The End of the Cosmic Dawn: Settling a Two-Decade Debate
A group of astronomers has robustly timed the end of the epoch of reionization of the neutral hydrogen gas to approximately 1.1 billion years
a long period when the Universe was filled with neutral gas alone without any sources of light.
the Universe has undergone different phases. During the first 380,000 years after the Big Bang,
With the advent of the first stars and galaxies roughly 100 million years later,
Observing those first stars and galaxies directly is beyond the capabilities of contemporary telescopes
They are simply too faint to obtain useful data within a reasonable amount of time.
next-generation facilities like ESO’s Extremely Large Telescope (ELT) or the James Webb Space Telescope may struggle with such a task.