Inside DESI, an Ambitious Project to Map the Universe in 3D

DESI, the Dark Energy Spectroscopic Instrument, aims to map the universe in three dimensions and shine a light on the mysterious force of nature we call dark energy. Its five-year sky survey will begin in 2020, but the project achieved an important milestone this fall when collaborators started assembling key pieces of equipment at Kitt Peak National Observatory in Arizona. A picture may be worth a thousand words, but exploring DESI by pictures and numbers offers an in-depth glimpse into this un...