The Milky Way Devoured the Loki Galaxy

The Milky Way was not always the cosmic giant we see today; it grew by devouring its neighbors. In today’s episode, we investigate a groundbreaking study published in the Monthly Notices of the Royal Astronomical Society that identifies the remnants of an ancient dwarf galaxy named Loki. Astronomers acting as "detectives of the universe" have used data from the Gaia telescope to track 20 mysterious "metal-poor" stars hidden deep within the galactic disk—a region usually too crowded with dust and young stars to see such ancient relics.We break down how these stars, which are over 10 billion years old, share a unique chemical "fingerprint" suggesting they all originated from the same galactic meal. We also explore why the galaxy was named after the Norse god of mischief: its stars move in confusing, opposing orbital patterns that challenged everything we knew about galactic mergers. Join us as we discuss how the Loki merger was a transformative event on the scale of the famous Gaia-Sausage-Enceladus collision, potentially resetting the history of our home galaxy.Become a supporter of this podcast: https://www.spreaker.com/podcast/scitech-brief--6846358/support.This episode includes AI-generated content.