ESA's Gaia mission has made a major breakthrough in unravelling the formation history of the Milky Way. Instead of forming alone, our Galaxy merged with another large galaxy early in its life, around 10 billion years ago. The evidence is littered across the sky all around us, but it has taken Gaia and its extraordinary precision to show us what has been hiding in plain sight all along. ESA's Gaia mission has made a major breakthrough in unravelling the formation history of the Milky Way. Inst...| sci.esa.int
The Sagittarius dwarf galaxy in Gaia's all-sky view| sci.esa.int
Informatoin on the Gaia Data Release Scenario| Gaia
ESA's star mapping mission, Gaia, has shown our Milky Way galaxy is still enduring the effects of a near collision that set millions of stars moving like ripples on a pond.| sci.esa.int