Largest 3D Map of the Universe Completed by DESI to Study Dark Energy

The Dark Energy Spectroscopic Instrument (DESI) has completed its celestial survey, producing the largest-ever high-resolution 3D map of the universe. The map spans 11 billion years of cosmic history and includes over 47 million galaxies and quasars, plus 20 million stars. DESI finished on April 15, ahead of schedule, after starting data collection in May 2021. Originally aiming for 34 million galaxies and quasars over five years, it exceeded expectations. The instrument, attached to the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory in Arizona, uses 5,000 fiber-optic 'eyes' scanning the sky every 20 minutes, generating 80 gigabytes of data per night. Early observations suggest dark energy may be weakening, challenging previous assumptions. The international collaboration involves over 900 researchers from more than 70 institutions, managed by the Department of Energy's Lawrence Berkeley National Laboratory. DESI will continue mapping into 2028, focusing on difficult-to-observe regions near the Milky Way's plane.