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Space Science

Alpha Centauri Has an Earth-Sized Planet 152

Posted by Soulskill
from the i-wonder-if-they-have-oil dept.
The Bad Astronomer writes "Astronomers have announced that the nearest star system in the sky — Alpha Centauri — has an Earth-sized planet orbiting one of its stars. Alpha Cen is technically a three-star system: a binary composed of two stars very much like the Sun, orbited by a third, a red dwarf, much farther out. Using the Doppler technique (looking for very small changes in the velocities of the stars) astronomers detected a planet orbiting the smaller of the two stars in the binary, Alpha Centauri B. The planet has a mass only 1.13 times that of the Earth, making it one of the smallest yet detected.However, it orbits the star only 6 million kilometers out, so it's far too hot to be habitable. The signal from the planet is extremely weak but solidly detected (PDF), giving astronomers even greater hope of being able to find an Earth-like planet orbiting a star in its habitable zone."
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Alpha Centauri Has an Earth-Sized Planet

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  • by Anonymous Coward

    Let's use that as a setting for a sci fi movie and waste it on contortionist zombies and scientists who act like complete douchebag morons. Awesome.

    • by jamstar7 (694492) on Tuesday October 16, 2012 @08:18PM (#41676251)

      Let's use that as a setting for a sci fi movie and waste it on contortionist zombies and scientists who act like complete douchebag morons. Awesome.

      Seriously, dood, you gotta stop writing for SyFy Channel.

      • Let's use that as a setting for a sci fi movie and waste it on contortionist zombies and scientists who act like complete douchebag morons. Awesome.

        Did you have a hand in Prometheus?!

      • by pellik (193063) on Tuesday October 16, 2012 @10:24PM (#41677345)

        Let's use that as a setting for a sci fi movie and waste it on contortionist zombies and scientists who act like complete douchebag morons. Awesome.

        Seriously, dood, you gotta stop writing for SyFy Channel.

        I don't get it. What does his comment have to do with wrestling?

        • by flex941 (521675)
          There are some "Zombie Originals" too on the channel from time to time when wrestlers rest.
    • by MachDelta (704883) on Tuesday October 16, 2012 @08:18PM (#41676255)

      Sounds good. Let's call it... Chiron. Or maybe Manifold 6?
      Ooh, ooh, is it going to have telepathic worms?

      • Re: (Score:2, Funny)

        by Anonymous Coward

        We should send seven leaders, who can't agree on anything, on a spaceship to go visit and check the place out.

  • by Anonymous Coward

    We already know that Zefram Cochrane is going there sometime in the next century to retire and live out his life with a cloud being... probably Apple's iCloud

  • Dear /S/cientists (Score:5, Interesting)

    by DSS11Q13 (1853164) on Tuesday October 16, 2012 @08:08PM (#41676151)

    how do planets orbit binary star systems? I would think two stars would give the planets erratic orbits that would either send them into one of the suns or shoot them into space.

    • Re:Dear /S/cientists (Score:5, Informative)

      by bjorniac (836863) on Tuesday October 16, 2012 @08:31PM (#41676347)

      It's rather the same way the moon orbits the earth. If you have a binary system, a planet can quite happily orbit very close to one of the two stars so long as the distance between the planet and the star it orbits is smaller than the distance between stars. The pair of stars will orbit their mutual center of mass, and the planet will orbit a single star.

      Of course, the three body problem is an open question in physics, but if you make the assumption that one of the masses is much smaller than the other two it (which is the case for planets orbiting stars) it becomes quite solvable, especially if you're happy with numerical simulations of orbits.

      A similar situation is possible if the planet is a long way from the pair of stars, and would then orbit their center of mass. That isn't the case here, but is certainly a feasible solution to the problem. You only really get orbits that are highly erratic when the planets orbital radius is over a quarter of the distance between the stars.

      Throughout this I've assumed equal mass stars. Feel free to put a factor of M1/M2 in front of every distance I gave for non-equal mass stars.

      • As a follow up to your input, would it be possible for a planet to have a figure 8 orbit around a binary star system? i.e. the planet has such a highly elliptical orbit that it goes part way around one star but is then sent off on a trajectory which allows it to be "captured" by the second star but is again flung out on a reverse trajectory to be "captured" by the first star?

        Just a thought question.

        • by bjorniac (836863)

          A figure-8 is quite hard to find, since the symmetries involved would require almost perfectly equal masses between the stars and perfectly circular orbits of the stars. (This is from memory running simulations a long while back). However it is certainly possible to have a planet be orbiting one star for a few loops and then be captured by the other, orbit it a few times and keep getting passed back and forth.

          The basic condition you need for this is for the planet to have enough energy to get over the maxim

    • Re:Dear /S/cientists (Score:4, Informative)

      by MyLongNickName (822545) on Tuesday October 16, 2012 @08:56PM (#41676579) Journal

      Not an erratic orbit at all. Picture Jupiter. If it suddenly increased its mass by a factor of 20, it might have enough mass to become a star, but would have virtually no impact on the orbit of Mercury, and very little on Earth or Venus. Just because a body becomes a star does not require planets to orbit both stars. In actuality, all planets orbit the center of mass of the solar system. In our solar system's case that resides inside the sphere of our sun.

    • There have been a number of planets found orbiting binary star systems. Kepler has identified a planet around a star in a binary pair, orbited much further out by another binary pair.
    • by sFurbo (1361249)
      Either very close to one star (as in this case), so it is, in effect, orbiting one star, of vary far from the star, so it is orbiting the center of mass. I think both could be unstable, but so could any three-body problem, and that hasn't stopped our solar system from existing.
    • All bodies in all solar systems orbit a common centre of gravity - which is not necessarily even within the central star. As planetary systems go, those in binary systems orbit the barycentre of the stellar system, unless they orbit too close to either of the stars in which case it becomes a Lorentzian body, which then orbits both stars in a semi-chaotic orbit describing a figure-8 of varying distance from both stars, with both stars becoming orbital axes.

      • Even the moons?
        • the Earth/Moon system shares a common barycentre which lies somewhat off the centre of Earth's core - in effect, both bodies orbit a point in space rather than the Moon orbiting Earth.

  • If somehow we "made contact" with some "ET" type, and they had the means to get here "quickly", you think they would come in friendship? LOL, probably blow us up like the Klingons, Borg or some other crap. Just leave things alone will ya?
    • by MyLongNickName (822545) on Tuesday October 16, 2012 @09:34PM (#41676891) Journal

      Why is this modded down? Stephen Hawking [neatorama.com] would agree.

    • Re: (Score:2, Insightful)

      by sakari (194257)

      If somehow we "made contact" with some "ET" type, and they had the means to get here "quickly", you think they would come
      in friendship? LOL, probably blow us up like the Klingons, Borg or some other crap. Just leave things alone will ya?

      That's what the television and movies tell you, don't they? Do you ever wonder why most of them tell that ETs are here to attack us ?
      To keep us in Fear and to believe that if someone would come here, this would be automatically justify a reason for us to attack them.

      Think about how the US & Hollywood portrays terrorists in movies, TV -series and mainstream news. Same thing with Extraterrestrial Life.

      Oh, and btw. Imagine, that if there are civilizations out there who are _exponentially_ more evolved, hav

      • by mcgrew (92797) *

        Our society has suppressed this information for so long to keep us blinded from the truth. The communication happens telepathically and during meditative states of mind, or during dreams.

        WTF, slashdot? That's insightful??? Prove telepathy exists, prove that the "telepathic" subject actually had contact, prove it wasn't a stupid dream, do it with the scientific method and you could have a point. But you see, you can no more prove that than you can prove that sentience exists.

        This was NOT the least bit insigh

  • ... considering that if the distance estimate is right, its orbit is 1/10 that of Mercury. Better put on the SPF 1million if you go out on that rock.
    • If it's that close, it's likely tidally locked, or at least have a very slow rotation as does Mercury; so, the "dark side" should stay icy.
      • by NeMon'ess (160583) *

        Exactly. What is the temperature on the side away from the sun? I'm guessing the atmosphere has been blown away by stellar wind. If not the convection could make it a furnace anyway.

  • by Gort65 (1464371) on Tuesday October 16, 2012 @08:28PM (#41676321)
    ...for us about some space bypass or something. Seems important for some reason.
  • Temperature = 1500K (Score:4, Informative)

    by kf6auf (719514) on Tuesday October 16, 2012 @08:29PM (#41676333)

    That sounds really cool. Or hot since, unfortunately, the close proximity to its star means that it probably has a surface temperature of 1500 K.

    I guess I'd be more interested in a different-sized planet a bit further away from its star.

    • by harperska (1376103) on Tuesday October 16, 2012 @11:45PM (#41677847)

      What makes this a big deal, is that prior to this it was an open question whether the Alpha Centauri system could support planets orbiting the individual stars or not. Now that it has been shown that planets can orbit the individual stars in this system, as opposed to orbiting outside both stars around the common center of gravity as is the case for most planets in binary systems, the probability of their being more planets including possible ones in the habitable zones of the stars just got a whole lot bigger.

    • by v.dog (1093949)
      Then they really are the real small furry creatures.
    • by IrquiM (471313)
      That's only ~1227C - that's not even enough to melt Manganese
  • When can we start travelling over there?

    We have to establish colonies with factions fighting each other! [gog.com]

  • Unfortunately the United States can't even get off the planet anymore, and musicians out bid the USA for seats on the Russian rocket.
    • Re:Unfortunately (Score:5, Informative)

      by murdocj (543661) on Tuesday October 16, 2012 @09:02PM (#41676623)

      Not unfortunate, just a recognition of reality. At this moment in time, the science return for sending unmanned probes / orbiters / rovers vastly exceeds the return on sending humans. We'll continue to develop space capability and at some point it may make sense to send humans to Mars ... or maybe not.

      And please do NOT invoke the whole "omg we have to get off this rock" argument. If an asteroid impact blew most of Earth's atmosphere and water into space and annihilated 99.999% of the species, Earth would STILL be easier to live on than Mars.

    • Unfortunately the United States can't even get off the planet anymore...

      Sure we can. [wikipedia.org]

      • by Mad Marlin (96929)

        I really think the reason we have such stalled space progress is because of NASA. I don't mean to go all libertarian, but I do think that NASA suffers from a lot of the worst problems of any large governmental body, and that has suffocated space research.

  • Using the Doppler technique (looking for very small changes in the velocities of the stars) astronomers detected a planet orbiting the smaller of the two stars in the binary

    I understand how the Doppler effect actually works, I don't understand how it works on a scale of this magnitude, with one or two sources of reference and data that has been determined "scrubbable" (as in, "static noise", or data that doesn't belong in the analysis). How exactly is the speculation even tied to something worth a story?
    • by tp1024 (2409684)

      > How exactly is the speculation even tied to something worth a story?

      It is tied to something worth a story by a scientific paper linked in the fucking article.

  • by viperidaenz (2515578) on Tuesday October 16, 2012 @09:59PM (#41677147)
    A very close and very fast orbit produces weak but detectable movements of its star. But what if the planet were moving much slower and was much further away? Would that not mean the star would move even less, and slower as well? How does this give more hope to detecting planets in the habitable zone? Its 25x closer to its star than Earth. It's also 13% heavier than Earth and Alpha Centauri B is 9% lighter than the Sun. If my napkin calculations are correct, this planet has ~700x more gravitational effect on its star than Earth has on ours.
    • by RockDoctor (15477)
      Well done, you've realised the basic difficulties of using the Doppler method for small planets in (relatively) distant orbits.

      But the techniques are getting better. And the "transit" method (OGLE, Kepler projects) has different constraints.

  • by BlackGriffen (521856) on Tuesday October 16, 2012 @10:22PM (#41677329)

    "it's far too hot to be habitable."

    That's an understatement. From the ArsTechnica article on the alpha Centauri planet [arstechnica.com]:

    "But don't start building the colony ship just yet. With a 3.3 day orbit, the planet is only 0.04 Astronomical Units (1 AU is the typical distance from the Earth to the Sun). That makes this planet blazingly hot, at about 1,500 Kelvin."

    • by Anonymous Coward

      If calling 1,500 kelvins "far too hot to be habitable" is the understatement of the year, then I'll call it merely "too hot to be habitable" and win the award!

  • by Nyrath the nearly wi (517243) on Tuesday October 16, 2012 @10:32PM (#41677395) Homepage

    Space bloggers (like me) who are signed up with the ESO news feed got word of this overnight. But the story was under embargo. You do not break the story until the embargo lifts or the ESO and Nature magazine gets very angry at you.

    But some loud-mouth in Croatia violated the embargo. We were patiently waiting for the embargo to lift, biting our collective tongues, when mouthy jumped the gun.

    We got an email from the ESO about an hour ago that said:

    "I just spoke to the Head of Press at Nature, Ruth Francis, and we have agreed to LIFT THE EMBARGO on the Alpha Cen story IMMEDIATELY due to an unfortunate leak. You may run your stories."

    Nature and ESO lift exoplanet embargo early following coverage by Croatian news outlet [wordpress.com]

  • Here come the baby elephants [wikipedia.org].
  • by crunchygranola (1954152) on Tuesday October 16, 2012 @11:20PM (#41677709)

    It is entirely possible that there are undiscovered planets in the habitable zone. It is the planets closest to the star with the shortest orbital periods that are the easiest to discover, either because generate frequent perturbations that can be detected in the data set, or are the most likely to cross the stellar disk (when using the brightness fluctuation method).

    • by Shavano (2541114)

      It is entirely possible that there are undiscovered planets in the habitable zone. It is the planets closest to the star with the shortest orbital periods that are the easiest to discover, either because generate frequent perturbations that can be detected in the data set, or are the most likely to cross the stellar disk (when using the brightness fluctuation method).

      Then sign me up! If there's a star in the habitable zone, we'll colonize it when we get there. If there's not, we should have advanced enough technology by that time to move the planet we've already discovered anywhere we want it.

      • If there's not, we should have advanced enough technology by that time to move the planet we've already discovered anywhere we want it.

        Yeah, but they've been saying planet-moving technology is five years away since the 60s.

      • by RockDoctor (15477)
        You want to colonize a star. Fine. Go ahead. Don't forget to leave the mike on "transmit" as you land, I'd like a soundtrack for the nursery.
  • We no longer need to develop the not-quite-impossible-anymore warp drive. Just wait to buy jump gate technology from our good and dear friends.
  • - the orbital period is way longer (let's say 1 year) ... so I guess you'd need at least 1 year and then some of observation data (albeit with a lower sample rate) to make sure you really found something and it's not a fluke.
    - this is even worse if you go for observing passes of the planet in front of it's host star (as the possibility of the pass from our perspective decreases with distance, and also the time between passes increases).

  • Ah! Home sweet home, I do miss it sometimes but the journey back is a pain in the ass.

  • by Rexdude (747457) on Wednesday October 17, 2012 @05:26AM (#41679215)

    We're stuck here for good, destined to just keep looking at extra solar planets via telescope and speculating about whether they could support life as we know it. The nearest star, Proxima Centauri, is 4.3 light years away. The farthest man made object is just roughly 17 light hours [twitter.com] from home after 35 years of travel; so forget about sending spaceships physically to the stars unless someone invents warp drive. It's laughable to talk of Alpha Centauri when no one in power is showing interest in returning to the moon, let alone Mars.
    And leaving aside that, we're stuck with the reality of NASA facing budget cuts despite its overall budget being a drop in the ocean compared to what's been spent on war in the last 10 years.
    Space exploration should've been incremental, start with a lunar refuelling base at the pole where there's water ice that can be broken down into hydrogen and oxygen for rocket fuel, and use that as a staging area for further exploration. Build a spacecraft for travelling to Mars in LEO stage by stage, and send a bunch of robots to assemble a modular base well before the first humans are sent (Kim Stanley Robinson's Mars series describes this approach).

    While Curiosity, Opportunity & Spirit are testimony to NASA's engineering prowess, it still can't beat an actual geologist (areologist?) on Mars with a field laboratory who's able to directly analyse rocks and figure out what it was like in the past.

    Want some perspective? Just the annual airconditioning budget for the US Army in Iraq/Afghanistan far exceeds [npr.org] that of NASA's.

    • by ledow (319597)

      Let's be honest - Voyager was never intended to be a transport to get to Alpha Centuri. It's designed to be a low-power "poodle-along" slowcoach to get to the outer planets, not to get much further, and to take it slow because it takes DAYS to send back an image that it's captured and anything faster moving wouldn't provide enough useful data.

      The problems of scaling up and speeding up aren't insurmountable but are HUGE, I grant you. But considering that 51 years ago no man had ever gone into space whatsoe

  • Especially Rann. Now, *where* did I put my red flight suit and rocket packs?

                      mark "Alanna's waiting for me...."

  • Quick, gather seven intelligent, ruthless leaders with widely disparate ideologies and barely restrained hostility toward each other, then put them on course for the planet.

"Your mother was a hamster, and your father smelt of elderberrys!" -- Monty Python and the Holy Grail

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