Over one billion galaxies blaze bright in colossal map

The universe is teeming with galaxies, each brimming with billions of stars. Though all galaxies shine brightly, many are cloaked in dust, while others are so distant that to observers on Earth, they appear as little more than faint smudges.
By creating comprehensive maps of even the dimmest and most-distant galaxies, astronomers are better able to study the structure of the universe and unravel the mysterious properties of dark matter and dark energy.
The largest such map to date has just grown even larger, with the tenth data release from the DOE's Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Survey.
The DESI Legacy Imaging Survey expands on the data included in two earlier companion surveys: the Dark Energy Camera (DECam) Legacy Survey and the Beijing-Arizona Sky Survey.
Jointly, these three surveys imaged 14,000 square degrees of the sky visible from the northern hemisphere, using telescopes at NSF's NOIRLab's Kitt Peak National Observatory (KPNO) and Cerro Tololo Inter-American Observatory (CTIO) in Chile.
This ambitious six-year effort involved three telescopes, one petabyte of data, and 100 million CPU hours on one of the world's most powerful computers at the US Department of Energy's National Energy Research Scientific Computing Center.
This effort culminated in the largest two-dimensional map of the sky ever created.
One of the main purposes of this map is to identify roughly 40 million target galaxies for the DESI Spectroscopic Survey, which is aimed at understanding dark energy by precisely mapping the expansion history of the universe over the last 12 billion years.

Ref: Forbes; NOIRLab