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Astrophysicists Uncover 76% of Universe's Hidden Matter

6/20/2025

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Summary

Story summary

Astronomers from Harvard & Smithsonian and Caltech have made a groundbreaking discovery: 76% of the Universe's baryonic matter resides in the intergalactic medium. Utilizing fast radio bursts (FRBs) to map its distribution, this revelation sheds light on the elusive "missing baryon problem," deepening our understanding of cosmic structure and galaxy formation. The findings are detailed in Nature Astronomy.

History

Historical Context

In 1978, NASA's Cosmic Background Explorer (COBE) satellite confirmed cosmic microwave background radiation, revealing that dark energy and dark matter constitute about 99% of the universe's energy density. Recent studies by Harvard & Smithsonian and Caltech found that 76% of baryonic matter exists in the intergalactic medium, addressing the "missing baryon problem" and enhancing our understanding of cosmic structure and galaxy formation.

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Story summary

Astronomers from Harvard & Smithsonian and Caltech have made a groundbreaking discovery: 76% of the Universe's baryonic matter resides in the intergalactic medium. Utilizing fast radio bursts (FRBs) to map its distribution, this revelation sheds light on the elusive "missing baryon problem," deepening our understanding of cosmic structure and galaxy formation. The findings are detailed in Nature Astronomy.

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