Scientists release biggest 2D map of the universe
newscenter.lbl.gov
August 21, 2026
6 min read
53/100
Summary
The DESI Legacy Imaging Surveys have released a 5.6-trillion-pixel, publicly accessible 2D color map of the universe containing nearly 4 billion celestial objects, mainly stars and galaxies. The map combines 263,407 telescope exposures from three ground-based surveys, along with NASA WISE satellite and other public data, and covers about 75% of the sky in visible and near-infrared light. More than 160 scientists contributed to data collection, while a 20-person team produced the final dataset. Processing images captured across 2,285 nights took eight weeks on the Perlmutter supercomputer at Berkeley Lab’s National Energy Research Scientific Computing Center. The map provides positions and brightness measurements that let the Dark Energy Spectroscopic Instrument select targets for distance measurements and construct a 3D map of the universe. DESI began using the updated map for target selection in June 2026. DESI completed its original five-year survey in April 2026 and continues observing through 2028; early results have indicated that dark energy’s influence may be weakening over time, according to the collaboration. The data can also support searches for gravitational lenses and supernovae, comparisons with future Rubin Observatory and Nancy Grace Roman Space Telescope observations, and AI tools trained to analyze petabytes of astronomical data.
Key Takeaways
- The DESI Legacy Imaging Surveys map contains 5.6 trillion pixels and nearly 4 billion celestial objects, making it the largest released 2D color map of the universe.
- The dataset combines 263,407 exposures from three ground-based surveys with NASA WISE satellite data and covers roughly 75% of the sky in visible and near-infrared light.
- The 2D map supplies targets for DESI, which measures galaxy distances to build a high-resolution 3D map and study dark energy over cosmic time.
- DESI completed its original five-year survey in April 2026 and plans improved first-five-year results in 2027 while continuing observations into 2028.
- Legacy Surveys data will be used to help train AI systems for analyzing petabytes of astronomical observations.
What the discussion said
The thread was almost entirely an astronomy and visualization discussion rather than an AI/ML one. Readers were struck by the map’s scale and spent time exploring the interactive viewer, with several describing the experience as humbling or unusually effective at conveying how densely galaxies fill apparent empty space. Practical curiosity centered on whether the full dataset can be downloaded, how large an uncompressed image would be, and whether the survey could be experienced more naturally in VR or as a spherical sky viewer. The most substantive exchange concerned what the 2D label actually means. Several readers initially treated it as a flat projection lacking distance, then others clarified that it represents directions across the celestial sphere rather than a claim that the universe is planar. Commenters also explained why turning every observed object into a reliable 3D placement is difficult: redshift and spectroscopy provide distance estimates, but those estimates rest on a calibration chain and are complicated by motion, lensing, imperfect brightness information, and finite data quality. A smaller side discussion speculated pessimistically about future astronomy funding, though this was political and strategic rather than tied to the survey’s scientific merits. No comments meaningfully addressed AI models, machine learning methods, or AI applications.
Where opinion split
The only real point of friction was whether calling the survey a 2D map misleadingly implies a flat universe or merely describes a sky-sphere projection. Skeptics found the label confusing because the observed universe has depth; others argued that the map records angular positions on a spherical surface, while trustworthy distance estimates require much more than simply assigning every point a third coordinate.