An international research team has unveiled the largest and most detailed three-dimensional map of the universe ever created, marking a significant milestone in the quest to understand dark energy.
The map, constructed using data from the Dark Energy Spectroscopic Instrument (DESI), charts the positions of over 47 million galaxies and quasars, far exceeding the project’s original target of 34 million celestial objects.
Mounted on the Nicholas U. Mayall Telescope at Kitt Peak National Observatory in Arizona, DESI employs 5,000 robotic fiber-optic positioners to simultaneously capture light from thousands of celestial bodies. The instrument reconfigures its fiber array approximately every 20 minutes to maintain precise alignment with distant targets, enabling efficient spectroscopic analysis across vast swaths of the sky.
By splitting incoming light into its component wavelengths, DESI allows researchers to calculate each object’s distance from Earth. Combined with positional data, this information reconstructs the large-scale structure of the cosmos in three dimensions, revealing how matter is distributed across space and time.
The project, which began full operations in May 2021, continued through challenges including the global pandemic and regional wildfires. Over five years of observation, the team not only surpassed its galaxy and quasar goals but too collected data on more than 20 million nearby stars to support Milky Way structure studies.
Michael Levi, DESI’s director, said the instrument performed beyond expectations, calling the results “incredibly exciting.” The map’s high resolution and extensive coverage offer unprecedented detail for tracing the universe’s expansion history.
Scientists plan to use the dataset to investigate dark energy—the mysterious force driving the accelerated expansion of the universe, which constitutes about 70% of its total energy content. By comparing the distribution of galaxies across different epochs, researchers hope to determine whether dark energy’s influence has remained constant or evolved over billions of years.
Officials noted that the success of the initial survey has prompted discussions about extending the observation campaign to further enhance the map’s depth and utility for cosmological research.
