1 Milky Way; 3,000 Images

What a gorgeous and immense image! And it’s full of stars! An astronomer from Central Michigan University has put together a new high-resolution panoramic image of the full night sky , with the Milky Way galaxy as its centerpiece. Axel Mellinger stitched together over 3,000 images to create this beautiful image, which also comes in an interactive version, showing stars 1,000 times fainter than the human eye can see, as well as hundreds of galaxies, star clusters and nebulae.

View an interactive version at Mellinger’s website.

Mellinger spent 22 months and traveled over 26,000 miles to take digital photographs at dark sky locations in South Africa, Texas and Michigan. After the photographs were taken, “the real work started,” Mellinger said.

Simply cutting and pasting the images together into one big picture would not work. Each photograph is a two-dimensional projection of the celestial sphere. As such, each one contains distortions, in much the same way that flat maps of the round Earth are distorted. In order for the images to fit together seamlessly, those distortions had to be accounted for. To do that, Mellinger used a mathematical modelโ€”and hundreds of hours in front of a computer.

Another problem Mellinger had to deal with was the differing background light in each photograph.

“Due to artificial light pollution, natural air glow, as well as sunlight scattered by dust in our solar system, it is virtually impossible to take a wide-field astronomical photograph that has a perfectly uniform background,” Mellinger said.

To fix this, Mellinger used data from the Pioneer 10 and 11 space probes. The data allowed him to distinguish star light from unwanted background light. He could then edit out the varying background light in each photograph. That way they would fit together without looking patchy.

The result is an image of our home galaxy that no star-gazer could ever see from a single spot on earth. Mellinger plans to make the giant 648 megapixel image available to planetariums around the world.

Source: EurekAlert

13 Replies to “1 Milky Way; 3,000 Images”

  1. The new Mellinger mosaic was discussed – and compared to a ‘competing’ giant mosaic promoted by ESO – by me some time ago. Turns out that Mellinger’s has the higher true resolution and color depth, the other one has only even more pixels because it’s somewhat oversampled.

  2. I’m not understanding the use of the term “megapixels” here. Are we talking about “648 megapixels?” Or, are we talking about “megabytes?” I have been looking for an upgrade to my 14 megapixel camera!

  3. I appreciate the huge amount of work that has gone into both the Mellinger and Brunier (ESO) mosaics.

    It is a shame, however, that neither image is available publicly at full resolution. Both men follow the policy of photographers (as opposed to professional astronomers) and insist on license fees for their data.

    Ironically, this means that the best all-sky image publicly available is the IRAS infrared image, not one in visible light!

    It would be great if someone funded a publicly available full sky image at a decent resolution.

    Of course, there is the DSS, but it lacks the calibration of the full sky images.

    Kevin Jardine
    Galaxy Map


  4. @ astronary
    I’m not understanding the use of the term ‘megapixels’ here. Are we talking about ‘648 megapixels?’ Or, are we talking about ‘megabytes?’

    Its talking about 648 mega pixels. Not megabytes. If you go to the website of the other mosaic, you would have learned the lower resolution rival had a size of about 32 gigabytes.

    However I prefer the other one, for reasons of presentation, they got a streaming screen server of theirs. Which caused my bandwidth to overload the limit during the night. >_<… was great while it lasted.

  5. The Fermi Gamma ray ST is looking to be a smashing success. It appears that more evidence for dark matter is coming in for the center of the galaxy.



    Draft โ€” October 26, 2009

    Preprint typeset using LATEX style emulateapj v. 03/07/07



    Gregory Dobler,1,2,5 Douglas P. Finkbeiner,1,3 Ilias Cholis,4
    Tracy Slatyer,1,3 & Neal Weiner4

    Draft โ€” October 26, 2009


    The Fermi Gamma-Ray Space Telescope reveals a diffuse inverse Compton signal in the inner Galaxy with the same spatial morphology as the microwave haze observed by WMAP, confirming the synchrotron origin of the microwaves. Using spatial templates, we regress out _0 gammas, as well as ICS and bremsstrahlung components associated with known soft-synchrotron counterparts. We find a significant gamma-ray excess towards the Galactic center with a spectrum that is significantly harder than other sky components and is most consistent with ICS from a hard population of electrons. The morphology and spectrum are consistent with it being the ICS counterpart to the electrons which generate the microwave haze seen at WMAP frequencies. In addition to confirming that the microwave haze is indeed synchrotron, the distinct spatial morphology and very hard spectrum of the ICS are evidence that the electrons responsible for the microwave and gamma-ray haze originate from a harder source than supernova shocks. We describe the full sky Fermi maps used in this analysis and make them available for download.

  6. @LBC, I came across the ‘Fermi haze’ paper recently at the arXiv preprint page and was fascinated by the new work presented using data from Fermi. This is good news indeed for those studying DM and its distribution. Off topic, but on a related note, another recent paper entitled “High Energy Electron Signals from Dark Matter Annihilation in the Sun” describes a simple test using Fermi to look for DM in good old Sol. The short paper can be found here: http://arxiv.org/PS_cache/arxiv/pdf/0910/0910.1839v1.pdf . Great to see more observational clues and testable predictions of DM finally coming into their own. Maybe UT could do a story on this exciting development ๐Ÿ™‚

    @kevinjardine, Many thanks for the links you provided in your previous post. I’ll be spending some time checking out both, especially the Galaxy Map site. I, too, lament the inability to access full-res versions of these mosaics (for free) and hope some sort of arrangements may become available for the general public to peruse these detailed all-sky mosaics. I have noticed that the ESA Hubble site sometimes offer full-res color mosaics of objects (usually derived from the DSS) that range in size from 400-600MB TIFF files. Perhaps their servers could also accommodate some of these huge all-sky mosaics.

  7. The authors are cautious about projecting this as due to dark matter. However, these inverse Compton scattered photons are due to some high energy process similar to what one might expect for neutralino decay/annihilations.


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