Scientists Create Largest 2D Map of the Universe

According to an announcement from the National Science Foundation (NSF) NOIRLab, researchers have unveiled the most extensive two-dimensional map of the cosmos ever produced, presenting a vast new perspective of roughly 4 billion astronomical bodies spanning approximately three-fourths of the firmament.

## Building the 5.6 Trillion-Pixel Legacy Imaging Surveys Map

The new map was created by the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys team. According to NSF NOIRLab, the observations span visible and near-infrared wavelengths, providing a massive portrait of stars, galaxies, and other cosmic phenomena.

David Schlegel, co-lead of the Legacy Surveys and a scientist at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory, noted the tool’s everyday utility in research. “It’s part of the fabric of astronomy research now,” Schlegel 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.”

## Transitioning From 2D Imaging to 3D Cosmic Mapping

Initially, the Legacy Imaging Surveys were crafted to assist DESI in pinpointing locations for its numerous robotic optical fibers. This established a 2D foundation for DESI’s broader effort to map the universe in three dimensions, according to NSF NOIRLab.

Operating via the Nicholas U. Mayall 4-meter Telescope situated at the Kitt Peak National Observatory in Arizona, DESI records the spectra associated with galaxies and quasars. By determining their redshifts—how much their light stretches as the universe expands—astronomers calculate distances and transform a flat view of the sky into a 3D map. DESI began its main survey in 2021 to trace cosmic expansion and study dark energy. By April 2026, DESI had successfully cataloged upwards of 47 million quasars and galaxies, establishing the most comprehensive high-resolution three-dimensional map of the universe achieved to date.

## Comparing Modern Cosmic Mapping Projects

DESI is not the lone project expanding our view of the cosmos. Earlier this year, astronomers with the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) built a different kind of 3D map using faint Lyman-alpha emission from hydrogen between galaxies. That effort illuminated hidden structures dating to between 9 billion and 11 billion years ago, during a peak in star formation.

Meanwhile, the Legacy Imaging Surveys map will serve uses far beyond DESI. Previous versions of the dataset have appeared in more than 1,800 scientific papers. The latest release will assist researchers in searching for rare objects, studying galaxy evolution, and training artificial intelligence systems to analyze massive volumes of data 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, expressed via the official statement.

## Frequently Asked Questions

### What is the new DESI Legacy Imaging Surveys map?
It is the largest two-dimensional map of the universe ever created, containing 5.6 trillion pixels and covering nearly 4 billion celestial objects across three-quarters of the sky, according to NSF NOIRLab.

### How many telescope exposures were used to build the map?
The map combines more than 263,000 telescope exposures collected over more than a decade of observations and data processing.

### What is the purpose of the map?
While it initially served as a 2D foundation to help DESI point its robotic optical fibers for 3D mapping, the dataset is used in more than 1,800 scientific papers to study galaxy evolution, search for rare objects, and train AI systems.

### Who leads the Legacy Imaging Surveys team?
The surveys are co-led by David Schlegel of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and Arjun Dey of NSF NOIRLab.