Largest ever map of universe captures 47 million galaxies and quasars
A thin slice of the map produced by the DESI five-year survey shows galaxies and quasars above and below the plane of the Milky Way, with Earth at the centre Claire Lamman/DESI collaboration A five-year survey of the sky that has captured more than 47 million galaxies and quasars is now complete, enabling researchers to put the finishing touches on the most detailed map of the universe ever made. The data could help solve the mystery of an apparent weakening of dark energy, which threatens to upend our standard model of the cosmos. The Dark Energy Spectroscopic Instrument (DESI) at Kitt Peak National Observatory in Arizona has been scanning the sky since 2021. Researchers originally expected its survey to gather data on 34 million galaxies and quasars, but DESI surprised researchers with its efficiency. Because of the vast distances involved, some of these extremely faint galaxies have been observed from just 100 or 200 photons. David Schlegel at the Lawrence Berkeley National Laboratory in California says our previous maps of the cosmos include a total …









