~380,000 years to a few hundred million years after the Big BangReputable sourceWell documented
The Cosmic Dark Ages
On the timeline · around ~380,000 years to a few hundred million years after the Big Bang · Cosmic Dawn
What happened
After the cosmic microwave background was released, the universe entered the 'Dark Ages' — a long, starless era filled with neutral hydrogen gas and no sources of visible light.
Why it matters
For hundreds of millions of years the cosmos was truly dark, until gravity slowly gathered gas dense enough to ignite the very first stars.