Analysis of data from the Gaia satellite shows a powerful burst of star formation – a stellar baby boom – in our Milky Way galaxy 2 to 3 billion years ago. This single burst might have created half the stars in the galaxy’s flat disk.
The Andromeda galaxy is the nearest large spiral to our Milky Way. Astronomers have suspected for some time it will eventually collide with our Milky Way. Now – thanks to the Gaia satellite – they know more.
We think of globular clusters as being scattered far from the galaxy’s central regions, in the great spherical halo of our Milky Way. But astronomers are finding them much closer to the galactic center.
Astronomers found a snail-shaped substructure of stars in our larger Milky Way galaxy. It indicates the Milky Way is still enduring the effects of a near-collision that set millions of stars moving like ripples on a pond.