Scientists Release Biggest 2D Map of the Universe

The DESI Legacy Imaging Surveys team unveiled a 5.6-trillion-pixel 2D map of the universe, the largest ever created, featuring nearly 4 billion stars and galaxies. The data, accessible through the Legacy Survey Sky Viewer, enables researchers and citizen scientists to explore celestial phenomena such as gravitational lenses, supernovae, and the distribution of dark matter and dark energy. The map builds on earlier versions and has already contributed to over 1,800 published scientific papers. "It’s part of the fabric of astronomy research now," said David Schlegel of Lawrence Berkeley National Laboratory.

The updated map covers 75% of the sky in visible and near-infrared light, offering a deep view of the extragalactic universe unobstructed by the Milky Way. It was compiled from 263,407 telescope exposures across three ground-based surveys and supplemented by data from NASA’s WISE satellite. More than 160 scientists contributed to the project, with a team of 20 producing the final dataset. Arjun Dey of NSF NOIRLab noted the survey’s potential to aid investigations into the universe’s expansion and galaxy formation.

Originally designed to support the Dark Energy Spectroscopic Instrument (DESI) survey, the 2D map serves as a deep photographic record of the sky, identifying galaxy and star locations and brightness. This data guides DESI’s selection of objects for further spectral analysis, contributing to the construction of the largest high-resolution 3D map of the universe. Early DESI results suggest dark energy’s influence may be weakening over time, a finding that could reshape understanding of the universe’s fate.

The new Legacy Surveys map has been used to select DESI targets since June 2026 and will inform telescope operations in the coming years. Processing the data required significant computational effort at Berkeley Lab’s Perlmutter supercomputer. The map will also serve as a reference for future telescopes like the Vera C. Rubin Observatory and NASA’s Nancy Grace Roman Space Telescope, and support AI-driven analysis of astronomical data.