The Milky Way begins forming
Our own galaxy starts making stars roughly 800 million years after the Big Bang.
- When
- Known to
- ± 200 million years
- Era
- Reionisation, Stelliferous
Star formation begins in the population that becomes the Milky Way's thick disk and halo. Gaia measurements of individual stellar ages and chemistry let this history be reconstructed star by star, and they place the beginning of our galaxy's assembly within the first billion years. The oldest stars still orbiting the Milky Way today date from this period.