A Stubborn Question Answered: New Research Reveals How the Milky Way's Disk Formed
Figuring out how the Milky Way's thin and thick disks formed is a tough question in astronomy. It relies on determining individual stellar ages accurately. Gaia was pretty good at that, and new research based on its data may have found the answer.
We haven't written up this one. Universe Today has the full story — the link below goes straight to it.