Much of the universe's regular "baryonic" matter is spread through intergalactic space and in diffuse halos around galaxies, researchers proposed after studying the behavior of fast radio bursts emitted from deep space.

Decades ago, astronomers estimated that “ordinary” matter (basically everything that isn’t dark matter or dark energy) makes up 5% of the universe. There was just one problem—they had no idea where most of it was.

A new landmark study has pinpointed the location of the universe's "missing" matter, and detected the most distant fast radio burst (FRB) on record. Using FRBs as a guide, astronomers at the Center for Astrophysics | Harvard & Smithsonian (CfA) and Caltech have shown that more than three-quarters of the universe's ordinary matter has been hiding in the thin gas between galaxies,