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NASA Finds Family of Habitable Planets

Posted by samzenpus on from the welcome-to-the-neighborhood dept.

coondoggie writes "NASA's star-gazing space telescope continues to find amazing proof that there are tons of habitable planets in space and we have only scratched the surface of what's out there. The space agency said today its Kepler space telescope spotted what it called its first Earth-size planet candidates and its first candidates in what it considers to be the habitable zone, a region where liquid water could exist on a planet's surface. Kepler also found six confirmed planets orbiting a sun-like star, Kepler-11. This is the largest group of transiting planets orbiting a single star yet discovered outside our solar system."

17 of 184 comments (clear)

  1. Re:Overlords by aBaldrich · · Score: 3, Funny

    There's only one of me

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    In soviet russia the government regulates the companies.
  2. Okay, hold on a minute. by 2muchcoffeeman · · Score: 4, Insightful

    Can we call them "potentially habitable planets" instead of going all the way to "habitable" that quickly? I think I'd like to make sure of certain things before being so definite -- for instance: water, temperature, oxygen levels, lack of poisonous gases making the oxygen-level issue moot, edible flora and/or fauna, radiation levels ... hmmm, could be here awhile ...

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    1. Re:Okay, hold on a minute. by Anonymous Coward · · Score: 3, Funny

      Right... because if they had edible flora... oh wait! *face palm*

    2. Re:Okay, hold on a minute. by Rinnon · · Score: 3, Funny

      Can we call them "potentially habitable planets" instead of going all the way to "habitable" that quickly? I think I'd like to make sure of certain things before being so definite -- for instance: water, temperature, oxygen levels, lack of poisonous gases making the oxygen-level issue moot, edible flora and/or fauna, radiation levels ... hmmm, could be here awhile ...

      I don't see how that would help Nasa get more funding.

    3. Re:Okay, hold on a minute. by sznupi · · Score: 4, Informative

      It is borderline good as far as its orbit is concerned (indeed, maybe it even had oceans of water few billion years ago, perhaps even some biosphere). And for some time, we'll know only the orbits of Kepler planets / that's why some of them are considered to be in the habitable zone.

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    4. Re:Okay, hold on a minute. by BenSchuarmer · · Score: 3, Informative

      Actually, these planets were discovered because they transit between their star and us (not by the star wobbling).

      I would be surprised if they were habitable, given that they're all less that .5 AU from their star (which is 95% as big as the sun). See: http://en.wikipedia.org/wiki/Kepler-11

    5. Re:Okay, hold on a minute. by sznupi · · Score: 3, Informative

      It's not about magnetic field. What exactly happened to Venus isn't quite clear of course, but one of more likely hypotheses is that Venus was too small to sustain plate tectonics (Earth might be borderline) - which could help with a runaway greenhouse effect.

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      One that hath name thou can not otter
    6. Re:Okay, hold on a minute. by babtras · · Score: 5, Interesting

      I suppose the Earth being potentially borderline habitable may have something to do with the apparent lack of evidence of extraterrestrials. A planet that is too friendly to life may not have had the 6+ mass extinctions and rapidly changing environment that helps drive evolution. One that's borderline habitable like ours (assuming the assertion in your link is true) keeping life for as long as it has might be a tremendous fluke.

    7. Re:Okay, hold on a minute. by ravenspear · · Score: 5, Informative

      It's not that hard to understand.

      If you can observe a planet with a few different methods, you can reliably calculate it's mass and radius from the size it appears, it's orbital period and inclination, the effect it exerts on the star, and other data points.

      Once you have the mass and radius, you can calculate the density, which allows you to speculate on whether it is rocky or gaseous. This in turn opens up other informed analyses of the conditions that might be present given it's distance to the star and other factors.

      It's atmospheric composition can also be determined with spectroscopy.

      If you really think astronomers are just guessing, you couldn't be more wrong. It's true that there is a lot that we don't know about these planets, but what we do is built on a solid mathematical foundation.

    8. Re:Okay, hold on a minute. by sznupi · · Score: 5, Interesting

      It's not for a lack of trying... Generally, "habitable" and "promoting complex life" are probably two different things (for one, comfortably habitable (by the criteria from my link) planets might be, from certain point on, way too active for stable complex ecosystems). And "promoting intelligence" - another thing. "Leading to technological civilization" - yet another. That might be enough of an explanation. We're here for a blink of an eye, so far.

      --
      One that hath name thou can not otter
    9. Re:Okay, hold on a minute. by nofx_3 · · Score: 3, Funny

      We've known about hydrocarbon seas on Titan for a couple years now and we have yet to invade...

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    10. Re:Okay, hold on a minute. by Daniel+Dvorkin · · Score: 3, Informative

      Hold up ... I've never heard anyone claim that it's the magnetic field which keeps hydrogen from escaping. AFAIK it's simple gravity which keeps our atmosphere in place. Given a large enough planetary body, I'm having a hard time imagining hydrogen atoms reaching escaping velocity, regardless of what kind of radiation they're being bombarded with. You got a source for that?

      This is pretty well known. Here is one reference of many: "Our neighboring planet, Mars, which has little or no magnetic field, is thought to have lost much of its former oceans and atmosphere to space. This loss was caused, at least in part, by the direct impact of the solar wind on Mars' upper atmosphere. Our other close planetary neighbor, Venus, has no appreciable magnetic field, either. Venus is also thought to have lost nearly all of its water to space, in large part owing to solar wind-powered ablation."

      --
      The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
    11. Re:Okay, hold on a minute. by bertok · · Score: 3, Insightful

      Another example, the people telling us the world's weather is going to be a specific number of degrees hotter or colder in a decade. They can't even accuratly predict a week out.

      Your ignorance of the scientific process doesn't invalidate it.

      The example you mentioned is a straw man argument based on ignorance. There's a huge difference between climate and weather prediction. The former is like trying to predict the temperature at which a pot of water will boil, the latter is like predicting the location on the surface of the water where the steam bubbles will appear. One of those is predictable and depends on simple thermodynamics that is well understood, the other is full of randomness and uncertainty, and is difficult to predict far into the future.

      Either way, none of that has anything to do with astronomy, which is about as precise, non-random, and rigorous as any science gets. The measurements these guys are making are just simple intensity measurements over time. There's no need to develop hugely complex models with trillions of unknowns and interacting nonlinear feedbacks and systems that require supercomputers to solve to a useful level of precision. The equations astronomers work with can be solved on the back of a napkin.

      To give you an idea of the kind of precision that astronomers are used to working with, the Gaia Mission will create a star catalogue with position measurements as accurate as 20 microarcseconds. If you think of that as a fraction of a circle, that is 15 parts per trillion! The Kepler spacecraft has a rather pedestrian precision of only 20 parts per million, which is still orders of magnitude better than what any climatologist has ever had to work with.

      On top of that, this mission is not making a prediction about the future, but making a straightforward measurement that can be trivially verified later. There's no uncertainty to speak of.

  3. Selection effects by Michael+Woodhams · · Score: 5, Informative

    Surveys such as this tend to find lots of large planets close to their stars. It is worth pointing out that this is at least partly because such planets are easier to detect, and does not necessarily mean they are a high proportion of planets in the galaxy.

    Kepler detects changes in stellar brightness due to transiting planets. The closer a planet is to its star, the less precise the alignment has to be for us to observe a transit. Also, the closer it is, the faster it orbits, and the more likely we observe a transit in the limited time we're observing that star. This second factor will become less restrictive as the Kepler mission runs for a longer time. (I presume they need at least two, possibly more, transits before they claim a detection.) Large planets will also give a larger, easier to detect change in brightness.

    The other major way of detecting planets is spectroscopically: the planet wobbles the star slightly, and we observe the Doppler shift. This favours massive planets (they wobble the star more) and close planets (they wobble the star faster.)

    There have I think also been a few cases where clever interferometry has allowed direct imaging of extrasolar planets. I don't know what the selection effects on this are - further away means easier to separate from the star (good) but less bright (bad.)

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  4. The article != the actual NASA press release by Noren · · Score: 5, Informative

    It's not NASA's fault, the actual press release says nothing of the sort.

    The NASA press release described a system of at least 6 larger -than-earth planets, all much closer to their sun than Earth is. Late in the release, they mention that "Kepler will continue conducting science operations until at least November 2012, searching for planets as small as Earth, including those that orbit stars in the habitable zone, where liquid water could exist on the surface of the planet. Since transits of planets in the habitable zone of solar-like stars occur about once a year and require three transits for verification, it is predicted to take at least three years to locate and verify an Earth-size planet. "

    Then Michael Cooney appears to have invented from whole cloth the title, "NASA Kepler finds family of habitable, Earth-size planets". I do have to admit that the Slashdot title is pretty close to the Cooney source, but the article is... not even close to what it claims to be its source material.

  5. Re:Overlords by dkleinsc · · Score: 4, Funny

    There were 10, but I just got an instruction saying "Spawn more overlords!"

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  6. Great!! So..... by blankoboy · · Score: 4, Insightful

    can we stop killing each other and focus on space exploration now? For all you corporate types: I am sure there are plenty of diamonds, gold, oil and other fantastic elements on these planets.