Overview
- The DESI collaboration reports the completion of its primary survey, producing the largest high-resolution 3D map with spectra for 47 million galaxies plus quasars.
- A 5,000-fiber robotic focal plane on the Mayall Telescope let the instrument retarget galaxies in about 30 seconds for each exposure.
- Early measurements hint that dark energy may change over time, pointing to weaker cosmic acceleration than a cosmological constant allows.
- Independent teams are processing the full dataset on separate pipelines, with a decisive dark-energy result expected in 2027.
- Observations continue through 2028 to expand the footprint to about 17,000 square degrees to cut biases from gaps near the Milky Way or low elevations.