The early universe wasn’t nearly as pristine as scientists thought

JWST revealed that galaxies were spreading carbon, oxygen, and other heavy elements through space just 500 million years after the Big Bang. The surprising discovery suggests the young universe became chemically enriched much earlier than expected, potentially erasing traces of its very first stars. The early universe wasn’t nearly as pristine as scientists thought.

The early universe wasn’t nearly as pristine as scientists thought Science News from research organizations The early universe wasn’t nearly as pristine as scientists thought JWST reveals that some of the universe’s first galaxies were already spreading the ingredients for planets and life across the cosmos just 500 million years after the Big Bang. The orange structures represent metal-enriched gas being expelled from the galaxy, illustrating how young galaxies began dispersing heavy elements into their surroundings within the Universe’s first 500 million years. The visualization is based on publicly available FIRE-2 cosmological simulation data and is not a direct telescope image.

Astronomers have generally expected that much of the gas around these young galaxies would still have been nearly pristine, consisting mostly of hydrogen and helium, the basic elements that dominated the newborn cosmos. New evidence suggests that picture may be incomplete. A study led by astronomers at the University of Arizona and published in Nature Astronomy indicates that early galaxies were already sending heavier elements such as carbon and oxygen into surrounding space much sooner than expected.

"We observed that heavy elements escaped from galaxies very, very early in cosmic time," said Yongda Zhu, first author of the paper and postdoctoral researcher at the U of A Department of Astronomy and Steward Observatory.