The Dark Energy Survey Collaboration collected information on hundreds of millions of galaxies across the universe using the U.S. Department of Energy-fabricated Dark Energy Camera, mounted on the U.S. National Science Foundation Víctor M. Blanco 4-meter Telescope at CTIO, a program of NSF NOIRLab. Their completed analysis combines all six years of data for the first time and yields constraints on the universe’s expansion history that are twice as tight as past analyses.

The Dark Energy Survey (DES) is an international, collaborative effort to map hundreds of millions of galaxies, detect thousands of supernovae, and find patterns of cosmic structure that will help reveal the nature of the mysterious dark energy that is accelerating the expansion of our universe.

From 2013 to 2019, the DES Collaboration carried out a deep, wide-area survey of the sky using the 570-megapixel DOE-fabricated Dark Energy Camera (DECam), mounted on the NSF Víctor M. Blanco 4-meter Telescope at NSF Cerro Tololo Inter-American Observatory (CTIO) in Chile. For 758 nights over six years, the DES Collaboration recorded information from 669 million galaxies that are billions of light-years from Earth, covering an eighth of the sky.