Study reveals how the Milky Way's disk formed

Analysis of Gaia DR3 data shows the Milky Way's disk formed in two stages: about 10.85 billion years ago its vertical settling rate changed sharply. The disk thinned from 1.26 to 0.5 kpc in just 2 billion years, then flattened much more gradually.

• Disk thickness fell from 1.26 to 0.5 kpc in about 2 billion years
• The settling rate break occurred roughly 10.85 billion years ago
• Youngest stellar populations show a vertical scale height of about 0.1 kpc
• The work is based on Gaia Data Release 3 from June 2022