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Across five years of sky watching, the Dark Energy Spectroscopic Instrument (DESI<\/a>), a telescope-mounted galaxy mapper, gathered the evidence behind that record.<\/p>\n Using those measurements, Michael Levi, DESI director at Lawrence Berkeley National Laboratory (Berkley Lab<\/a>), connected the map to the universe\u2019s hidden driver.<\/p>\n Designers expected 34 million galaxies and quasars, extremely bright galaxy cores powered by black holes, before observations passed 47 million.<\/p>\n That extra reach gives researchers a sharper test of the hidden energy controlling the universe\u2019s long-term future, not just its past.<\/p>\n Why expansion matters<\/p>\n Astronomers call that hidden driver dark energy<\/a> , the force tied to faster cosmic expansion. As space expands, galaxies drift apart, and dark energy appears to push that widening pace harder over time.<\/p>\n NASA estimates that dark energy fills about 68% to 70% of the cosmos, while ordinary matter, the stuff in atoms, accounts for roughly five percent.<\/p>\n Future forecasts depend on whether that force stays steady, weakens, or changes in a way current physics cannot yet explain.<\/p>\n Light becomes distance<\/p>\n For each target, DESI measured redshift, the stretching of light that reveals how fast an object recedes.<\/p>\n A published instrument<\/a> description explains how ten spectrographs, devices that split light by color, turned faint signals into measurable positions.<\/p>\n With millions of distances stacked together, the flat sky became a 3D record reaching back about 11 billion years of history.<\/p>\n Even that reach cannot show every region, because our own galaxy blocks some faint background light from beyond it.<\/p>\n Patterns hold clues<\/p>\n Galaxy positions matter because gravity pulls matter into clusters, leaving patterns that expansion stretches across deep cosmic time.<\/p>\n Cosmologists measure baryon acoustic oscillations<\/a>, ancient spacing patterns in matter, to compare early structure with later structure.<\/p>\n A three-year analysis found that those patterns fit standard expectations, yet fit better when dark energy can change.<\/p>\n That result raises pressure on a familiar idea, although a hidden data problem could still weaken it.<\/p>\n Certainty under pressure<\/p>\n A familiar idea is the cosmological constant, Einstein\u2019s fixed-energy<\/a> term for empty space.<\/p>\n In that view, dark energy never changes, so cosmic expansion should follow one steady long-term path.<\/p>\n DESI\u2019s newer measurements reduce some tensions, yet they do not erase the case for time-changing dark energy.<\/p>\n Stronger proof will require the completed map to survive checks against exploding stars and older light from the early universe.<\/p>\n At the Kitt Peak National Observatory, an Arizona mountaintop observatory, DESI worked through heat, weather, and shutdowns.<\/p>\n Its robotic fiber positioners<\/a>, tiny arms that aim light-carrying fibers, retargeted the sky about every 10 to 20 minutes.<\/p>\n A 2022 wildfire cut power and internet service for months, but crews recovered enough observing nights to finish early.<\/p>\n After the planned survey ended, the team kept DESI observing through 2028 instead of parking the instrument and waiting.<\/p>\n That extension aims to expand how much of the sky<\/a> the survey covers, increasing its reach by about one-fifth.<\/p>\n Harder regions sit near the Milky Way\u2019s bright plane or lower in the southern sky, where atmosphere interferes.<\/p>\n More coverage can tighten expansion tests, but it also brings messier light that analysts must handle carefully before trusting.<\/p>\n Nearby darkness too<\/p>\n The same observations also recorded more than 20 million nearby stars inside and around the Milky Way.<\/p>\n Those stars help map dark<\/a> matter, invisible mass detected by gravity, because their motions reveal hidden pull.<\/p>\n Small dwarf galaxies, low-mass companions of larger galaxies, trace that pull especially well when gravity distorts their stars.<\/p>\n This nearby work cannot name dark matter\u2019s particles, but it can narrow where theorists should look for evidence.<\/p>\n Mapping dark energy with DESI<\/p>\n The completed dataset now moves into processing, where scientists check positions, remove errors, and prepare public measurements.<\/p>\n DESI\u2019s first public data release<\/a> covered 13 months of observations and already held 18.7 million dependable distances to cosmic objects.<\/p>\n Full five-year dark energy results are expected in 2027, after the collaboration tests the map\u2019s hardest claims against all observing years.<\/p>\n Until then, the strongest finding is not an answer, but a much better way to ask for one with evidence.<\/p>\n A larger map now joins sharper distance measurements, tougher model tests, and new targets that stretch beyond the original plan\u2019s limits.<\/p>\n \u201cWe don\u2019t know what we\u2019ll find, but we think it\u2019ll be pretty exciting,\u201d said Levi.<\/p>\n<\/p>\n The study is published in Physical Review D<\/a>.<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.<\/p>\n Check us out on EarthSnap<\/a>, a free app brought to you by Eric Ralls<\/a> and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"Scientists have finished the largest high-resolution 3D map of the universe, logging more than 47 million galaxies and…\n","protected":false},"author":2,"featured_media":645891,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[64,63,128,285],"class_list":["post-645890","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-au","tag-australia","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/645890","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=645890"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/645890\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/645891"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=645890"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=645890"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=645890"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Star](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/05\/desi-Mayall-Telescope_star-trails_Luke-Tyas_Berkeley_1s.webp.webp\")
<\/a>Star trails over the Mayall Telescope that houses DESI, where the biggest 3D map of the universe was created. Credit: Luke Tyas\/Berkeley Lab and KPNO\/NOIRLab\/NSF\/AURA. Click image to enlarge.Incredible performance by DESI<\/p>\n