Penticton, Canada: Scientists using Canada’s Canadian Hydrogen Intensity Mapping Experiment (CHIME) have detected the faint radio glow of hydrogen from a period when the universe was about five billion years old, opening a new way to study how cosmic structures formed and how the universe has expanded over time.

First Standalone Detection

The breakthrough is significant because CHIME detected the hydrogen signal using its own observations, without depending on data from separate galaxy surveys.

Hydrogen is the most abundant element in the universe, and its radio emission can act as a tracer of how matter is distributed across enormous regions of space. Mapping that distribution allows researchers to investigate the evolution of the universe and the forces influencing its expansion.

Looking Billions of Years Into the Past

The detected signal comes from hydrogen that existed billions of years ago. Researchers extracted the extremely faint emission from 94 nights of observations collected by CHIME in 2019.

The signal was buried beneath radio noise from the cosmos, human technology and the telescope itself. Scientists spent more than a year testing the result before concluding that the signal was genuine.

Hydrogen Creates a New Cosmic Map

Rather than observing individual galaxies, CHIME measures the combined radio emission from hydrogen spread throughout large volumes of space.

According to the research team, the observations indicate that roughly 2% of the hydrogen in the studied period was in neutral atomic form. The distribution of that hydrogen provides information about how matter was clustered across the universe.

New Possibilities for Dark Energy Research

One of the major goals behind the experiment is to improve scientists’ understanding of dark energy, the poorly understood phenomenon associated with the accelerating expansion of the universe.

By tracking how hydrogen is distributed at different distances and cosmic ages, astronomers can eventually use the technique to study the history of cosmic expansion.

The new observation does not by itself settle the nature of dark energy. Instead, it demonstrates that hydrogen intensity mapping can provide an independent observational method for future cosmological studies.

CHIME Surveys the Northern Sky

CHIME is located near Penticton in British Columbia and is designed to survey the northern sky as Earth rotates.

The telescope is operated through a collaboration involving the University of British Columbia, McGill University, the University of Toronto and the Dominion Radio Astrophysical Observatory, along with other research partners.

More Data Could Reveal Earlier Cosmic History

The current discovery represents only a small portion of CHIME’s available observations. Researchers now have nearly seven years of data and are working to extend their analysis further back in cosmic history.

Future measurements could allow scientists to examine hydrogen from an even earlier stage, potentially when the universe was only about three billion years old.

A New Window Into the Universe

The successful detection marks an important step for radio-based cosmology. Instead of relying exclusively on traditional galaxy surveys, scientists can now use the faint radio signature of hydrogen itself to investigate the large-scale structure of the universe.

As more CHIME data are analyzed, researchers hope the technique will provide new information about galaxy formation, cosmic expansion and the mysterious physics associated with dark energy.