'Groupie' galaxies orbiting Milky Way tell us about dark matter, how galaxy formed
Monday, May 18, 2020 - 08:30
in Astronomy & Space
We live in a big-city galaxy. The Milky Way is so big it has satellite galaxies that orbit it, just as the Moon orbits the Earth. These arrangements tell us a great deal about the secrets of the universe—from how galaxies form to the mysterious nature of dark matter.