A Canadian radio telescope has made its first standalone detection of hydrogen from when the universe was about five billion years old, creating a new way to trace cosmic expansion and investigate dark energy.
The Canadian Hydrogen Intensity Mapping Experiment, or CHIME, located near Penticton, British Columbia, detected the faint 21-centimeter radio signal using only its own observations. The signal comes from an era roughly nine billion years in the past, when the universe was transitioning toward its current period of accelerated expansion. Researchers analyzed 94 nights of CHIME observations collected in 2019 and measured the signal through an autocorrelation technique, rather than comparing it with galaxy surveys from other telescopes.
The detection reached a significance of 12.5 sigma, providing strong evidence that the signal was genuine. Hydrogen intensity mapping allows scientists to chart how matter was distributed across large regions of space, providing a record of how cosmic structures and expansion changed over time. The approach could be faster, less expensive and able to cover more of the universe than conventional galaxy surveys.
Scientists caution that the result does not directly solve the mystery of dark energy, but it validates an independent tool that could test competing explanations for the universe’s accelerating expansion. The finding was reported by ScienceDaily on October 9, 2026, following the study’s publication and institutional announcements in late September.