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Kepler: Many Red Dwarfs Have Earth-SIzed Planets Too

Posted by Unknown on from the prepare-for-invasion dept.

astroengine writes "Extrapolating from findings by NASA's planet-hunting Kepler Space Telescope, scientists on Wednesday said roughly six percent of so-called red dwarf stars have Earth-sized planets properly positioned around their parent stars so that liquid water could exist on their surfaces. The team looked at 95 candidate planets circling red dwarf stars observed by Kepler and found that at least 60 percent have planets smaller than Neptune. Most were not the right size or temperature to be Earth-like, but three were found to be both warm and approximately Earth-sized. Statistically that would mean six percent of all red dwarf stars should have a Earth-sized planet. Since 75 percent of the closest stars are red dwarfs, the nearest Earth-like world may be just 13 light-years away."

33 of 132 comments (clear)

  1. 14 LY from earth? by Anonymous Coward · · Score: 4, Interesting

    Not to nerd out but wouldn't that make it Vulcan?

    1. Re:14 LY from earth? by luxifr · · Score: 3, Informative

      Vulcan is supposed to be in the 40-Eridani-System, which is about 16LY away from us and it's a trinary system. But scientists think that it may host a habitable planet :)

      So not all is lost ^^

    2. Re:14 LY from earth? by mcgrew · · Score: 3, Interesting

      Vulcan circles a red dwarf? Wikipedia says nothing about the planet or its star, just about the Vulcans themselves. I was thinking Krypton, even though I haven't read a Superman comic since I was 7 or 8; it orbits a red star.

      I'm always amused by "only n light years away" in every story about a newly-found planet. Adams was right. "Space is big. I mean really big. You think it's a long way to the chemist..." the Voyagers have been traveling for 40 years and still haven't gotten past the heliopause. Even Adams was understating the vast distances between stars, try as he might to impress how big space is. Getting to Vulcan/Krypton is indeed infinitely improbable, at least for the next few hundred years and maybe never.

      Depressing, isn't it?

      --
      Free Martian Whores!
    3. Re:14 LY from earth? by Lithdren · · Score: 2

      To be fair, there was a time where travel to China from the UK was considered impossibly far, taking months of time assuming you didn't get killed along the way.

      Then there was the giant, impassible ocean that went so far over the horizion we were pretty sure it was the edge of the world.

      Humans have this funny way of looking at something, going "Oh geez, yeah forget that!" and end up passing it off as common place some years later. I suspect humans will someday explore the stars, if we dont kill ourselves off first. The only thing that can stand in our way is ourselves.

    4. Re:14 LY from earth? by whitroth · · Score: 2

      Nope. Darkover.

                mark

    5. Re:14 LY from earth? by Unknown+Lamer · · Score: 2

      Well, if an inhabited planet were only 15 or 30 light years away... there's a chance for some form of communication... a "hey we're a technological society" beacon at least. Having any evidence of another technological civilization in our neighborhood would be incredible, and might even inspire humanity to do things like colonize the solar system.

      --

      HAL 7000, fewer features than the HAL 9000, but just as homicidal!
    6. Re:14 LY from earth? by BeanThere · · Score: 2

      Some thoughts for consideration:

      - Within 50 years (if not much sooner), we'll almost certainly have cured aging. Once humans regularly live in the many hundreds (or even thousands) of years, a 20, 30, 50, even 100 year trip won't seem as long (plus we'll have great on-board entertainment to keep us busy thanks to advanced robotic girlfriends).

      - Once you approach even half the speed of light, local time slows down for you, so e.g. a 50 year trip would be 'only' 30 or 40 years (I haven't done the exact math)

      - Accelerating humans to half C won't be easy, but if you consider that aging may be cured in our lifetimes, the goal of sending autonomous robotic explorers to stars (a la Mars Curiosity) just 13ly away may be quite feasible in some of our lifetimes. That alone is exciting. If you live 500 years, and you send a robotic probe at 1/10th C to a star 13 ly away (130 year trip plus 13 years for data to come back), you'll EASILY live to see the results. And beyond that, who knows - the technology of 150 years from now, we may well be sending the first humans to the nearest stars by then.

      This is not even 'inane fantasy', it's just what is likely to become possible, and even to become mundane reality.

      My suspicion is that we'll never find a way to travel faster than the speed of light. But our discussions seem to be limited by a common inability to imagine that other variables, that we take for granted, may change dramatically - e.g. the typical human lifespan.

      Also, perspective: We've been 'human' for approximately 2 million years. We have millions of years ahead of us as a species, and even on cosmic scales, you can do an enormous amount in even just 2 million years.

      I'm cautiously optimistic. I think our future in space is practically certain, and that we'll probably ultimately reach hundreds of other stars, and establish colonies on other planets. It's a matter of when and how, not if. The only thing that can stop us if everyone collectively gives up. That isn't going to happen, there will always be humans who want to explore.

    7. Re:14 LY from earth? by dotancohen · · Score: 2

      Bet-al-Geuse: The house of Geuse.

      The armpit is called "the house of the shoulder" in Semetic languages, so "house of Geuse" could be understood as "armpit of Geuse". Actually, the "Bet" is thought to be a misreading of "Yad" (very similar letters in Arabic) and the name was originally "Yad al Jauza" or the "hand of Jauza". I've yet to discover who Jauza is / was but I still do have some resources to check, just not the time!

      If you or your lecturer are interested in any other star names, you can contact me. My Gmail username is the same as my /. username. In fact, I'm leaving later today for a ten day vacation to the arctic circle to see the northern nights for the first time, so you'll have to wait for an answer!

      --
      It is dangerous to be right when the government is wrong.
    8. Re:14 LY from earth? by rioki · · Score: 2

      Actually, as I understand it, the speed of light is quite well understood. Nothing with mass can travel faster than the speed of light because the energy required approaches infinity the closer you get to C. But that does not mean we cant build a "faster then light" drive, by sidestepping the actual movement. Just look at the Alcubierre drive, sure we can't muster the energy, figure out that little strange matter problem and may actually sterilize the destination, but FTL is not totally impossible. It may not happen in the next few centuries, but we have an entire solar system to explore fist, so no stress.

    9. Re:14 LY from earth? by Intrepid+imaginaut · · Score: 2

      Unless I'm mistaken the math is straightforward; at C the trip would seem instantaneous to the traveler, so half C a 50 light year trip would seem like 25.

      No, there aren't really noticeable relativistic effects until you get into the .8C region or thereabouts, and the effects don't become significant until you go much faster.

  2. Nice thing about red dwarf stars by PvtVoid · · Score: 4, Interesting

    One attractive feature of red dwarf stars, it would seem to me, is that they have much longer lifetimes than sun-like stars. More time for complex life to evolve!

    1. Re:Nice thing about red dwarf stars by K.+S.+Kyosuke · · Score: 5, Interesting

      One attractive feature of red dwarf stars, it would seem to me, is that they have much longer lifetimes than sun-like stars. More time for complex life to evolve!

      On the other hand, being (necessarily, due to temperature issues) much closer to their star, these planets are likely to be tidally locked, which is *not* a good thing for complex life trying to evolve.

      --
      Ezekiel 23:20
    2. Re:Nice thing about red dwarf stars by arcctgx · · Score: 3, Insightful

      On the other hand, such stars have deeper convection zones which makes their magnetic dynamos much stronger than in the Sun. The resulting magnetic activity may manifest itself in very strong flares. If the magnetic field of the planet is not strong enough, such phenomena could adversely affect the evolution of complex life forms.

    3. Re:Nice thing about red dwarf stars by PvtVoid · · Score: 2

      Wouldn't those flares also make for large variations in radiative output? Imagine what would happen to us if Sun suddenly decided to increase (or decrease) its output by 50 percent for a few weeks or months.

      Apparently, yes: see arXiv.1111.2872.

    4. Re:Nice thing about red dwarf stars by rgbatduke · · Score: 3, Informative

      A tidally locked planet would have all of its atmosphere period precipitated out on the dark side. There would be no habitable band. The antipode opposite the sun would be open to space, cooling the surface there, essentially 100% of the time. There would be no factors driving global circulation -- the atmosphere would rapidly stratify (and get very hot indeed, stably, on the side facing the sun). Eventually, where by eventually I mean in a matter of a few days if one stopped the Earth from rotating without vaporizing it (can't be done, sure, I know) it get cold enough to first rain, then snow, the snow carbon dioxide, then the greenhouse effect disappears and the temperature really plummets, and in just a little bit more time you have a rain of oxygen and nitrogen followed (as they deplete the atmosphere by a fall of solid oxygen-nitrogen sleet). As fast as it falls out on the dark side, it is replenished from the warm side (cooling as it comes) until the warm side -- now bloody hot not unlike the lit side of the moon -- has almost no atmosphere at all. The dark side has a rather large mountain of frozen air centered fairly symmetrically on the solar antipode. There would probably be some residual partial pressure of gas, but it wouldn't be enough to keep your blood from boiling anywhere on the planet's surface.

      If the atmosphere was a more exotic mix, you'd actually precipitate out the gases in layers, frozen methane in one layer, oxygen in another, hydrogen and helium on top of the whole mess at the end.

      So "tidally locked" is indeed a fatal problem.

      --
      Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
    5. Re:Nice thing about red dwarf stars by atrain728 · · Score: 3, Funny

      Oh and I'm wrong.

    6. Re:Nice thing about red dwarf stars by Dasher42 · · Score: 4, Insightful

      What about moons orbiting gas giants in the habitable zone of red dwarves - any reason to pass that up?

    7. Re:Nice thing about red dwarf stars by Anonymous Coward · · Score: 2, Interesting

      Tidal locking by itself is not a fatal problem. For example, it has been estimated that if Earth were tidally locked, the night side temperature would be fairly frosty bottoming out at -33 C but that's nowhere near cold enough to cause the atmosphere to freeze out. An atmosphere anywhere above 10% of Earth's is sufficient to transfer heat to the night side. Water ice accumulation would not be a problem either, since the oceans would be free to flow underneath an ice sheet.

      However, tidal heating could be a problem for such a close orbit. Planetary orbits don't start out near-perfectly circular, there's a period of time during which the orbit of a planet is eccentric. This induces a strongly variable tidal force that will heat up the planet and burn off any volatiles like water. You would have to introduce water (e.g. by comet impacts) after the orbit has settled at low eccentricity.

    8. Re:Nice thing about red dwarf stars by ceoyoyo · · Score: 2

      I think that's probably the one I was thinking of. The patterns might be a bit different for something in the habitable zone, but tide locked is still going to mean windy. Venus, for example, isn't tide locked but it does rotate very slowly. Winds on Venus reach 700 km/h.

      The winds might diminish as you approach the point directly under the sun (or the one directly opposite). They might be eyes of giant, perpetual hurricanes. But most of the planet would be very windy.

    9. Re:Nice thing about red dwarf stars by HiThere · · Score: 3, Interesting

      That was the old theory. Currently, IIUC, it is only believed to apply if there is no atmosphere. If there is an atmosphere, its circulation redistributes the heat...though slowly enough that there is, indeed, a huge difference in temperatures between the day side and the night side. Naturally, exact details depend on the composition of the atmosphere. (If Venus were tidally locked, it wouldn't change much of anything.)

      --

      I think we've pushed this "anyone can grow up to be president" thing too far.
    10. Re:Nice thing about red dwarf stars by mpthompson · · Score: 2

      On the other hand, being (necessarily, due to temperature issues) much closer to their star, these planets are likely to be tidally locked, which is *not* a good thing for complex life trying to evolve.

      Larger gas planets in the habital zone could have Titan/Mars size moons that may be tidally locked to their parent planet, but have an apparent "day" with respect to the parent star on the order of 48 to 200 hours long. Given that we believe there are many more moons than planets in any given system, it seems that moons would likely to be where the interesting biological action may be occurring.

  3. Um... by Anonymous Coward · · Score: 2

    I'm not sure that is a large enough sample size to say, 6% is an accurate number. Perhaps they are over reaching? Just a little.

    1. Re:Um... by Anonymous Coward · · Score: 2, Interesting

      The summary is a bit difficult to interpret. For example, it seems like they're reporting percentages only considering red dwarf stars with planets, and then extrapolating to red dwarf stars (undetermined with/without planets). Perhaps this explains how they got a 6% estimate when 3/95 is much closer to 3%. With a 3/95 proportion of "earth-like planets" to "no earth-like planets" the 95% confidence interval for the probability of having an "earth-like" planet around a red dwarf (with planets?) is 0.66% to 8.95%. The only way to actually determine the closest "earth-like" planet orbiting a red dwarf would be to actually examine each red dwarf in order of nearness. Statistics always have uncertainties, and it would be awesome if those uncertainties were reported along with the "most likely" or "best guess" at the true value. I suppose it's too confusing for most.

      In case you want to play with the confidence intervals:
      http://statpages.org/confint.html

  4. Now he has a planet, too? by fyngyrz · · Score: 4, Funny

    Many Red Dwarfs Have Earth-SIzed Planets Too

    Are we talking about Korea's leader again?

    --
    I've fallen off your lawn, and I can't get up.
  5. The only problem with this by dkleinsc · · Score: 2

    So let's say you travel those 14 light-years, and get there to find that some holographic guy named Arnold J Rimmer has been exiled there for being a complete smeghead. I mean, that's worse than merely a wasted trip!

    --
    I am officially gone from /. Long live http://www.soylentnews.com/
    1. Re:The only problem with this by jellomizer · · Score: 2

      But this sounds like rather interesting quest.
      Smoke me a kipper, I'll be home for breakfast.

      --
      If something is so important that you feel the need to post it on the internet... It probably isn't that important.
  6. The problem with Red Dwarf planets... by SailorSpork · · Score: 4, Funny

    ...is that its cold outside, and there's no kind of atmosphere. You're all alone, more or less.

    1. Re:The problem with Red Dwarf planets... by tom17 · · Score: 3, Funny

      Well from what I understand, the reddish colour will result in goldfish shoals nibbling at your toes too.

      But there is also fresh mango juice on offer, so there is that if it helps.

  7. Just 13 Light Years by avandesande · · Score: 2

    Just 13 Light Years LOL!

    --
    love is just extroverted narcissism
    1. Re:Just 13 Light Years by forestgomp · · Score: 2

      That's 14 years of travel at 0.5g constant-acceleration
      http://en.wikipedia.org/wiki/Space_travel_using_constant_acceleration#Interstellar_traveling_speeds
      Just don't hit anything....

  8. I thought Red Dwarfs only had by Virtucon · · Score: 2

    Lister, Kryten, the Cat and Holly?

    --
    Harrison's Postulate - "For every action there is an equal and opposite criticism"
  9. Earth-sized... by BlueTak · · Score: 2

    Why couldn't life exist on a bigger planet. Well I know that gravity would be stronger but in water, gravity means little. Is my question stupid ?

    1. Re:Earth-sized... by BeanThere · · Score: 2

      FWIW, some additional info:

      Life possible on extrasolar moons "In their search for habitable worlds, astronomers have started to consider exomoons, or those likely orbiting planets outside the solar system. In a new study, a pair of researchers has found that exomoons are just as likely to support life as exoplanets."

      Just keep in mind this field is an interesting area of active research. So take things with a grain of salt. But we have huge amounts of interesting new data coming from a.o. the Kepler observatory, and other projects. E.g.:

      At Least One in Six Stars Has an Earth-Sized Planet, Analysis Finds "A new analysis of Kepler data shows that about 17 percent of stars have an Earth-sized planet in an orbit closer than Mercury. Since the Milky Way has about 100 billion stars, there are at least 17 billion Earth-sized worlds out there"

      Planets Abound: Astronomers Estimate That at Least 100 Billion Planets Populate the Galaxy "There's at least 100 billion planets in the galaxy -- just our galaxy,"

      Fifteen New Planets Hint at 'Traffic Jam' of Moons in Habitable Zone "Added to the 19 similar planets already discovered in habitable zones, where the temperature is neither too hot nor too cold for liquid water, the new finds suggest that there may be a 'traffic jam' of all kinds of strange worlds in regions that could potentially support life."