Andromeda Galaxy A massive spiral million light-years away, over twice the diameter of our own Milky Way, it's the largest nearby galaxy. Andromeda's population of bright young blue stars lie along its sweeping spiral arms. by Spitzer Space Telescope
Milky Way. "Every star we see in the sky is part of the Milky Way, but a brighter center exists some light-years away. The Milky Way is about light-years in diameter and contains 200 to 400 billion stars.