James Webb Space Telescope uncovers record‑distant galaxies and unexpected early‑universe chemistry

The James Webb Space Telescope (JWST), launched on 25 December 2021 by NASA, ESA and CSA, has delivered the deepest infrared images of the cosmos. Its 12.5‑hour observation of the galaxy cluster SMACS 0723, situated about 4.6 billion light‑years from Earth, revealed galaxies formed roughly 13.1 billion years after the Big Bang.

In 2024 JWST identified the most distant known galaxies: JADES‑GS‑z14‑0, dating to about 300 million years after the Big Bang, and MoM‑z14, dated to roughly 280 million years post‑Big Bang. These objects are larger and brighter than models predicted. Spectroscopic analysis also detected heavy elements such as nitrogen, carbon, oxygen and neon in these early galaxies, challenging the view that only hydrogen, helium and trace lithium existed at that epoch.

The telescope’s capabilities have also enabled the discovery of the ultra‑bright star Earendel, thought to be a key driver in ending the universe’s “cosmic dark ages.” JWST’s observations are prompting astronomers to revise theories of early star and galaxy formation.

These findings underscore JWST’s role as the most powerful space observatory to date, providing unprecedented detail that reshapes our understanding of the early universe.