Astronomers have released the largest two-dimensional map of the universe ever created, offering a sweeping new view of nearly 4 billion celestial objects across roughly 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 an enormous portrait of stars, galaxies and other cosmic phenomena across the sky, according to a statement from the National Science Foundation (NSF) NOIRLab. (You can explore the full data here.)
“It’s part of the fabric of astronomy research now,” David Schlegel, co-lead of the Legacy Surveys and a scientist at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, said in the statement. “When you’re working with astronomical objects today, you often start by pulling up 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 Nicholas U. Mayall 4-meter 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 been 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.
DESI began its main survey in 2021 with the goal of tracing how the universe has expanded over billions of years and, in turn, helping scientists better understand dark energy, the mysterious phenomenon thought to be driving that expansion.
The project has since far surpassed its original targets. By 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 may evolve over time rather than remain constant, as predicted by the standard model of cosmology.
DESI isn’t the only project finding new ways to map the cosmos. Earlier this year, astronomers with the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) created a different kind of 3D map using faint Lyman-alpha emission from hydrogen between galaxies. That effort illuminated previously hidden structures dating to between 9 billion and 11 billion years ago, when the universe was experiencing a peak in star formation.
The new Legacy Imaging Surveys map, meanwhile, will have uses well beyond DESI. Previous versions of the dataset have already been referenced in more than 1,800 scientific papers, while the latest release could help astronomers search for rare objects and phenomena, study galaxy evolution and train artificial intelligence systems to analyze the enormous volumes of data expected from next-generation observatories.
“Explorations of our universe always start with images of the night sky. The DESI Imaging Legacy Surveys are just one step in this venerable human tradition,” Arjun Dey, co-lead of the Legacy Imaging Surveys and an astronomer at NSF NOIRLab, said in the statement. “For our team, these data are fundamental to the investigation of the expansion history of the universe and the formation of our galaxy. But the skies belong to everyone, and this survey gives everyone the chance to marvel at their wonders.”
