What did the James Webb Space Telescope discover about the earliest galaxies in the universe?

The answer

The James Webb Space Telescope's deep infrared observations in 2023-2024 revealed galaxies existing just 290-350 million years after the Big Bang (at redshifts above 13), shattering previous records and challenging fundamental models of galaxy formation. The JADES (JWST Advanced Deep Extragalactic Survey) discovered galaxies at redshift 14.3 - meaning their light has traveled for over 13.5 billion years. Most shockingly, these ancient galaxies appear far more massive, chemically enriched, and structurally organized than theoretical models predicted possible so soon after the Big Bang. Some contain dust, heavy elements, and even spiral structures that were thought to require billions of years to develop. These discoveries suggest that star formation began almost immediately after the universe's 'dark ages' ended, forcing astrophysicists to fundamentally revise their understanding of how quickly cosmic structures assembled in the infant universe.