Long-exposure star trails over the Mayall Telescope, where DESI is installed. (Credit: Luke Tyas/Berkeley Lab and KPNO/NOIRLab/NSF/AURA)
Berkeley Lab’s Dark Energy Spectroscopic Instrument (DESI) has released a dataset mapping a whopping 18.7 million celestial objects. The dataset is the largest 3D cosmic survey ever made available to the scientific community. This astronomical treasure trove, containing information on roughly million stars, 13.1 million galaxies, and 1.6 million quasars.
The newly released 270-terabyte dataset spans observations from the first 13 months of DESI’s main survey, collected between May 2021 and June 2022. The survey covers more than 14,000 square degrees of sky. That’s nearly one-third of the entire night sky. It also includes precise redshift measurements that allow researchers to map objects up to 11 billion light-years away. With more than twice as many extragalactic sources as all previous 3D spectroscopic surveys combined, DESI’s data is already supporting research across cosmology, dark matter, and galaxy evolution.
The Dark Energy Spectroscopic Instrument (DESI), shown here as a cylindrical apparatus mounted within the Mayall Telescope’s framework, uses 5,000 robotic fiber-optic “eyes” to simultaneously capture spectra from distant celestial objects. (Credit: Marilyn Sargent/Berkeley Lab)
The DESI instrument taps 5,000 automated, high-precision robotic fiber optic positioners to simultaneously capture spectra. The resulting data flows through the dedicated high-speed ESnet network to the National Energy Research Scientific Computing Center (NERSC), where Berkeley Lab’s Perlmutter supercomputer processes the information at speed—nearly 40 times faster than previous systems.
This dataset is the result of significant international collaboration, uniting over 900 researchers from more than 70 institutions worldwide. The significance of Data Release 1 (DR1) is underscored by its sheer scale; it contains information on more than twice as many unique objects outside our galaxy as documented by all previous 3D spectroscopic surveys combined.
The entire DR1 dataset is freely available to the global research community through the National Energy Research Scientific Computing Center (NERSC) and can be explored visually via the interactive Legacy Survey Sky Browser portal.
