Cosmic atlas maps 4 billion objects in the largest 2D sky survey

An international team released the largest 2D map of the universe, charting about 4 billion objects across three-quarters of the sky, using 13 years of data from the DESI Legacy Imaging Surveys and observations from the Dark Energy Camera (Blanco 4m), Mayall 4m, and Bok 2.3m telescopes, with data supplemented by WISE. The high‑resolution map spans visible and near‑infrared light and will guide future observatories, helping researchers find gravitational lenses, supernovae and dark‑matter/dark‑energy phenomena while informing projects like the Vera C. Rubin Observatory and the Nancy Grace Roman Space Telescope.