Reionisation Epoch
Ultraviolet light from early stars reionises cosmic hydrogen.
The reionisation epoch was the period when the first stars and galaxies emitted enough high-energy light to reionise the hydrogen gas filling the universe. After the long “dark age,” this radiation cleared the fog-like neutral gas, making the universe transparent to light and allowing modern cosmic structures to form fully.
By Harleah Fonteyn 5/12/25
[frame]: cosmic stella epochs