Largest-Ever 2D Map of the Universe Released, Cataloging Four Billion Objects for Dark Energy Research

A 5.6-trillion-pixel portrait of the cosmos, requiring 13 years and 263,407 telescope exposures to assemble, has just been unveiled to the public. The DESI Legacy Imaging Surveys team has officially released the largest two-dimensional map of the universe ever created, a sprawling mosaic that captures nearly four billion celestial objects in unprecedented detail.[1][2][3]

The map covers roughly 75 percent of the night sky, peering through the obscuring dust and stars of the Milky Way to reveal the extragalactic universe in both visible and near-infrared light. It catalogs everything from nearby asteroids to distant supermassive black holes and majestic spiral galaxies like Messier 96, located 35 million light-years from Earth.[1][3]

"It's part of the fabric of astronomy research now," noted David Schlegel, co-lead of the Legacy Surveys at the Lawrence Berkeley National Laboratory. Astronomers routinely use the project's interactive Legacy Survey Sky Viewer as a starting point to identify and examine cosmic structures before pointing other, more specialized instruments at them.[1][3]

But the 2D map is not just a static photograph; it serves as the foundational blueprint for an even more ambitious project. The Dark Energy Spectroscopic Instrument (DESI), installed on the Nicholas U. Mayall 4-meter Telescope in Arizona, relies entirely on this 2D catalog to know exactly where to point its thousands of robotic optical fibers.[1][3]

While the 2D map records the angular positions and brightness of billions of objects, it does not measure their exact distance from Earth. DESI adds that crucial third dimension by measuring the redshift of the light emitted by these galaxies and quasars—calculating exactly how much their light has stretched as the universe expands.[1][4]

By April 2026, DESI had already mapped more than 47 million galaxies and quasars, completing its initial five-year survey ahead of schedule. This 3D data allows scientists to study how galaxies clustered at different stages in the universe's history, tracing the influence of dark energy over billions of years.[1][3]

The stakes for modern cosmology are immense. Early results from the DESI project have already provided intriguing hints that dark energy—the mysterious force driving the accelerating expansion of the universe—might not be a constant force as previously assumed, but could instead be evolving over time.[1]

If confirmed, a shifting dark energy would force a rewrite of the standard model of cosmology and alter our understanding of the universe's ultimate fate. The 5.6-trillion-pixel map ensures that astronomers have the precise coordinates needed to continue this investigation, while also providing a public treasure trove for citizen scientists hunting for supernovae and gravitational lenses.[1][3][4]