More than a trillion pixels from a million-plus images, combined to create the most detailed map of the universe ever created—one that would require a wall of a half-million HDTVs to properly appreciate. Not bad for something that looks a little like tan carpeting.
What you’re seeing is about one-third of the sky, imaged by the Sloan Digital Sky Survey, which has been assembling images from Apache Point Observatory in New Mexico for more than a dozen years to image the cosmos in unprecedented detail.
It replaces an image that is now over half a century old, created on photographic plates by the Palomar Sky Survey in the 1950s but still used by astronomers today. It contains 10 times as many objects – such as galaxies, stars and nebulae – as the Palomar survey and scientists hope it will be used for decades to come by astronomers hunting for everything from dark matter to planets orbiting other stars. [The Guardian]
At Sloan’s website you can blow up some of the sample images, but even those large files pale in comparison with the sheer mass of data packed into these maps of the universe. With so much detail, the Sloan Survey could become an invaluable reference point for astronomers seeking just about anything.
It is now focusing on measuring the light spectra of objects seen in the huge image. One project within the survey aims to measure spectra for more than a million galaxies. These spectra reveal how far away the galaxies are, and by measuring so many of them, astronomers will create the biggest 3D map of the universe yet. Analysing the map will allow them to probe the nature of the mysterious dark energy that is thought to be accelerating the expansion of space. [New Scientist]
The density of galaxies, nebulae, and other objects glimpsed by Sloan is also why the image appears to glow in orange fire at the outermost view. Zoom in to the scale of individual objects and the emptiness of space becomes more apparent. For example, check out the top part of the image above, in which the picture is zoomed to the scale of a galaxy and then further zoomed in on a small, star-birthing region inside it.
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Image: Sloan Digital Sky Survey