Astronomers have published the largest two-dimensional map of the universe ever created, offering a sweeping new view of nearly 4 billion celestial objects across about three-quarters of the sky. The new map, created by the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys team, contains a staggering 5.6 trillion pixels and combines more than 263,000 telescope exposures collected over more than a decade. The observations span visible and near-infrared wavelengths, providing a huge portrait of stars, galaxies and other cosmic phenomena in the sky, according to a release from the National Science Foundation’s (NSF) NOIRLab. (You can explore the full data here.) “It’s now part of the fabric of astronomical research,” David Schlegel, co-director of Legacy Surveys and a scientist at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, said in the release. “Today, when you work with astronomical objects, you often start by opening the Legacy Imaging Viewer to see what you’re looking at.” The latest 2D cosmic map represents the culmination of 13 years of observations and data processing. The Legacy Imaging Surveys were originally designed to help DESI determine where to point its thousands of robotic optical fibers, essentially creating the 2D foundation for DESI’s much larger effort to map the universe in three dimensions. Installed on the 4-meter Nicholas U. Mayall Telescope at Kitt Peak National Observatory in Arizona, DESI measures the spectra of galaxies and quasars. By determining their redshifts (how much their light has stretched as the universe expands), astronomers can calculate their distances and transform a flat view of the sky into a 3D map of the cosmos. You might like DESI began its major study in 2021 with the goal of tracking how the universe has expanded over billions of years and, in turn, helping scientists better understand dark energy, the mysterious phenomenon believed to drive that expansion. Since then, the project has far exceeded its original goals. As of April 2026, DESI had mapped more than 47 million galaxies and quasars, creating the largest high-resolution 3D map of the universe to date. Previous DESI results have also provided intriguing evidence that dark energy can evolve over time rather than remaining constant, as the Standard Model of cosmology predicts. Among the nearly four billion objects on the DESI Legacy Imaging Surveys map is Messier 96 (NGC 3368), a majestic spiral galaxy located in the constellation Leo, approximately 35 million light years from Earth. (Image credit: DESI Legacy Imaging Surveys/LBNL/DOE & KPNO/CTIO/NOIRLab/NSF/AURA)DESI is not the only project finding new ways to map the cosmos. Earlier this year, astronomers at the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) created a different type of 3D map using weak Lyman-alpha emission from hydrogen between galaxies. That effort illuminated previously hidden structures dating back to between 9 billion and 11 billion years ago, when the universe was experiencing a peak in star formation. Meanwhile, Legacy Imaging Surveys’ new map will have uses far beyond DESI. Previous versions of the dataset have already been referenced in more than 1,800 scientific papers, while the latest version could help astronomers search for rare objects and phenomena, study the evolution of galaxies, and train artificial intelligence systems to analyze the huge volumes of data expected from next-generation observatories. “Explorations of our universe always begin with images of the night sky. The DESI Imaging Legacy Surveys are just one step in this venerable human tradition,” Arjun Dey, co-director of Legacy Imaging Surveys, an NSF NOIRLab astronomer, said in the statement. “For our team, this data is fundamental to investigating the history of the expansion of the universe and the formation of our galaxy. But the heavens belong to everyone, and this study gives everyone the opportunity to marvel at its wonders.”
