Largest-ever 3D map of the universe shows 47 million galaxies

The Dark Energy Spectroscopic Instrument (DESI) has produced the largest high-resolution three-dimensional map of the universe, cataloguing over 47 million galaxies and more than 20 million Milky Way stars from a five-year survey.

DESI has produced the most detailed three-dimensional map of the universe to date. The visualization captures a web-like arrangement of galaxies, filaments, clusters and voids. The instrument is mounted on the Nicholas U. Mayall 4-meter Telescope at Kitt Peak and uses 5,000 robotic fiber-optic sensors to collect light from distant objects. The survey ran for five years and recorded a larger sample than initially planned. Key findings: - The map catalogs over 47 million galaxies and more than 20 million nearby Milky Way stars. - DESI operates from the Nicholas U. Mayall 4-meter Telescope at Kitt Peak and uses 5,000 robotic fiber-optic sensors to gather spectra. - The five-year survey had aimed to sample about 34 million galaxies and quasars but ultimately detected over 47 million objects. - The data provide a three-dimensional view of the cosmic web and allow study of galaxy clustering and motion across time, reaching back roughly 11 billion years toward the epoch often called "cosmic noon." - Early DESI results have been reported as hinting that dark energy may evolve over cosmic history, a question central to understanding the universe's expansion. Summary: The map gives scientists a large, high-resolution dataset for studying how galaxies form and cluster and for probing the properties of dark energy. DESI will continue observing through 2028 to expand the map by about 20%, with first results from the full dataset anticipated in 2027. Future observations will target fainter and more distant galaxies and regions near the Milky Way and in the southern sky.