Scientists have released the largest two-dimensional color map of the universe ever made, charting nearly 4 billion stars, galaxies, and other celestial objects. This colossal map, comprising 5.6 trillion pixels, is now publicly accessible for anyone to explore online. The DESI Legacy Imaging Surveys team spent 13 years compiling the data for this comprehensive cosmic view, which covers approximately 75% of the night sky.[newscenter+5]
Mapping the Cosmos
The new map provides a deep and detailed view of the extragalactic universe, largely unhindered by the dust and stars within our own Milky Way galaxy. It was built from a staggering 263,407 individual telescope exposures, collected over 2,285 nights. These images came from three major ground-based sky surveys: the Dark Energy Camera Legacy Survey (DECaLS) at NSF Cerro Tololo Inter-American Observatory, the Mayall z-band Legacy Survey (MzLS) at NSF Kitt Peak National Observatory, and the Beijing-Arizona Sky Survey (BASS) at the University of Arizona's Steward Observatory. Data from NASA's Wide-field Infrared Survey Explorer (WISE) satellite mission also supplemented the effort.[sci+8]
More than 160 scientists contributed to the extensive data collection for the project, with a dedicated team of 20 astronomers producing the final dataset. David Schlegel, a co-lead of the Legacy Surveys and a scientist at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), noted that the Legacy Imaging Viewer is now a fundamental tool for astronomy research. He stated that astronomers often begin their work by checking the viewer to understand what they are observing.[sci+8]
A Foundation for Future Discoveries
This expansive 2D map serves a critical role as the foundation for the Dark Energy Spectroscopic Instrument (DESI) survey. DESI aims to create the largest high-resolution three-dimensional map of the universe to measure galaxy distances and investigate the mysteries of dark energy. Dark energy is the enigmatic force believed to be driving the accelerating expansion of our universe.[newscenter+12]
The map includes a vast array of celestial objects, from distant galaxies like Messier 96, located about 35 million light-years from Earth, to stars and asteroids within our solar system's neighborhood. Researchers can use this data to search for rare phenomena such as gravitational lenses, observe fleeting events like supernovae, and investigate dark matter, the invisible substance accounting for most of the universe's mass.[newscenter+6]
Public Access and Scientific Impact
The entire treasure trove of data is available for public use through the Legacy Survey Sky Viewer, making it accessible to astronomers and citizen scientists alike. This public access allows anyone to explore the sky and combine the map with their own observations to gain a better understanding of the universe. Arjun Dey, another co-lead of the Legacy Surveys and an astronomer at NSF NOIRLab, emphasized that "the skies belong to everyone" and this survey offers everyone a chance to marvel at its wonders.[newscenter+12]
The map builds on earlier versions from the DESI Legacy Imaging Surveys, which have already proven invaluable to the scientific community. To date, more than 1,800 science papers have referenced data from these surveys, highlighting their significant contribution to astronomical research. Scientists expect this new, most comprehensive 2D map to remain a vital resource for years to come. It will continue to aid investigations into the expansion history of the universe and the formation of galaxies.[newscenter+13]
