Astronomers Just Solved the Mystery of the Universes Missing Matter

Published: Monday, June 16, 2025 at 3:10 pm

Astronomers Uncover the Universe's Missing Matter

Astronomers have made a significant breakthrough in understanding the composition of the universe, solving a long-standing mystery about the location of ordinary matter. For decades, scientists have known that ordinary matter, which includes everything that isn't dark matter or dark energy, accounts for approximately 5% of the universe. However, the whereabouts of a significant portion of this matter remained unknown.

A new study, published in *Nature Astronomy*, reveals that the missing baryonic matter, composed of protons and neutrons, primarily exists as hot, low-density gas between galaxies. Researchers from the Center for Astrophysics Harvard & Smithsonian (CfA) and the California Institute of Technology (Caltech) utilized fast radio bursts (FRBs) to track down this elusive matter. FRBs are brief, intense radio signals originating from distant galaxies. As these signals travel through the intergalactic gas, they slow down. By measuring this decrease in speed, the team could determine the amount of gas the signal had traversed.

The team analyzed 60 FRBs, ranging from galaxies 11.74 million to 9.1 billion light-years away. Their findings indicate that approximately 76% of all baryonic matter resides in the intergalactic medium (IGM), the space between galaxies. Another 15% is found in galaxy halos, with a small fraction in stars and cold galactic gas. This distribution aligns with previous cosmological simulations, but this study provides direct observational evidence.

The research also sheds light on the dynamic nature of matter distribution. The study suggests that supermassive black holes and exploding stars play a crucial role in regulating the distribution of baryonic matter, pushing gas out of galaxies and into the IGM. This process, known as feedback, helps to cool the cosmic environment.

This discovery marks a significant advancement in our understanding of the universe's structure and composition. With the anticipated increase in the detection of FRBs, scientists are optimistic about uncovering further cosmic secrets.

BNN's Perspective: This research is a testament to the power of innovative observational techniques. While the findings are highly technical, the implications are clear: we are gaining a more complete picture of the universe's fundamental building blocks. The use of FRBs to probe the otherwise invisible intergalactic medium is a clever and promising approach. This study underscores the importance of continued investment in astronomical research, as it continues to yield surprising and valuable insights into the cosmos.

Keywords: missing matter, baryonic matter, fast radio bursts, FRBs, intergalactic medium, IGM, galaxies, astronomers, universe, cosmology, astrophysics, research, science, space

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