In the first few minutes, nuclear fusion created the first light elements: hydrogen, helium, and traces of lithium. Temperatures were billions of degrees. The soup was too hot for atoms to exist, so it remained a plasma for hundreds of thousands of years. This primordial mix laid the groundwork for stars and galaxies. Studying this helps scientists understand elemental abundances.
The primordial soup matters because it explains the composition of matter in the universe today.
It also provides constraints for particle physics and cosmology models.
The universe’s first minutes forged the elements that make up stars, planets, and you.
European Space Agency [esa.int]