“Heracles” –Fossil Galaxy Seeded the Infant Milky Way With Alien Stars

Milky Way Halo



Astronomers have excavated a galactic tomb –a stunning picture of our home galaxy’s successive mergers with neighboring galaxies. Recent discoveries by the Apache Point Observatory Galactic Evolution Experiment (APOGEE) revealed the “archaeological” record embedded in hundreds of thousands of stars that unveiled the assembly history and evolution of our Milky Way Galaxy.