Here’s the best timeline yet for the Milky Way’s big events

Our galaxy formed its original disk 2 billion years before its stellar halo

photo of the Milky Way with purple hues in the sky above the Large Sky Area Multi-Object Fiber Spectroscopic Telescope in China

The Milky Way arches over the Large Sky Area Multi-Object Fiber Spectroscopic Telescope in China, one of the observatories whose data has revealed that our galaxy began forming a disk of stars surprisingly fast after the Big Bang.

Yingwei Chen

A new analysis of nearly a quarter million stars puts firm ages on the most momentous pages from our galaxy’s life story.