Astronomers find universe's "missing" matter after long search

June 18, 2025

Evrim Yazgin
Cosmos science journalist


Normal matter makes up about a quarter of all the matter in the universe but it turns out that a good portion of it has been hiding from astronomers for decades. New research published in Nature Astronomy shows how astronomers have found this “missing” matter.

Observations of the gravitational forces in galaxies were used to measure the amount of normal, or visible, matter. The rest is dark matter.

At least half of the visible matter – also called baryonic matter, composed mostly of protons – was unaccounted for according to astronomical observations. Astronomers had tried X-ray emission and ultraviolet observations of distant quasars (the bright material around supermassive black holes) to try and account for the missing matter.

Astronomers looked in the spaces between galaxies, hoping to find hints of thin, warm gas that would otherwise be invisible to most telescopes.

The new research uses fast radio bursts (FRBs) to expand this search. FRBs themselves are unusual and not well understood. They are short, bright bursts of radio waves from distant galaxies. The source of FRBs is not yet known.

In 2020, astronomers showed that FRBs could help find baryonic matter in the universe. But only now have astronomers been able to use this data to pinpoint the location of the matter.

More:
https://cosmosmagazine.com/space/astrophysics/missing-matter-universe-astronomers/