The First Galaxies

What happened

Within the first billion years, stars gathered by gravity into the first galaxies. The James Webb Space Telescope, built to peer into this era, has detected galaxies that existed just a few hundred million years after the Big Bang — one, JADES-GS-z13-1, seen as it was only about 330 million years after the beginning.

Why it matters

Galaxies are the universe's basic building blocks of structure. Webb's discovery that large galaxies formed surprisingly early is reshaping our understanding of how the cosmos assembled.

Sources

• NASA Science. Webb — The Early Universe · Reputable source