Credit: (Credit: R. Lafever, J. Moustakas/DESI Collaboration)
The Dark Energy Spectroscopic Instrument (DESI), shown in this illustration, will be mounted on the 4-meter Mayall telescope at Kitt Peak National Observatory near Tucson, Ariz. It will collect data on light from 35 million galaxies and quasars to make the biggest 3-D map of the universe ever.