What did the JWST deep field images reveal about the early universe?

The answer

The James Webb Space Telescope's first deep field image, released on July 12, 2022, captured galaxy cluster SMACS 0723 as it appeared 4.6 billion years ago, using gravitational lensing to magnify galaxies behind it from the first billion years of cosmic history. The image required only 12.5 hours of exposure, compared to weeks for Hubble's similar images. Subsequent deep field observations revealed thousands of previously invisible galaxies at redshifts above 10, existing less than 500 million years after the Big Bang. JWST's JADES survey discovered galaxies at redshift 14.3 - just 290 million years post-Big Bang. These unexpectedly mature early galaxies, containing dust, metals, and organized structures, challenge existing models of galaxy formation and suggest star formation began almost immediately after conditions permitted.