This New 10 Terapixel Image of the Night Sky Contains 1 Billion Galaxies

After 1405 nights of observation over 6 years, astronomers at three observatories have produced an image of the night sky that contains 10 trillion pixels of data and depicts over a billion galaxies. Bad Astronomy’s Phil Plait has the details.

It’s the result of the DESI Legacy Imagining Surveys, maps of the sky made by the three observatories (the Dark Energy Camera Legacy Survey, the Beijing-Arizona Sky Survey, and the Mayall z-band Legacy Survey, in combination with the orbiting WISE infrared observatory). They mapped the northern sky in seven colors, covering a third of the entire sky — 14,000 square degrees, or the equivalent area of 70,000 full Moons on the sky.

The ultimate goal is to better understand dark energy, the mysterious substance that’s accelerating the expansion of the Universe, by looking at the distribution of galaxies throughout the Universe. They’ll do that by picking tens of millions of the billion galaxies in the data and getting follow-up observations with the Dark Energy Spectroscopic Instrument (DESI), which will take spectra of those galaxies and find their distances.

Since we’ll know their positions on the sky, and their distances, this will make a 3D map of the Universe larger than any ever before.

The photo included at the top of the post is just a tiny tiny bit of the full image — you can pan and zoom the whole thing in this viewer. Be sure to zoom out in increments from the default view so as to fully appreciate just how absurdly large this image (and the universe) is.

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• Phil Plait
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