The Digital Press

Astronomers have used fast radio bursts (FRBs) to locate over three-quarters of the universe’s ordinary matter, which exists as hot, diffuse gas between galaxies. This discovery solves the long-standing "missing baryon problem" by mapping the distribution of baryonic matter across cosmic structures.

Why it matters: Identifying the universe’s missing ordinary matter clarifies the composition and structure of the cosmos, deepening our understanding of galaxy formation.

The big picture: FRBs provide a new method to study the intergalactic medium, confirming simulations that baryons cycle between galaxies and vast cosmic gas.

Stunning stat: About 76% of baryonic matter lies in the intergalactic medium, 15% in galaxy halos, and only a small fraction in stars or cold gas.

Commenters say: Many note the distinction from dark matter, question implications for cosmic distance measurements, and discuss what "hot" gas means in this context.