets were detected around a pulsar (a kind of dead star) only in 1992. And the method used only worked for pulsars. It took until 1995 to detect a planet around a main sequence star. []

    Then it took years to get dedicated space instruments up. Effectively we've been at this only for 17 years. Given the difficulty that's nothing. Give it time! Perhaps your grandkids will grow up with earth sized planets confirmed.

  • Re:weird (Score:4, Insightful)

    by SuiteSisterMary ( 123932 ) <slebrun AT gmail DOT com> on Monday November 21, 2011 @08:47AM (#38122894) Journal

    I've always found the Fermi Paradox amusing.

    Imagine a large city. Imagine within this city, a smaller city, in a dome which is visually opaque, but completely open to all other electromagnetic spectra.

    Plop a scientist from, say, the 1800s into that domed city. Ask him to prove the existance of life outside the dome based on communications. Is he going to be able to intercept and decode NTSC? ATSC? 802.11b/g/n? CDMA? GSM? Hell, AM and FM?

I was playing poker the other night... with Tarot cards. I got a full house and 4 people died. -- Steven Wright