James Webb: A Cosmic Time Machine

James Webb isn’t just taking pretty pictures — it’s a time machine. It has already spotted

galaxies from less than 300 million years after the Big Bang, shining brighter

and bigger than many models expected, like the record-setting JADES-GS-z14-0. And Webb didn’t

just “see” early galaxies — it caught clues about the Universe’s makeover: evidence that reionization

(the event that ended the cosmic “dark ages”) may have been underway astonishingly early,

with distant galaxies carving out bubbles in primordial hydrogen. Closer to home, Webb is reading

alien skies like barcodes. It’s detected methane and carbon dioxide in the atmosphere

of K2-18 b, and it’s even found strong evidence for a thick atmosphere on an ultra-hot