The Milky Way Galaxy, the home galaxy of Earth and its solar system with a single star, contains 100-400 billion stars and is estimated to have at least 50 billion planets, 500 million of which could be located in the habitable zone of their parent star. If that doesn’t blow your mind, the Milky Way is only one of about 200 billion galaxies in the observable universe. Kinda puts it all in perspective, eh?