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Space Science

150 Gigapixel Sky Image Contains 1 Billion Stars 126

Posted by Unknown Lamer
from the scientists-declare-universe-contains-lots-of-stuff dept.
The Bad Astronomer writes "Astronomers have used two big telescopes to create an infrared survey of the Milky Way that is the largest of its kind: the resulting image has an incredible 150,000 megapixels containing over a billion stars. Something that large is difficult to use, so they also made a pan-and-zoom version online which should keep you occupied for quite some time. These data will be used to better understand star formation in our Milky Way, and how far more distant galaxies and quasars behave." The interactive image is powered by IIPImage which happens to be Free Software and is cool in its own right (right click the image to get help — it has a full set of keybindings for navigation).
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150 Gigapixel Sky Image Contains 1 Billion Stars

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  • Oh my god (Score:5, Funny)

    by Anonymous Coward on Wednesday April 04, 2012 @10:18AM (#39571921)

    It's full of stars!

    • Re:Oh my god (Score:4, Insightful)

      by Joce640k (829181) on Wednesday April 04, 2012 @10:34AM (#39572139) Homepage

      Question is ... is it an American 'billion' or the same 'billion' as the rest of the world?

      • Re: (Score:1, Troll)

        People raise this kind of thing a lot when they want to be pedants but in reality "a billion" now is 10^9, regardless of where you are. The Americanisation of English could be viewed as sad - and often I think it is - but that's life.

        • by Anonymous Coward

          Interestingly, the word "billion" in french stands for 10^12 (10^9 is called a "milliard"). This tends to provoke all sorts of confusion for french students learning english (and, I imagine, the reverse as well).

          • Re:Oh my god (Score:4, Informative)

            by boristhespider (1678416) on Wednesday April 04, 2012 @10:47AM (#39572313)

            the word "billion" in british english means 10^12 to a lot of people too - hence the comment i replied to. before i went into science it meant 10^12 to me, as well, but spend long enough in science and you begin to see just how few people are aware of that - and it seems to get fewer each year.

            • Re:Oh my god (Score:4, Insightful)

              by X0563511 (793323) on Wednesday April 04, 2012 @11:21AM (#39572727) Homepage Journal

              It would be nice if people would stop being stupid and we could actually say 10^12 in a news article and not get slack-jawed stares. That would solve a lot of this silly ambiguity.

              • Haha that would certainly be good. Until then we can all agree to use "a thousand millions" and "a million millions". The sheer irritation of typing all of that out - assuming that journalists won't add some key binding to automate it - will trigger a drive to ensure people know what 10^9 and 10^12 mean. Then we can slowly push them towards 10^{12}, which lets us type 10^121x without ambiguity. A few years down the road we could all be happily writing and reading LaTeX in news articles and do our bit agains

                • by mZHg (2035814)

                  Or maybe use SI prefix: kilo, mega, giga, tera, peta, etc :)
                  http://en.wikipedia.org/wiki/SI_prefix [wikipedia.org]

                  • Yeah but then you get people playing games like using megaseconds to measure a year. (A year is very approximately 30*pi megaseconds, if you don't mind shitty approximations.)

                    • Yeah but then you get people playing games like using megaseconds to measure a year.

                      I have some medicine whose dosage is "1000 mg".

                      (A year is very approximately 30*pi megaseconds, if you don't mind shitty approximations.)

                      Ah, I always wondered why people say "year round".

                    • by Joce640k (829181)

                      Yeah but then you get people playing games like using megaseconds to measure a year. (A year is very approximately 30*pi megaseconds, if you don't mind shitty approximations.)

                      And pi seconds is one nanocentury...

                    • "1000 mg" makes sense if the number of significant digits is important (which it would be in medicinal dosages). Alternatively they could write it as 1.000 g, but 1000mg is easier to read and compare with smaller doses, such as 500mg.

                    • Yes, I don't know why I wrote 30 pi instead of 10 pi. Idiocy, most likely.

                • by jc42 (318812)

                  ... Then we can slowly push them towards 10^{12}, which lets us type 10^121x without ambiguity. A few years down the road we could all be happily writing and reading LaTeX in news articles and do our bit against the dumbing-down of the internet...

                  Well, lotsa luck with that plan. I'd guess that, for the mass media, it'll always be understood that any number with more than 3 digits (or any non-digit chars) will baffle 90% of their readers. So the editors with rewrite them in words that aren't well defined, but don't scare the huge majority of their readers.

                  Of course, this is /., so we can probably reduce that 90% to 80%. ;-)

                  (And WTF does "quintillion" mean, anyway? What standards body defines such terms? No, dictionaries aren't standards bod

            • Re:Oh my god (Score:5, Insightful)

              by tlhIngan (30335) <[ten.frow] [ta] [todhsals]> on Wednesday April 04, 2012 @11:38AM (#39572937)

              the word "billion" in british english means 10^12 to a lot of people too - hence the comment i replied to. before i went into science it meant 10^12 to me, as well, but spend long enough in science and you begin to see just how few people are aware of that - and it seems to get fewer each year.

              Or a little thinking (not too much) can realize that a million-million makes no sense in this context.

              1-million-million is 1,000,000,000,000 (10^12).

              This image is 150,000-million, or 150,000,000,000.

              If 1 billion referred to was defined as million-million, it's easy to see that there would be more stars than pixels in the image by over 6 stars to 1 pixel.

              OTOH, using it as meaning 10^9, it means there's 1 star for ever 150 pixels, which seems to make MUCH more sense.

              • There is this, as well, but it involves taking the extra few seconds or so to estimate whether the number seems reasonable. Though I have to say that the controversy makes me wonder if there are millions of people in Britain who think that their national debt (£900bn or thereabouts) is a thousand times worse than it is, given that the British media - universally, so far as I've noticed - describe such large debts in "billions" (10^9) and "trillions" (10^12).

            • by aiken_d (127097)

              ...and it's just inconvenient, not having a word for 10^9. "Six hundred fifty three thousand million" is incredibly awkward to parse. At least, for an American.

            • by expatriot (903070)

              http://oxforddictionaries.com/words/how-many-is-a-billion [oxforddictionaries.com]

              In British English, a billion used to be equivalent to a million million (i.e. 1,000,000,000,000), while in American English it has always equated to a thousand million (i.e. 1,000,000,000). British English has now adopted the American figure, though, so that a billion equals a thousand million in both varieties of English.

              The same sort of change has taken place with the meaning of trillion. In British English, a trillion used to mean a million milli

              • In British English, a billion used to be equivalent to a million million (i.e. 1,000,000,000,000), while in American English it has always equated to a thousand million (i.e. 1,000,000,000). British English has now adopted the American figure, though, so that a billion equals a thousand million in both varieties of English.

                I bet their billionaires didn't appreciate the downgrade.

          • Re:Oh my god (Score:4, Insightful)

            by UnknowingFool (672806) on Wednesday April 04, 2012 @11:05AM (#39572535)
            [Carl Sagan voice]
            Milliards and milliards of stars.

            Doesn't have quite the same ring.

          • Interestingly, the word "billion" in french stands for 10^12 (10^9 is called a "milliard"). This tends to provoke all sorts of confusion for french students learning english (and, I imagine, the reverse as well).

            The local TV quite often mistranslates "billion" when they talk about the US national debt. :) They make the US look really bad if you don't notice the absurdity of the mistranslated number, which most of the common folk don't. Should fire those guys and hire someone who actually knows English, anyway.

            • by jc42 (318812)

              The local TV quite often mistranslates "billion" when they talk about the US national debt. :) ... Should fire those guys and hire someone who actually knows English, anyway.

              Except that English-language dictionaries don't agree on the meanings of any number words above "million". And there is no official standards body for the English language. Some other languages have such a body, notably French, but not English. And hiring people who pick one of a list of inconsistent definitions and declare it their "standard" is the process that led us to the morass that is the English-language "common speech".

              As others have pointed out, scientific/engineering/LaTeX notation is the o

      • Re:Oh my god (Score:5, Informative)

        by uigrad_2000 (398500) on Wednesday April 04, 2012 @10:53AM (#39572395) Homepage Journal

        It's written in English, so it is most likely using the short-scale (American system, as you call it). The U.S. has always used the short scale system, and the U.K. (and almost all other English speaking countries) have used it since 1974 [wikipedia.org].

        The long system is hardly used any place outside of Europe. So, this is one of the strange cases where the U.S. and the U.K. use the same system, and it's the system used by the majority of the world. In this case, it is France/Italy/Germany/Spain/Portugal/Netherlends that insist on using their own system.

        • The long system is hardly used any place outside of Europe. So, this is one of the strange cases where the U.S. and the U.K. use the same system, and it's the system used by the majority of the world. In this case, it is France/Italy/Germany/Spain/Portugal/Netherlends that insist on using their own system.

          In Norway, 10^9 is kalled a "milliard", 10^12 is a billion, and 10^18 is a trillion. While "milliard" is in common use, to avoid confusion most people use "1000 milliards" in place of billion. Trillion is strangely enough common, even though the danger of confusion is just as bad as with billion. I've also seen 10^x used regularly even in normal newspaper articles.

      • Re:Oh my god (Score:5, Informative)

        by Baloroth (2370816) on Wednesday April 04, 2012 @10:56AM (#39572437)
        If by "American" billion you mean "English" [wikipedia.org] billion, than yes. Since Slashdot is an entirely English speaking site, it is most appropriate to use the English word for 10^9... which is billion.
        • by fatphil (181876)
          Your use of the definite article implies that the word milliard doesn't exist. Which is news to me.
      • by rossdee (243626)

        Giga is 10^9 pixels, so it would have to be an american billion.(10^9) - it would be a bit hard to get a British Billion (10^12) in that size of picture.

        (and be able to count them.)
        In the British system, 10^9 is called a Milliard, and I think 1,000 british Billions is called a Billiard. (I am not sure how much a snooker would be.
        A Williard is the amount of money that the former head of Bain Capital has invested in the Cayman Islands

        Anyway are there other objects in the image besides stars? (nebulas, galaxie

        • by omnichad (1198475)

          Anyway are there other objects in the image besides stars? (nebulas, galaxies, comets, planets ...

          Yes. Now wouldn't it be great if we could share links to a coordinate and zoom level? They kind of missed one big detail to make this useful.

          • by Chakra5 (1417951)

            Yes. Now wouldn't it be great if we could share links to a coordinate and zoom level? They kind of missed one big detail to make this more useful.

            ftfy Let's give credit where it's due. That's quite a picture as is. I found it quite entertaining my self. Would be nice to have a share-able coordinate system though. perhaps you would put that together then?

        • by hawk (1151)

          This OS the difference between 150 pixels/star and .15 pixels/star (or, 7 stats/pixel . . .)

          hawk

      • by einyen (2035998)
        Since this is an "infrared survey of the Milky Way" it must be 10^9 stars since there is not 10^12 stars in The Milky Way. I think it's about 10^11 to 2*10^11 stars in the Milky Way?
    • Re:Oh my god (Score:5, Interesting)

      by jellomizer (103300) on Wednesday April 04, 2012 @10:42AM (#39572235)
      Perhaps a silly question... Why do a lot of the stars when you zoom in you get a black dot in the middle...
      I mean if they were a planet. 1. so many of them shouldn't be almost directly in the middle. 2. Those planets would be HUGE (or a rogue planet eclipsing the star (still why then are all of them in the center) So that seems unlikely.
    • by DedTV (1652495)
      I hear there's a really good restaurant out there. Right at the end.
  • That's Big! (Score:4, Interesting)

    by Hatta (162192) on Wednesday April 04, 2012 @10:20AM (#39571933) Journal

    Assuming 8 bits per pixel, a 150,000,000,000 pixel image would be 419GB.

    • by na1led (1030470)
      I'm sure they use some compression to bring the size down a bit.
      • by Hatta (162192)

        Well sure, but I didn't want to hazard a guess as to the compression ratio they got.

      • by Anonymous Coward

        The dark matter compresses extremely well...

    • Re: (Score:3, Funny)

      by Anonymous Coward

      Assuming 8 bits per pixel, a 150,000,000,000 pixel image would be 419GB.

      Your new computer math is intriguing to me and I wish to subscribe to your newsletter.

    • by Anonymous Coward

      And you thought the walk down the street to the chemists was big.

    • Re:That's Big! (Score:5, Interesting)

      by SureshotM6 (1539779) on Wednesday April 04, 2012 @10:44AM (#39572271)
      The source is a 91.6GB TIFF file. The filename on the server is in some of the CGI requests.

      -> curl -I http://djer.roe.ac.uk/vsa/vvv/v5.tif [roe.ac.uk]
      HTTP/1.1 200 OK
      Date: Wed, 04 Apr 2012 15:42:27 GMT
      Server: Apache/2.2.21 (Debian)
      Last-Modified: Sat, 24 Mar 2012 16:13:29 GMT
      ETag: "f61e88-16e808414a-4bbff6bf3ed80"
      Accept-Ranges: bytes
      Content-Type: image/tiff
      Content-Length: 98382135626
      Proxy-Connection: Keep-Alive
      Connection: Keep-Alive
    • Re:That's Big! (Score:5, Informative)

      by mikael (484) on Wednesday April 04, 2012 @10:57AM (#39572457)

      Raw CCD sensor data is usually more than 8 bits per channel (or colour filter). 16 bits per pixel is used for professional cameras, but those sensors use Bayer format for red, green and blue. Telescopes just place different colour filters over the entire sensor and correct for different levels of sensitivity.

      • by X0563511 (793323)

        Erm, would this even be a visible light camera? It would make more sense to me if this was some other spectra and is just false color.

        • by hvm2hvm (1208954)
          The summary says it's an infrared survey of the sky. So I'm guessing 16bit with an infrared filter (and obviously an infrared sensitive CCD).
          • by mikael (484)

            Just about every CCD is infra-red sensitive. That's due to the use of silicon and other elements. Even a mobile phone can create nfra-red pictures if you place a suitable filter in front of the lens (eg. Hoya H72).

            Of course, an astronomical telescope is going to have the sensor chilled down to well below 0C .

    • by digitalaudiorock (1130835) on Wednesday April 04, 2012 @11:53AM (#39573129)
      Who else is somehow expecting to get that thing in a email from one of your less tech-savvy relatives...
  • by Anonymous Coward

    It would make such a great wallpaper for my 250ft monitor.

  • 3D version? (Score:3, Funny)

    by cavok (154569) on Wednesday April 04, 2012 @10:27AM (#39572055)

    Why this is not in 3D yet?!?

    • Re:3D version? (Score:5, Insightful)

      by JTsyo (1338447) on Wednesday April 04, 2012 @10:34AM (#39572143) Journal
      Would you even be able to tell the difference between things lightyears away without having your two points of view much further apart that 2 sides of Earth orbit?
      • by Xiterion (809456)
        There are other ways to get depth information, especially in studies like this. Various techniques such as those mentioned here [wikipedia.org] can be used to fill in at least some of the missing data. Then you can provide the viewer with virtual points of view that are many light years apart to allow perceiving the galaxy in stereo. And to answer GP's question, probably because there's an immense pile of other data to sort through to get that depth information. Sadly, we don't yet have the equivalent of Kinect to give
      • by cavok (154569)

        ah.. do you mean it's already 3D but we cannot see the actual difference? :D

    • by Baloroth (2370816)
      Walk outside at night. Tada! the entire universe in 3D (ok, a little less than half of it, but still).
  • Peanuts to that. I think it's a long way down the road to the chemist's.

  • Daytime? (Score:5, Funny)

    by Anne_Nonymous (313852) on Wednesday April 04, 2012 @10:32AM (#39572113) Homepage Journal

    Now if we could just get a 150,000 megapixel image of the daytime sky, we wouldn't have to go outside at all.

    • Now if we could just get a 150,000 megapixel image of the daytime sky, we wouldn't have to go outside at all.

      You go outside? In the daytime???

  • by crow (16139) on Wednesday April 04, 2012 @10:34AM (#39572145) Homepage Journal

    What I find most surprising is that they report over a billion stars with an image containing 150 billion pixels. That's a much higher density that I would have expected.

    I guess that my intuition in such things isn't very good, which, not being an astronomer, isn't surprising.

  • by Anonymous Coward

    There are likely as many galaxies in the observable universe as there are stars in this galaxy.

  • Doughnut Stars (Score:1, Interesting)

    by Anonymous Coward

    Why do some of the stars look like they've got holes in them?
    http://djer.roe.ac.uk/fcgi-bin/iipsrv.fcgi?FIF=/data/vsa/vvv/v5.tif&CNT=1&SDS=0,90&JTL=11,86696 [roe.ac.uk]

  • by Anonymous Coward

    Does anyone know why almost all stars (it can be seen easier in big ones) have a black dot in the middle?

    • by omnichad (1198475)

      too bright. For some reason, super-white is rendered as black.

      • This is pretty typical of CMOS sensors, you can see it happen on a digital camera if you try hard enough (usually need a laser).

  • Awesome images and a great app, but it could be improved by allowing users to mark interesting features. The data set is too big for researchers to visually scan it all.
  • This remind me a older one, 'only' 5 Gpixel: http://skysurvey.org/ [skysurvey.org]
    Also with a Online viewer :)

  • A sense of scale (Score:4, Interesting)

    by adenied (120700) on Wednesday April 04, 2012 @12:13PM (#39573395)

    A billion stars seems like a lot but general consensus is that the Milky Way alone has 300 +/- 100 billion stars. So at best this is like 0.5% of the galaxy. I just read about the Baryon Oscillation Spectroscopic Survey looking at 300,000 galaxies and planning on hitting 1,000,000 eventually. The number of stars out there is truly mind blowing for us puny humans. It's really impressive if you stop to think about it.

  • Where is the arrow pointing to a star that says "You are here"?

  • A billion? - I kept counting forty-two. Then again, since it's not the whole Universe, maybe it was a only a subset like, say, two? Seriously, though, very impressive. As Adams understated, "Space is Big". Yep...
  • Why are there so many holes in the image?

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