Harvard & Smithsonian (CfA) and Caltech, for the first time, detected the universe’s missing ordinary matter using powerful cosmic signals known as Fast Radio Bursts (FRBs). 

• Previously, scientists have known that at least half of the universe's ordinary, or baryonic matter was unaccounted for. 

Distribution of Ordinary Matter Across the Universe

• 76% in intergalactic medium (IGM) (the thin gas between galaxies).
• 15% in galaxy halos (outer regions surrounding galaxies)
• 9% within galaxies (consist of stars, planets, and vast clouds of gas and dust, all bound together by gravity).

About Fast Radio Bursts (FRBs) 

• Definition: FRBs are blasts of electromagnetic radiation in the form of radio waves usually emanating from galaxies beyond our own.
  • FRBs have durations ranging from milliseconds to just a few seconds.

How Fast Radio Bursts (FRBs) Helped Solve the Mystery?

• FRBs acted as "cosmic flashlights". As FRBs travel through space, they:
  • Disperse into different wavelengths, like a prism spreading sunlight.
  • The degree of dispersion reveals the amount of matter in their path.
• FRBs provided the first direct measurement of matter distribution across the cosmic web & established themselves as a reliable cosmological probe.