back to article Exoplanets from another galaxy spotted – take that, Kepler fatigue!

The Kepler Space Telescope has found oodles of exoplants, but now astroboffins have spotted the first exoplanets outside our galaxy. A group of astroboffins from the University of Oklahoma has become the first to demonstrate exoplanet observations in another galaxy – one that's 3.8 billion light years away, or one-third of the …

  1. redpawn Silver badge

    Planet-Coin

    If these planets could be linked to a blockchain we could trade "ownership" in these planets. New "coins" would be minted as new planets were discovered. This would provide incentive to fund astrophysics and would have a tangible basis.

    1. MyffyW Silver badge

      Re: Planet-Coin

      I've upvoted you @redpawn because I really hope you're joking, and I admire a sense of humour that is quite that dry and topical.

  2. Mark 85 Silver badge

    So if we can see them, they can see us. Be back, gotta' close the window blinds.

    1. Primus Secundus Tertius Silver badge

      @Mark 85

      No, we have not seen them. As the article says, “there is not the slightest chance of observing these planets directly”. We have inferred their existence, but as usual the headline misleads.

      The circumstances make it a one-way thing. So they have not seen us nor even the many interstellar planets in our own galaxy. Unless they are very advanced...

      1. Anonymous Coward
        Anonymous Coward

        The circumstances make it a one-way thing.

        Doesn't a gravitational lens work both ways?

    2. iron Silver badge

      No one would have believed, in the early years of the twenty-first century, that human affairs were being watched from the timeless worlds of space. No one could have dreamed that we were being scrutinised as someone with a microscope studies creatures that swarm and multiply in a drop of water. Few men even considered the possibility of life on other planets. And yet, across the gulf of space, minds immeasurably superior to ours regarded this earth with envious eyes, and slowly, and surely, they drew their plans against us...

      1. DropBear Silver badge
        Facepalm

        ..."minds immeasurably superior to ours" that nonetheless lack the basic notion of biohazard. Riiiight...

        1. Tom Chiverton 1

          biohazard's were a brand new thing hardly anyone knew of when WOTW was written. Just another case of SciFi reflecting society.

  3. Sorry that handle is already taken. Silver badge
    Headmaster

    Incoming pendant

    3.8 billion light years away, or one-third of the distance across the observable universe

    Due to the expansion of space, the observable universe is 93 billion light years across, so that's ~4% rather than a third.

    This is certainly not to detract from the impressiveness of the observation, however.

    1. Destroy All Monsters Silver badge

      Re: Incoming pendant

      > the observable universe is 93 billion light years across

      That's the unobservable universe, actually.

      1. Tomato42 Silver badge

        Re: Incoming pendant

        @Destroy All Monsters; no, actually we do not have upper limit for the unobservable universe

    2. Anonymous Coward
      Anonymous Coward

      Re: Incoming pendant

      The big question is are those billions real billions or American short billions?

    3. AntiSol

      Re: Incoming pendant

      I can out-pedant you: 93 billion is the diameter of the observable universe, not the radius. It wouldn't make sense to use the diameter when saying something like "X% across the observable universe", since you're by definition R distance from the edge - nothing observable can be further away than the radius. So 8% would be more accurate.

      Not that you're wrong, per se.

      And, as you say, still very impressive.

      The wiki has a helpful section listing common misconceptions about this.

      1. Sorry that handle is already taken. Silver badge
        Facepalm

        Re: Incoming pendant

        Muphry's Law in action.

    4. Ken Hagan Gold badge

      Re: Incoming pendant

      Isn't the observable universe going to be limited by the age of the universe? (I know about inflation, but that predates the recombination horizon so it isn't observable.)

      1. terrythetech

        Re: Incoming pendant

        I think you will find that the universe is still inflating, and getting faster, but still not as fast as the 'inflation' period of 10^-33 to 10^-32 seconds at the big bang - I think this may be what has confused you.

  4. Anonymous Coward
    Anonymous Coward

    "Unbound planet"

    I thought a planet was defined as "an astronomical body orbiting a star or stellar remnant". So would these be better called "large interstellar rocks"?

    Even so, pretty impressive to spot them at this distance. Do we even know how many of these are in our own galaxy?

    1. Simon Harris Silver badge

      Re: "Unbound planet"

      Unbound Moon sized planets...

      I wonder if they were still bound until the nuclear waste stored on the far side exploded.

      1. Claptrap314 Bronze badge

        Re: "Unbound planet"

        Not since 1999.

    2. tfb Silver badge

      Re: "Unbound planet"

      I assume trillions: there's no reason to think our galaxy or the galaxy we see these in is weird.

    3. Citizen99
      Coat

      Re: "Unbound planet"

      The scatterings from a game of Interplanetary Billiards.

  5. Pascal Monett Silver badge

    "2,000 moon-to-Jupiter sized planets for each main sequence star"

    I'm sorry, my mind has a problem processing that information. How can a star have that many orbiting bodies, and how is it possible to determine that there are that many free-wheelers in any galaxy, let alone one billions of light-years away ? My gast is well and truly flabbered.

    Oh, and there's a problem in that paragraph. If there are indeed 2000 moons & planets per main sequence star, it means that there are trillions of moons and planets, not trillions of stars. That would be recursive and likely reverse the expansion of our Universe due to the creation of infinite stars with 2000 times more stars for every Universal Processor tick. Check your Unicraft Handbook, I'm sure it's explained in there somewhere.

    1. Roj Blake Silver badge

      Re: "2,000 moon-to-Jupiter sized planets for each main sequence star"

      It says in the article that most planets are not bound to a star.

      1. TechnicalBen Silver badge
        Headmaster

        Re: Define "planet".

        Many of those could be "brown dwarfs" or "Oort cloud objects". That is, collections of matter smaller than the limit needed for gravitationally sustained fusion, and bigger than a grain of sand/dust. "Planet" is a difficult definition. :P

        1. onefang Silver badge

          Re: Define "planet".

          '"Planet" is a difficult definition. :P'

          Just ask Pluto.

  6. disgustedoftunbridgewells Silver badge

    Out of curiosity, does anybody know how far it would theoretically be possible to actually see (visually) detail of something given a large/advanced/whatever enough telescope? Ie: enough zoom to make out something as detailed as the basic shape of earths continents?

    1. terrythetech

      Unbelievably big - but to do that calculation I need to know how far away you are talking - easy on Mars say but in another solar system, even a local one, yes - big.

    2. tfb Silver badge
      Boffin

      The spatial resolution of a telescope with a diameter D and using light of wavelength l (should be lambda) for an object at distance d is given approximately by ld/D. Equivalently, if you want to resolve something of size R then you need a telescope of diameter ld/R. So, for instance if you wanted to resolve a metre on the moon (distance ~ 4E8m) in green light (wavelength ~ 5E-7m) then you need a telescope with diameter of about 200m (this is why we can't see the Apollo landing sites from Earth).

      If you wanted to resolve a thousand km (10^6m) object at Proxima Centuri (about 4.28ly or 4E16m), again in green light, you'd need a telescope with a diameter of about 20,000m (this seems too small to me: I'm worried that I've made a mistake).

  7. Bronek Kozicki Silver badge
    Facepalm

    Long time ago and in a galaxy far, far away ...

    That's no moon.

  8. tfb Silver badge
    Boffin

    Trillions of planets, not stars

    I think the article has a mistake: there are ~2000 planets for each star (not orbiting, obviously, unbound planets), and this implies trillions (~10^12) of planets, not stars, assuming the galaxy contains billions (~10^9) of stars. The Milky Way is usually assumed to contain between 100 & 400 billion stars.

  9. Mikel

    A dash of salt

    I expect this to be debunked shortly. 3.8 billion light years is just too far to see planets.

    1. Tom Chiverton 1

      Re: A dash of salt

      "I expect this to be debunked shortly. 3.8 billion light years is just too far to see planets."

      Which is why they didn't. RTFA

  10. Sysgod

    is this a real story?

    Professor X and his gorilla? Fake line energy?

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