![\"Full](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/10\/scifair-desi-dark-energy-map-1280x1280.jpg\")
The largest-ever 3D map of the universe, created by the now-completed five-year DESI survey. Earth is at the center of this map, and every point represents a galaxy. Credit: DESI Collaboration and DESI Member Institutions\/DOE\/KPNO\/NOIRLab\/NSF\/AURA\/R. Proctor\/M. Zamani (Image Processing, NSF NOIRLab) <\/p>\n
\u201cAs we look back at galaxies further and further away from us, we\u2019re looking back in time\u2014the time it takes for the light to reach us from these distant galaxies,\u201d explained Will Percival<\/a>, DESI co-spokesperson and an astrophysicist at the University of Waterloo in Canada. \u201cSo [a galaxy survey] can build up a history of the universe; we can build up slices that show us how the universe was at different ages.\u201d<\/p>\n In the coming months to years, cosmologists will pick apart the data, running observations against theoretical models. They will in particular scrutinize the validity of the cosmological constant, lambda (\u039b), which asserts that the universe\u2019s expansion is accelerating\u2014a widely accepted idea unexpectedly challenged by DESI.<\/p>\n Why they did it In 1998, astronomers studying distant supernovas found evidence that the universe was expanding at an ever-accelerating rate. But the arsenal of variables and equations scientists had at the time wasn\u2019t enough to prove it. If the universe just had some regular matter and gravitational force, its evolution would be determined by how fast that matter was expanding and the influence of gravity pulling it together, Percival explained.<\/p>\n \u201cTo get this acceleration of the expansion, you need something else to be present in the universe, whether it\u2019s a force or a new scalar field,\u201d he added. We\u2019ve termed this dark energy. But naming something doesn\u2019t tell us what it is.\u201d<\/p>\n Enter DESI. With information about millions and millions of galaxies, astronomers are free to run all sorts of cosmological tests using the datasets, which the DESI Collaboration publicly releases after some priming in-house. This isn\u2019t research that happens overnight. After all, the questions here address the universe\u2019s birth, how it\u2019s growing\u2014and, perhaps most importantly, how it might end.<\/p>\n Why they\u2019re a winner <\/p>\n DESI isn\u2019t the first instrument tasked to study dark energy. In fact, DESI members, including Percival and Klaus Honscheid<\/a>, the collaboration\u2019s co-instrument scientist, have ample experience working with similar projects, including DESI\u2019s forebears. But it certainly represents the ingenuity of scientists\u2014both in how the project was set up and in what it\u2019s accomplished in such a short amount of time.<\/p>\n \u201cTo get this acceleration of the expansion, you need something else to be present in the universe\u2026We\u2019ve termed this dark energy. But naming something doesn\u2019t tell us what it is.\u201d <\/p>\n DESI is installed on top of the Mayall 4-meter telescope<\/a> at Kitt Peak National Observatory in Arizona. Mayall launched in 1973, and considering the ever-growing sizes of telescopes (Vera Rubin\u2019s mirror is 8.4 meters wide), that might not sound so impressive. There\u2019s also the old bit of physics wisdom that claims bigger is better. But this telescope, which the community had \u201cmoved on [from],\u201d was perfectly suited for DESI\u2019s mission, Honscheid said, a physicist at Ohio State University.<\/p>\n \u201cThe way we do this is we have 5,000 little robots\u2014not the robots in science fiction, but these pencil-sized objects that can be remotely controlled, with optical fibers at the tip,\u201d Honscheid explained. \u201cYou know from imaging where a galaxy is, and then you move the fiber\u2019s tip to exactly that location; you do that with all 5,000 of them and then move on to the next exposure.\u201d<\/p>\n This level of precision is why, in a way, DESI is too good at its job. It created ripples of shock across cosmology even before the survey actually ended in April. Most famously, an analysis of data from its first three years didn\u2019t quite align with the standard model of cosmology<\/a>. In other words, there might be something deeply amiss with our understanding of the cosmological constant. If true, the consequences for cosmology would be nothing short of catastrophic and revolutionary.<\/p>\n<\/p>\n \u201cI think everybody was expecting that our data would match this model,\u201d Percival recalled. \u201cSo it was an incredible surprise when we first analyzed the data and found that it matched the [standard] model, which was good, but we found that it required parameters that were different from those we were expecting.\u201d<\/p>\n This particular finding falls slightly below the standard for declaring a statistically significant discovery, according to Honscheid. \u201cBut it\u2019s very enticing,\u201d he said. \u201cIt\u2019s a great hint.\u201d<\/p>\n What\u2019s next <\/p>\n The instrument is also still technically running (the day before his chat with Gizmodo, Honscheid had to tend to a glitch in the humidity control system; the issue was quickly solved). Currently, the plan is to have DESI study the night sky until about 2028. Then DESI will begin its second run, which will go until around 2035. There will definitely be upgrades, but the primary goal for now is to maintain its top-notch capabilities, Honscheid explained.<\/p>\n On the research side, scientists are actually not done with the dataset from DESI\u2019s first three years of operations\u2014simply because there is so much to study. That\u2019s partly why DESI opted for staggered data releases to open its observations to the community, as even partial DESI data could be of great interest to the community, Percival said. After all, astronomers\u2019 questions are as plentiful as the stars in the universe. That said, the five-year data dump is still being prepared, Percival explained. He added that there\u2019s always a lot of coding, mathematics, and science to find the \u201cmost robust way\u201d for folks to explore their interests.<\/p>\n \u201cWe tend to just say, \u2018Okay, here\u2019s how we analyzed a previous survey.\u2019 We\u2019ll do that with the new data,\u201d Percival said. \u201cBut in some ways, the problems we\u2019re facing are the same, but because we have so much data now, things we swept under the carpet 10, 15 years ago, we now do have to worry about, because our error bars are sufficiently small that now they\u2019ve become important.\u201d<\/p>\n \u201cThis problem of dark energy is sufficiently interesting, exciting, and big that [humanity has] put together a large number of very different experiments to really investigate it,\u201d Percival said. \u201cThe more experiments you have, the more different ways you have of measuring accelerated expansion\u2014the more you can believe any results that do come. There\u2019s Euclid<\/a>, which is coming up to its first data sample. There\u2019s Roman<\/a>, which is due for launch later this month\u2026 For sure, humans have always wanted to know their place in the universe.\u201d<\/p>\n The team <\/p>\n As of 2026, DESI reports<\/a> that the experiment \u201cbrings together more than 1,000 researchers, including 350 PhD students, 200 postdocs, and 150 undergraduates, from more than 70 institutions\u201d worldwide. The collaboration is managed by the U.S. Department of Energy\u2019s Lawrence Berkeley National Laboratory. The full list of DESI team members can be found here<\/a>.<\/p>\n![\"Typa](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/10\/typa-1a-supernova-remnant-g299-336x336.jpg\")
G299, a remnant of a Type Ia supernova, which clued astronomers into the accelerated expansion of the universe. Credit: NASA\/CXC\/U.Texas <\/p>\n![\"Desi](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/10\/desi-focal-plane.jpg\")
DESI\u2019s focal plane, which carries the 5,000 robotic positioners. Credit: Marilyn Sargent\/The Regents of the University of California, Lawrence Berkeley National Laboratory ![\"Nicholas](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/10\/mayal-4-meter-telescope-kitt-peak-interior-1280x855.jpg\")
The interior of the U.S. National Science Foundation Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory. Credit: DESI Collaboration\/DOE\/KPNO\/NOIRLab\/NSF\/AURA\/M. Sargent (Berkeley Lab) <\/p>\n![\"Milky](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/10\/milky-way-over-kitt-peak-1280x1018.jpg\")
The band of the Milky Way stretches across the sky above the Kitt Peak National Observatory. Credit: KPNO\/NOIRLab\/NSF\/AURA\/P. Hor\u00e1lek (Institute of Physics in Opava) <\/p>\n