by Bill Schulz, Lawrence Berkeley National Laboratory. A five-year quest to map the universe and unravel the mysteries of dark energy began officially on May 17, 2021, at Kitt Peak National Observatory near Tucson, Arizona. The Dark Energy Spectroscopic Instrument (DESI) will capture and study the light from more than 30 million galaxies and other distant objects, allowing scientists to construct a 3-D map of the universe with unprecedented detail. DESI is an international science collaboration that includes physicists from the University of Utah and is managed by the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) with primary funding from DOE’s Office of Science.