The Milky Way Devoured a Small Galaxy — 500 Million Suns' Worth — Soon After It Was Born
Big galaxies didn't start out big. Hubble and Gaia teamed up to precisely measure 39 star clusters buried deep in the Milky Way, revealing the fossil remains of a small galaxy called LKH that our galaxy swallowed roughly 11.8 billion years ago. SORABUMI explains the evidence that galaxies grow by eating their neighbors.