Unveiling the Secrets of the Universe's First Light.

The mystery of how the universe transformed from opaque to transparent during the Era of Reionization has been solved by a team of researchers led by Simon Lilly of ETH Zürich in Switzerland, using the James Webb Space Telescope. The team focused on quasar J0100+2802 and observed how the light from the quasar behaved as it passed through gases along the path from J0100+2802 to the telescope's instruments. The results revealed that the galaxies were each surrounded by an envelope of hot, ionized, transparent gas up to 2 million light years in radius, which was responsible for bringing about the Era of Reionization.