James Webb Telescope Discovers Most Distant Galaxy From Just 300 Million Years After the Big Bang

In May 2024, the James Webb Space Telescope (JWST), operated by NASA, discovered the most distant galaxy ever observed, named JADES-GS-z14-0, as part of its deep space survey called JADES. The light from this galaxy has taken approximately 13.5 billion years to reach us, so we are viewing it as it appeared about 300 million years after the Big Bang, during the “cosmic dawn” era when the first stars and galaxies were forming.

Discovery of JADES-GS-z14-0

According to NASA, the infrared camera (NIRCam) on the James Webb Space Telescope (JWST) took the image of JADES-GS-z14-0 in ultradeep exposures of a very small region of the sky. Follow-up spectroscopy (NIRSpec) determined a redshift of approximately 14.3, making it the most distant galaxy known at the time. This redshift indicates an age of approximately 300 million years and a distance of 13.5 billion light-years. This broke the record for cosmic distance by about 100 million years. The observation (announced in early 2024) demonstrated the capability of JWST to observe galaxies at distances further back in time than ever before.

A Surprisingly Bright, Mature Galaxy

Astronomers were surprised to see that JADES-GS-z14-0 was very bright and evolved for its time. Scientists describe it as “unexpectedly bright and chemically complex.” It holds about half a billion suns' worth of stars, which is indicative of very active star formation. What is particularly interesting is that the mid-infrared observations made by JWST revealed a strong oxygen signal, which indicated that several generations of stars had already lived and died. (Substances heavier than helium are known as “metals” in the field of astronomy. This indicates very active metal production.) Most theories had suggested that the first galaxies would be small, faint, and very metal-poor.