Astronomers have released the largest two-dimensional color map of the universe ever created, containing an extraordinary 5.6 trillion pixels and nearly 4 billion stars, galaxies and other celestial objects.
Created by the DESI Legacy Imaging Surveys team, the enormous map covers about 75% of the sky in visible and near-infrared light. Even better, the entire dataset is publicly available, allowing professional astronomers, students and curious members of the public to explore the universe through the Legacy Survey Sky Viewer.
The map provides an especially detailed view of the universe beyond our own Milky Way. Scientists can use it to search for unusual objects and events, including gravitational lenses, where gravity bends and magnifies light from distant galaxies, and supernovae, the powerful explosions of dying stars.
It could also help researchers investigate two of astronomy’s greatest mysteries: dark matter, the invisible material thought to make up most of the universe’s matter, and dark energy, the mysterious phenomenon believed to be driving the accelerating expansion of the universe.
The new map combines 263,407 individual telescope exposures collected over 2,285 nights. More than 160 scientists contributed to collecting the observations, while a team of 20 researchers assembled the final dataset.
The images came from three major ground-based surveys using telescopes in Chile and Arizona. Researchers also added years of infrared observations from NASA’s Wide-field Infrared Survey Explorer, or WISE, along with other publicly available astronomical data.
Putting everything together was a major computing challenge. Different images were taken under different weather, atmospheric and telescope conditions, so scientists had to carefully combine and calibrate them.
Developing the necessary computer software took about a year. Processing the images then required around eight weeks on the powerful Perlmutter supercomputer at the National Energy Research Scientific Computing Center.
The Legacy Surveys were originally designed to support the Dark Energy Spectroscopic Instrument, or DESI.
The new 2D map works somewhat like an enormous photograph showing where stars and galaxies appear in the sky and how bright they are. DESI then studies selected galaxies in much greater detail, analyzing their light to determine how far away they are.
Combining those distances with their positions allows DESI to construct a three-dimensional map of the universe. Scientists can study how galaxies have clustered across billions of years of cosmic history, providing clues about how the universe has expanded and how dark energy may have changed.
DESI completed its original five-year observing program ahead of schedule in April 2026. Early findings have raised the intriguing possibility that the influence of dark energy may be weakening over time. If confirmed, that could significantly change scientists’ understanding of the universe and its ultimate fate. More complete results are expected in 2027, while DESI observations will continue into 2028.
The enormous new map will have uses far beyond DESI. Future observations from the Vera C. Rubin Observatory and NASA’s Nancy Grace Roman Space Telescope can be compared with this detailed record of the sky.
Scientists also plan to use the dataset to train artificial intelligence systems to analyze the immense quantities of information produced by modern telescopes.
Previous versions of the Legacy Surveys have already contributed to more than 1,800 scientific papers. With nearly 4 billion objects now mapped, the latest release gives scientists—and anyone with an internet connection—an unprecedented window into the universe.
Source: KSR.
