Scientists have made significant progress in their efforts to understand dark energy by completing observations of the entire region of interest in the Dark Energy Spectroscopy Instrument (DESI) 3D map of the universe.
The project finished ahead of schedule and provided much more data than originally anticipated. This map is the most detailed, high-resolution 3D representation of the universe ever created. Researchers plan to use it to investigate dark energy, a mysterious force believed to make up about 70% of the universe.
47 million galaxies mapped in greater detail than ever before
Over five years of observations, DESI recorded more than 47 million galaxies and quasars, along with 20 million stars. Paul Martini, an instrument scientist during DESI’s construction and commissioning and a professor of astronomy at Ohio State University, said these measurements are already providing new insights into how the universe is structured and how it has changed over time.
“DESI is a great international collaboration, and its incredibly fruitful scientific results are a prime example of its impact on the broader scientific community,” he said.
A global effort to understand dark energy
DESI represents a large-scale international collaboration involving more than 900 researchers (including 300 doctoral students) from more than 70 institutions. The project is led by the Department of Energy’s Lawrence Berkeley National Laboratory. Scientists at The Ohio State University played a key role in important discoveries, from analyzing early results to uncovering unexpected changes in the behavior of dark energy.
“The Ohio State University has made the largest contribution to the measurement, operations, and analysis infrastructure of any DESI university group,” said Klaus Honscheid, lead scientist for DESI instrument operations and professor of physics at The Ohio State University. “We are proud of the world-leading results of our joint research on dark energy and delighted that it has received significant international media attention.”
Overcoming challenges under investigation
Completing the study within five years is not without obstacles. One of the biggest setbacks came in 2022. The Contra wildfire disrupted the observatory’s power and internet service for months. Still, the team managed to recover quickly and continue working, said Ashley Ross, lead scientist for DESI’s large structure catalog and assistant professor of physics at The Ohio State University.
“By coming up with creative solutions to address unexpected problems, we carefully and confidently used the high-quality data we collected each night to obtain the exciting cosmological constraints for which DESI is now known,” Ross said.
What new data reveals about the universe
With the complete data set in hand, researchers now have a stronger foundation to test long-standing ideas about the balance of dark energy and matter. The results could lead to major changes in the way scientists understand the universe and predict its future.
DESI has already collected measurements from more than six times the number of galaxies and quasars than all previous surveys combined. The team will begin processing this full dataset soon, with the first results of the full five-year study expected in 2027.
Next steps and future observations for DESI
Although its initial mission has been completed, DESI will continue observing the skies until 2028. Future work will focus on areas that are difficult to observe and help build a more detailed map of the universe. This expanded field of view could also improve the study of nearby structures such as dwarf galaxies and stellar streams, providing a clearer picture of how the universe formed and evolved, Honscheid said.
Meanwhile, researchers at Ohio State University continue to refine dark energy measurements using the first three years of observational data. They are also working to improve how the telescope uses its time and improve the instrument’s performance for future discoveries.
“The expanded survey coverage will greatly improve the constraints on cosmological parameters and improve dark matter programs,” Honscheid said. “But these results were only possible because our operations team worked incredibly hard to advance the investigation.”
Contributors and support
Other Ohio State contributors to DESI include Matthew Berno, Mikel Charles, Carl Coker, Rebecca Coles, Andrei Kuseu, Xin-Yi Chen, Mark Derwent, Ann Elliott, Jacques Elvin Poole, Lauren Enesar, Kevin Fanning, Simon Philbert, Megan Herbold, Jennifer Johnson, Naim Karakairi, Hui Kong, Claire Laman, and Thomas. O’Brien, Daniel Pappalardo, Richard Pogge, Anna Poledon, Michael Rushkovetsky, John Schober, Peter Taylor, Win Turner, David Weinberg, Molly Wolfson, Eric Zaborowski.
DESI is supported by the DOE Office of Science and the National Energy Research Scientific Computing Center, a DOE Office of Science National User Facility. Additional support for DESI is provided by the National Science Foundation. UK Science and Technology Facilities Council. Gordon and Betty Moore Foundation. Heising-Simons Foundation. French Alternative Energy and Atomic Energy Commission (CEA). Mexican Secretariat of Sciences, Humanities, Technology and Innovation (SECIHTI). Spanish Ministry of Science and Innovation. By DESI member institutions.
The DESI Collaborative is honored to have been granted permission to conduct scientific research on Iorigam Duag (Kitt Peak), a mountain of special significance to the Tohono Oodham Nation.
