Astronomers Find Universe’s Missing Ordinary Matter

Astronomers from multiple research teams now believe they have located the universe's long-missing ordinary, or baryonic, matter, which accounts for about 15% of the universe's mass. By using advanced tools such as the Dark Energy Spectroscopic Instrument and analyses of the cosmic microwave background, scientists identified vast, diffuse halos of ionized hydrogen gas encircling galaxies, extending up to five times farther than previously estimated. These nearly invisible halos appear to resolve the longstanding discrepancy between predicted and observed baryonic matter. The findings support theories that supermassive black holes can expel gas to much greater distances than previously thought. The results remain under peer review, but the discovery could be pivotal for understanding galaxy evolution and the universe's overall composition. Enhanced observational techniques played a crucial role in this breakthrough.