Researchers led by Carme Gallart from the Instituto de Astrofísica de Canarias in Spain published their findings in Nature Astronomy on Monday. They found out that ten billion years ago, the Milky Way met Gaia-Enceladus, another galaxy, and consumed it.
Scientists have had evidence for a while that the Milky Way saw a major merger in its past. Even without direct evidence here in our home galaxy, scientists know that galaxy collisions are commonplace in the universe. These mergers are the major way that galaxies grow and evolve. But this is the first time that astronomers have been able to pinpoint the ages of different stellar populations within the Milky Way accurately enough to pin down when this merger occurred, and how exactly it affected our home galaxy.
So how did they pinpoint the time when this merging occurred? Find out on Discover Magazine.
(Image Credit: Koppelman, Villalobos and Helmi/NASA/ESA/Hubble)