DESI, the Dark Energy Spectroscopic Instrument, will expand our knowledge about the accelerating expansion of the universe. This expansion is driven by mysterious dark energy, which we know very little about.
DESI will create a 3D map of tens of millions of galaxies, and millions of brilliant objects called quasars, during five years of observations. The map, based on measurements of light, called spectra, for the galaxies and quasars, will help scientists gauge their distances and learn how quickly they are moving away from us.
Lawrence Berkeley National Lab/KPNO/NOIRLab/NSF/AURA