Largest 2D Map of the Universe Completed After 13 Years

After 13 years of observation, the DESI Legacy Imaging Surveys have produced the largest 2D map of the Universe ever created, covering three-quarters of the sky and cataloging nearly four billion celestial objects. The map was assembled from 263,407 photographs taken by the NSF Mayall and Blanco telescopes, the latter equipped with the 570-megapixel Dark Energy Camera. The resulting 5.6-trillion-pixel image includes stars, galaxies, black holes, and asteroids, and is now publicly available. Over 160 scientists contributed to the project, which has already been referenced in more than 1,800 scientific papers. The survey was originally designed to support the Dark Energy Spectroscopic Instrument (DESI) survey, which completed its mission ahead of schedule in April, mapping over 47 million galaxies and quasars. The new 2D map will serve as a foundational reference for future observatories like the Vera C. Rubin Observatory. According to David Schlegel, co-lead of the Legacy Surveys, the map has become 'part of the fabric of astronomy research.' Arjun Dey, NSF NOIRLab astronomer and co-lead, emphasized that 'the skies belong to everyone,' making the survey accessible for all to explore.