Much of the universe remains invisible to us, and scientists at the U.S. Department of Energy’s Fermi National Accelerator Laboratory are developing new quantum technologies to search for it.
While ordinary matter makes up stars, planets and people, it accounts for only a small fraction of the universe’s mass. The rest is dark matter, a mysterious substance that does not reflect, emit or absorb light. Now, Fermilab associate scientist Yao Lu is leading a project to advance quantum technology that will enable searches for subtle, indirect signals from dark matter interactions.
Yao has received a 2025 DOE Early Career Award to fund his research. Yao’s work focuses on developing a scalable superconducting cavity array, which will enable quantum-enhanced searches for a dark matter candidate known as the dark photon.
Lu’s research will take place in the Superconducting Quantum Materials and Systems Center, hosted at Fermilab. SQMS is one of five DOE National Quantum Information Science Research Centers — part of a national initiative to develop the world’s most powerful quantum computers and sensors.

Dark photons are hypothetical particles that behave like an extremely weak, invisible version of an electromagnetic field. If they exist, they might occasionally deposit a tiny microwave signal into a detector.
The challenge for physicists is that they do not know the signal’s frequency in advance. It’s like scanning an endless radio dial of white noise, hoping to stumble upon a lone, faint broadcast from an unknown station. In a standard search, scientists use a microwave cavity, essentially a carefully engineered metal resonator, as a sensitive antenna. If a dark photon exists at the right frequency, it could deposit a faint signal into the cavity. But because the frequency is unknown, searches must tune and listen, one setting at a time.
To break through this scanning bottleneck, Lu is combining ultra-coherent cavity hardware with entangling operations, quantum-state preparation, and low-loss interconnects — specialized links that allow the cavities to share signals efficiently — so multiple cavities can function as a coordinated sensor array.
By linking the cavities via remote quantum entanglement, the sensors can operate as a single cohesive unit. This quantum-enhanced array allows the system to scan through the “radio dial” of frequencies much faster and with far greater sensitivity than a single sensor ever could.
“The key is not just building better cavities.” Lu said. “It is learning how to make many ultra-coherent sensors work together so entanglement becomes a real advantage in the experiment.”
A four-cavity prototype, designed as a foundation for larger arrays, is the project’s first milestone. While the initial system is modest in size, the architecture is built to scale.
“If we can demonstrate the right architecture and control at that scale, we can extend the same framework to much larger arrays,” Lu said.
The project leverages techniques from superconducting quantum computing, which are now proving especially powerful for sensing. These methods make it possible to prepare, entangle, and nondestructively measure highly excited nonclassical cavity states, which are key resources for turning quantum coherence into a practical sensing advantage.
Lu’s research aims to demonstrate a measurable quantum advantage in dark matter detection while also guiding the design of broader classes of quantum sensors, including future searches for particles such as axions. Beyond sensing, the same hardware and interconnect architecture is also key to the development of SQMS’s modular quantum computing and distributed quantum communication. These advances could ultimately benefit our society by enabling faster, more efficient computing systems and communication networks that are much more secure.
Fermi National Accelerator Laboratory is America’s national laboratory for particle physics and accelerator research. Fermi Forward Discovery Group manages Fermilab for the U.S. Department of Energy Office of Science. Visit Fermilab’s website at www.fnal.gov and follow us on social media.
The Superconducting Quantum Materials and Systems Center is one of the five U.S. Department of Energy National Quantum Information Science Research Centers. Led by Fermi National Accelerator Laboratory, SQMS is a collaboration of more than 40 partner institutions — national labs, academia and industry — working together to bring transformational advances in the field of quantum information science. The center leverages Fermilab’s expertise in building complex particle accelerators to engineer multiqubit quantum processor platforms based on state-of-the-art qubits and superconducting technologies. For more information, please visit sqmscenter.fnal.gov.
Inside an unassuming building on the campus of the South Dakota School of Mines and Technology in Rapid City, a small research team is tackling a challenge vital to the world’s largest neutrino experiment. Their work focuses on powering photon detectors, key instruments that could contribute to revealing our universe’s deepest secrets and ultimately uncover new physics.
Associate Professor David Martinez Caicedo is leading a research group of undergraduate and graduate students at the university, along with postdoctoral researchers, to perfect a method for carefully sending power to the highly sensitive photon detectors that will be installed within the Deep Underground Neutrino Experiment’s massive far detector modules.

Martinez is a member of the international collaboration for DUNE, composed of more than 1,500 scientists and engineers from over 35 countries and hosted by the U.S. Department of Energy’s Fermi National Accelerator Laboratory. DUNE will seek to deepen our understanding of neutrinos — mysterious subatomic particles that may have played a central role in tipping the scale toward there being more matter than antimatter in our universe.
Inception of an idea
In 2019, two Fermilab researchers began discussing ways to provide power to the two liquid-argon detector modules that would be installed at the DUNE far site a mile underground at the Sanford Underground Research Facility in South Dakota. While sending power to the first detector module was relatively straightforward, the second, called the vertical drift, presented a unique challenge due to its design. Flavio Cavanna, a senior scientist with Fermilab, was the point person to solve this problem.
“In the vertical drift design, there is no easy way to provide power to the photon detectors,” Cavanna said. “My first idea was to put it on the cathode, but we didn’t have any idea for how this would work.”
Cavanna reached out to Bill Pellico, a senior engineer with Fermilab, to chart a course to provide power to the vertical drift that would be compatible with the existing design of the detector module.
“Bill is an expert on high voltage and power delivery, and he came up with a couple ideas, one of which was to use power over fiber,” Cavanna said. While this technology exists in the market already, there was no clear indication it would work within a liquid-argon environment.
“In the vertical drift design, there is no easy way to provide power to the photon detectors.”
Flavio Cavanna, Fermilab
“I had some experience with using fiber technology, so in combination with Bill’s previous experience and proposal, we selected to move forward with exploring this technology,” Cavanna said.
After several years of testing and demonstrations, the DUNE collaboration approved the technology, and work began at CERN and Fermilab on prototypes. At that point, other institutions, including SD Mines and Stony Brook University in New York, became involved in the construction, quality control and installation of the power-over-fiber technology.
Going to extremes
To study neutrino interactions, DUNE will use liquid-argon time projection chamber technology. At room temperature argon is a gas, so for argon to reach its liquid state, it must be chilled below minus 300 degrees Fahrenheit (minus 184 degrees Celsius). Such extreme temperatures make it essential for researchers to find new ways to power the photon detectors.
“Particles generated after a neutrino interacts with an argon atom in the detector produce ionization electrons and scintillation light,” Martinez explained at SD Mines. “To detect the scintillation light, the photon detectors need to be powered while immersed in liquid argon. With these challenges in mind, we pursued a novel application of power-over-fiber technology.”
According to Pellico, the technology has strengths that prove especially useful where electronics in contact with high voltages need to be isolated from their surroundings.
“Optical fibers have previously been used at very low temperatures, such as in space applications or quantum computing experiments, so this is not new,” Pellico noted. “However, their use for carrying high-intensity photon power in a cryogenic application is novel.”

This innovative use of power-over-fiber technology allows the photon detectors to operate reliably in liquid argon and the high-voltage conditions of DUNE’s detectors. In addition to the temperature, the sheer size of DUNE’s detectors also pose a challenge. At nearly six stories tall and more than 72 yards long, scintillation light produced far from the photon detectors may not be collected. To improve light collection efficiency, researchers plan to increase photon detector coverage in parts of the detector that were not previously considered because of high-voltage environment. Increasing light collection will improve the ability to study neutrinos from supernovae and solar neutrinos and could help scientists search for new physics beyond the Standard Model.
“So, how do you enhance the monitoring of interactions occurring inside the detector? We needed a system that allows us to place more photon detectors,” Pellico said. “The power-over-fiber technology would allow researchers to better analyze those interactions that would perhaps otherwise go undetected by having the ability to place more detectors.”
After a three-year effort of experimentation and working with different vendors, the power-over-fiber team was able to develop a system that could work at extremely cold temperatures and provide the DUNE researchers the line-of-sight they needed.
“We ended up working with a vendor that was able to obtain up to 55% optical to electrical power conversion efficiency under cryogenic conditions, so we can use this efficient system to power photon detectors,” Pellico said. “We now have a way to place photon detectors anywhere in the detector.”
Launch-ready technology
Importantly, this power-over-fiber technology is being treated as “launch technology.”
“Just like launching a system into space, once the technology is deployed inside the detectors, it is expected to be operational for the entirety of those detectors’ lifetimes,” Pellico said. “Repairs are not feasible.”
Unlike conventional copper cables, power-over-fiber components such as lasers, fibers and optical power converters are very delicate. This could mean that, if not carefully handled during installation, issues could arise during assembly of the DUNE far detector. To ensure success, Martinez and his team at SD Mines have engaged in significant testing and planning in advance of installation. Due to the customization of the technology, all the components must be inspected and qualified — not only at room temperature but also at cryogenic temperatures.
“To characterize how the power-over-fiber system works in cryogenic conditions, we built a long-term test here at SD Mines,” said Jairo Rodriguez, a graduate student in Martinez’s group.
“We send laser light through a fiber to an optical power converter that is inside a dewar [an insulated storage container] filled with liquid nitrogen, and we monitor its voltage to check proper system behavior,” added Denis Torres, a graduate student also working in the group.
It was very exciting to see this milestone, not just for DUNE, but for the high-energy physics community as well.”
David Martinez Caicedo, SD Mines
This testing has been running for over two years and the system has remained operational, with data demonstrating the stability of the system. “We are monitoring the system every day and determine if there are any variations and where these could come from,” Denis said.
Diana Leon, a graduate student in the SD Mines group, traveled to CERN in 2023 and 2024 to help lead in the installation of the power-over-fiber system for ProtoDUNE, a prototype of the DUNE detector. Commissioning and operation of the power-over-fiber technology followed in 2025. This test was critical for determining how effectively it can be applied in a large-scale detector prototype. After commissioning, and prior to the start of operation, the team anxiously watched as the detector was powered up.
As they had hoped, all of the photon detectors activated and functioned according to plan. “When all of the photon detectors were turned on, we were so happy to see the power-over-fiber technology working after many years of work,” Leon recalled.
“When we clicked that button in 2025, all the channels were working just like the light bulb in your room,” Cavanna recalled. “In one click, they didn’t blink or have any faults. It’s been a year and there’s been no failure.”
“It is one of the greatest memories I’ve had in my entire life,” Cavanna added.
“I was here in South Dakota when the photon detectors on the prototype detector at CERN turned on,” added Martinez. “I received a text message early in the morning that read, ‘It works!’ It was very exciting to see this milestone, not just for DUNE, but for the high-energy physics community as well.”

Diana will soon be traveling to CERN again, this time to practice the mechanical integration of power-over-fiber technology. The work will occur at CERN on a mock-up detector, which will be the same height as the actual DUNE detector.
Martinez emphasized the importance of the close collaboration of his group with Fermilab and is also proud of the work the power-over-fiber team at SD Mines has accomplished for DUNE. “The students are involved in the entire process,” he said. “They had the opportunity to put their hands on it, installing and operating power-over-fiber technology and closely collaborating with experts at Fermilab. All the team here, including undergraduate and graduate students, the postdoctoral researcher, and Connie Krosschell, our department secretary, have a role to play. So, everyone has their own contribution, but we pull together as a team.”
Benefits beyond DUNE
Biswaranjan Behera, a former postdoctoral researcher who worked with both Pellico and Martinez and is currently a Ramanujan Fellow at the Center for High Energy Physics at the Indian Institute of Science in Bangalore, noted that power-over-fiber technology at cryogenic temperatures could be used far beyond high-energy particle physics experiments.
“With innovative technologies working together, including the novel implementation of power-over-fiber, DUNE has strong potential for groundbreaking discoveries,” Behera said. “But, also, we are working on a new application of the technology for use in other cryogenic environments.”
“The DUNE future is bright, and we are making engineering advances and developing tools necessary for cutting-edge neutrino research.”
Biswaranjan Behera, Indian Institute of Science
Certain sectors of the economy, such as quantum computing, data centers and space exploration stand to benefit from this technology. Power over fiber technology offers low noise, superior isolation, optimal efficiency and is immune to electromagnetic interference, while also performing reliably at cryogenic temperatures.
“This can be used in any type of system where it’s cold and you want to monitor what’s going on,” Pellico said. “Electronics become more efficient at cryogenic temperatures, creating opportunities for AI data centers to operate in extreme cold with improved energy efficiency.”
Ultimately, the advancements made for the Deep Underground Neutrino Experiment are paving the way for a more integrated, high-tech future. “The DUNE future is bright, and we are making engineering advances and developing tools necessary for cutting-edge neutrino research,” Behera added. “In addition, with artificial intelligence already widely employed in DUNE, great things are on the horizon.”
Fermi National Accelerator Laboratory is America’s national laboratory for particle physics and accelerator research. Fermi Forward Discovery Group manages Fermilab for the U.S. Department of Energy Office of Science. Visit Fermilab’s website at www.fnal.gov and follow us on social media.
Spring has blossomed on the prairie land at Fermi National Accelerator Laboratory with one of the laboratory’s most cherished traditions: the arrival of the first newborn American bison calf. Today, the first cinnamon-colored baby bison was born and is healthy, and the calf is staying close to its mother as it takes its first steps on the open grassland.

Establishing and maintaining the bison herd at Fermilab is a bold symbol of the laboratory’s achievements on the frontiers of science. By establishing the herd of bison, the founder of Fermilab, Robert Wilson, intended to connect the laboratory with the Illinois prairie that once dominated the region. He believed that a cutting‑edge scientific facility should also honor the history and environment of the land it occupies.
“People come to Fermilab for world‑class science, but the bison herd has become one of the most beloved parts of our identity,” said Fermilab Director Norbert Holtkamp. “Fermilab occupies a very special place with the local community and in the global scientific landscape.”
Bison are hardy animals that can live outside year-round in most any weather. The Fermilab herd is managed to live naturally on the prairie, with Fermilab keepers only providing them with structures within corrals to block the strong winds that swirl across Fermilab’s flat landscape.

The current herd consists of two bulls and 23 female cows. Bison calving season at the lab usually starts in the middle of April and continues until June. Each spring, the lab’s herdsman Cleo Garcia, expects approximately 20 new calves. Last year, 20 babies were born, with four calves arriving by surprise in late summer.
During calving season, Garcia feeds the bison and checks on them daily, studying the cows for hints that they may soon give birth. He also monitors the young calves to make sure that they are healthy and adapting well to their new environment. In the winter, the herd’s food is supplemented with hay and grain when grass is not as plentiful.

Fermilab refreshes the bulls in the herd every five to seven years. The bulls are pure-bred American bison and have been genetically tested. This is important in maintaining the health of the herd. Eleven years ago, Fermilab tested the entire herd and determined that there were no domesticated cattle genes present.
To the staff members, the arrival of the calves is more than just a charming sight — it is a reminder of the lab’s commitment to blending world‑class scientific research with an appreciation of nature. The calves grow up alongside the lab’s ongoing ecology and restoration efforts, including conservation of wildlife throughout the 6,800 acres of land by maintaining a healthy, biodiverse ecosystem.
The bison stand as a bridge between past and future, linking a modern particle physics laboratory with the natural landscapes that once dominated northern Illinois. And as the new calves take their first steps, they continue a legacy that has become a part of Fermilab’s identity since 1969.
The public is welcome to view the herd anytime on the web 24-7 with the bison camera or by visiting Fermilab’s outdoor public areas from dawn to dusk every day of the week. Please visit the hours and public access webpage for information and requirements for visiting the lab, and celebrate the arrival of spring along with Fermilab’s newest additions.
The Fermilab site has been designated a National Environmental Research Park by the U.S. Department of Energy. The lab’s environmental stewardship efforts are supported by the Department of Energy Office of Science and by Fermilab Natural Areas.
Fermi National Accelerator Laboratory is America’s premier national laboratory for particle physics and accelerator research. Fermi Forward Discovery Group manages Fermilab for the U.S. Department of Energy Office of Science. Visit Fermilab’s website at www.fnal.gov and follow us on social media.
A tiny elementary particle called the muon has won a big prize, the Breakthrough Prize in Fundamental Physics. Fermilab researchers are among the winners of this year’s Breakthrough Prize, one of the world’s most notable and prestigious scientific awards that celebrates new scientific discoveries. Each prize is $3 million and is presented in the fields of Life Sciences, Fundamental Physics and Mathematics.
The 2026 award in Fundamental Physics recognized three generations of the Muon g-2 experiment, which provided the world’s most precise measurement to date of the muon, one of the fundamental subatomic particles. The experiment began at CERN in the 1970s, shifted to Brookhaven National Laboratory in the 1990s and concluded at Fermilab with final publication in 2025.
“I’m proud of the role Fermilab played in the Muon g-2 experiment, which is set to stand as the most accurate measurement of the muon for years to come,” said Fermilab Director Norbert Holtkamp. “Fermilab has a strong role as a collaborator and integrator, and this was demonstrated by our work with our colleagues at CERN, Brookhaven and institutions from around the world.”
The Breakthrough Prize, renowned as the “Oscars® of Science,” recognizes the world’s top scientists. The $3 million prize is being awarded to the hundreds of collaborators who contributed to publications reporting key results from CERN, Brookhaven and Fermilab.
Fermilab scientist Chris Polly was among the four members of the scientific collaborations who accepted the prize. Others included: Bradley Lee Roberts of Boston University, William M. Morse of Brookhaven National Laboratory and David Hertzog of the University of Washington. The prize was presented at a ceremony at the Barker Hangar in Santa Monica, California, on Saturday, April 18, 2026.

The three generations of Muon g-2 experiments were designed to measure the magnetic moment of the muon with ever-increasing precision, exploring the quantum realm where particles briefly appear and vanish—and where even tiny deviations could point to entirely new laws of nature outside of the current Standard Model of Particle Physics.
The latest and most precise measurement of the muon’s magnetic moment was announced by Fermilab in 2025 and was important because it provided a sensitive test of the Standard Model of particle physics.
Fermilab led the most recent stage of the experiment that reused a 50-foot-diameter superconducting magnetic storage ring from the Brookhaven National Laboratory experiment when it was transported on a land-and-sea journey in 2013 from Long Island, New York to Fermilab in Illinois.

In 2021, the first result from the Muon g-2 experiment at Fermilab confirmed a two-decade-old measurement from Brookhaven, revealing a tantalizing tension with established theoretical predictions—while new calculations continue to refine what the Standard Model itself expects. The second run at Fermilab further improved the precision measurement. The third and final result in 2025 was in perfect agreement with the experiment’s previous results and proved to be the world’s most precise measurement of the muon magnetic anomaly.
The Breakthrough Prizes were founded by Sergey Brin, Priscilla Chan and Mark Zuckerberg, Julia and Yuri Milner, and Anne Wojcicki and have been sponsored by foundations established by them. Selection Committees composed of previous Breakthrough Prize laureates in each field choose the winners. Information on the Breakthrough Prize is available at breakthroughprize.org.
Fermi National Accelerator Laboratory is America’s premier national laboratory for particle physics and accelerator research. Fermi Forward Discovery Group manages Fermilab for the U.S. Department of Energy Office of Science. Visit Fermilab’s website at www.fnal.gov and follow us on social media.
Editor’s note: The following press release was published by Lawrence Berkeley National Laboratory.
Fermilab contributed key elements to the Dark Energy Spectroscopic Instrument, which include the online databases used for data acquisition and the software that ensures that each of the 5,000 robotic positioners is precisely pointing to their celestial targets to within a tenth of the width of a human hair.
Other Fermilab contributions include the corrector barrel, hexapod and the testing and packaging of DESI’s charge-coupled devices, or CCDs. The CCDs convert the light passing through the lenses from distant galaxies into digital information that can then be analyzed by the collaboration. Fermilab scientists continue to participate in data-taking and analysis.
Key takeaways
- The Dark Energy Spectroscopic Instrument, one of the most extensive surveys of the cosmos ever conducted, finished all observations for its originally planned 3D map of the universe.
- Scientists use DESI’s map to study dark energy, one of the biggest mysteries in physics.
- Researchers expected to gather data on 34 million galaxies and quasars during the five-year survey, but the instrument performed so efficiently that it captured more than 47 million galaxies and quasars, plus more than 20 million nearby stars used to study the Milky Way.
- DESI is continuing observations and will extend its map to cover more of the sky to better study dark energy as well as dark matter.
Last night, the 5,000 fiber-optic eyes of the Dark Energy Spectroscopic Instrument (DESI) swiveled onto a patch of sky near the Little Dipper. Roughly every 20 minutes, they locked on to distant pinpricks of light, gathering photons that had traveled toward Earth for billions of years. When the sun rose, collaborators marked completion of a major milestone: successfully surveying all of the area in DESI’s originally planned map of the universe.
The five-year survey, finished ahead of schedule and with vastly more data than expected, has produced the largest high-resolution 3D map of the universe ever made. Researchers use that map to explore dark energy, the fundamental ingredient that makes up about 70% of our universe and is driving its accelerating expansion.

By comparing how galaxies clustered in the past with their distribution today, researchers have traced dark energy’s influence over 11 billion years of cosmic history. Surprising results using DESI’s first three years of data hinted that dark energy, once thought to be a “cosmological constant,” might be evolving over time. With the full set of five years of data, researchers will have significantly more information to test whether that hint disappears or grows. If confirmed, it would mark a major shift in how we think about our universe and its potential fate, which hinges on the balance between matter and dark energy.
DESI’s quest to understand dark energy is a global endeavor. The international experiment brings together the expertise of more than 900 researchers (including 300 PhD students) from over 70 institutions. The project is managed by the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), and the instrument was constructed and is operated with funding from the DOE Office of Science. DESI is mounted on the U.S. National Science Foundation’s Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory (a program of NSF NOIRLab) in Arizona.
“DESI’s five-year survey has been spectacularly successful,” said Michael Levi, DESI director and a scientist at Berkeley Lab. “The instrument performed better than anticipated. The results have been incredibly exciting. And the size and scope of the map and how quickly we’ve been able to execute is phenomenal. We’re going to celebrate completion of the original survey and then get started on the work of churning through the data, because we’re all curious about what new surprises are waiting for us.”
DESI has now measured cosmological data for six times as many galaxies and quasars as all previous measurements combined. The collaboration will immediately begin processing the completed dataset, with the first dark energy results from DESI’s full five-year survey expected in 2027. In the meantime, DESI scientists continue to analyze the survey’s first three years of data, refining dark energy measurements and producing additional results on the structure and evolution of the universe, with several papers planned later this year.
“The Dark Energy Spectroscopic Instrument has truly exceeded all expectations, delivering an unprecedented 3D map of the universe that will revolutionize our understanding of dark energy,” said Kathy Turner, Program Manager for the Cosmic Frontier in the Office of High Energy Physics at the Department of Energy. “From its inception, we envisioned a project that would push the boundaries of cosmology, and to see it come to such a spectacularly successful completion for its initial survey, ahead of schedule and with such rich data, is incredibly rewarding. The dedication and ingenuity of the entire DESI collaboration have made this world-leading science a reality, and I am immensely proud of the groundbreaking results we are already seeing and the discoveries yet to come as we continue to explore the mysteries of our cosmos.”
An observing machine
DESI began collecting data in May 2021. Since then, the instrument has far surpassed the collaboration’s original goals. The plan was to capture light from 34 million galaxies and quasars (extremely distant yet bright objects with black holes at their cores) over the five-year sky survey. DESI instead observed more than 47 million galaxies and quasars and 20 million stars.
The project’s success is even more impressive in light of several challenges. DESI is a complicated machine with thousands of parts to maintain. In 2020, final tests of the instrument were interrupted by the COVID-19 pandemic. In 2022, the Contreras Fire swept over Kitt Peak but, through the efforts of firefighters and staff, did not damage the telescope. Recovery efforts were slowed by monsoons and mudslides.
“DESI is a complicated but wonderfully robust system, and it’s been a huge amount of fun to see it come together and work so well for such a long time,” said Connie Rockosi, co-instrument scientist for DESI and a professor at UC Santa Cruz and UC Observatories. “We’ve learned about the instrument over five years, and we know its personality and behavior pretty well. That’s important because having the instrument be so efficient is why we’re here at the end of DESI’s original survey with such great data and so much science coming out.”
To map objects, researchers use specially-designed software to optimize DESI observations and decide where to point the telescope. Robotic positioners precisely line up optical fibers that are accurate to within 10 microns, or less than the width of a hair. Ten spectrographs then measure and split the light into its separate colors to determine each object’s position, velocity, and chemical composition. Each night, roughly 80 gigabytes of data streams through ESnet, DOE’s high-speed science network, to supercomputers at Berkeley Lab’s National Energy Research Scientific Computing Center (NERSC). Initial processing lets researchers do quality assurance and make any adjustments needed for the next night of observations.
Collaborators across the project found ways to make DESI more efficient. Efforts spanned telescope operations, tweaks to the instrument hardware, updates to software, observing protocols, methods to reduce the data, and more.
“There’s been constant monitoring and intervention to make the whole thing tick,” said Adam Myers, co-manager for DESI’s survey operations and professor at the University of Wyoming. “And the DESI team is remarkable. This huge group of people have all been working on whether they could save one or two or three percent in their particular area, and when you add it all up, it results in these amazing gains in efficiency.”
DESI is designed to make several overlapping passes of the sky to observe its full footprint (and sometimes make repeated observations of faint objects). The survey was so efficient, the team completed an entire additional pass over the sky for the “Bright-Time Survey,” which is carried out when reflected light from the moon hinders observations of faint and distant objects. All told, DESI made five passes during the Bright-Time Survey and seven during the Dark-Time Survey, covering about two-thirds of the northern night sky.
The sky’s the limit
DESI will continue observations through 2028 and grow its map by about 20%, from 14,000 square degrees to 17,000 square degrees. (For comparison, the moon covers approximately 0.2 square degrees, and the full sky has over 41,000 square degrees). The extended map will cover parts of the sky that are more challenging to observe: areas that are closer to the plane of the Milky Way, where bright nearby stars can make it harder to see more distant objects, or further to the south, where the telescope must account for peering through more of Earth’s atmosphere.
The experiment will also revisit the existing area of the map to collect data from a new set of galaxies: more distant and faint “luminous red galaxies.” These will provide an even denser and more detailed map in the regions DESI has already covered, giving researchers a clearer picture of the universe’s history.
Researchers will also study nearby dwarf galaxies and stellar streams, bands of stars torn from smaller galaxies by the Milky Way’s gravity. The hope is to better understand dark matter, the invisible form of matter that accounts for most of the mass in the universe but has never been directly detected.
The extended map is already underway. When it became clear that DESI would operate beyond its original survey plan, researchers began interleaving the new observations with the ongoing DESI survey to optimize the use of telescope time and keep the instrument from sitting idle.
“We’ve built a remarkable piece of equipment that met all our expectations and then some,” Levi said. “Now we’re pushing beyond our original plan. We don’t know what we’ll find, but we think it’ll be pretty exciting.”

DESI is supported by the DOE Office of Science and by the National Energy Research Scientific Computing Center, a DOE Office of Science national user facility. Additional support for DESI is provided by the U.S. National Science Foundation; the Science and Technology Facilities Council of the United Kingdom; the Gordon and Betty Moore Foundation; the Heising-Simons Foundation; the French Alternative Energies and Atomic Energy Commission (CEA); the Secretariat of Science, Humanities, Technology and Innovation (SECIHTI) of Mexico; the Ministry of Science and Innovation of Spain; and the DESI member institutions.
The DESI collaboration is honored to be permitted to conduct scientific research on I’oligam Du’ag (Kitt Peak), a mountain with particular significance to the Tohono O’odham Nation.
Lawrence Berkeley National Laboratory (Berkeley Lab) is committed to groundbreaking research focused on discovery science and solutions for abundant and reliable energy supplies. The lab’s expertise spans materials, chemistry, physics, biology, earth and environmental science, mathematics, and computing. Researchers from around the world rely on the lab’s world-class scientific facilities for their own pioneering research. Founded in 1931 on the belief that the biggest problems are best addressed by teams, Berkeley Lab and its scientists have been recognized with 17 Nobel Prizes. Berkeley Lab is a multiprogram national laboratory managed by the University of California for the U.S. Department of Energy’s Office of Science.
DOE’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science.