Ancient tribes and cultures would look up in amazement and wonder at what they described as a milky river; as a path on an infinite journey. What we know today as the Milky Way, a typical spiral galaxy 100,000+ light years across with over 200 billion stars and enough cosmic gas and dust to make billions more. Forming 13.6 billion years ago, the Milky Way is an average galaxy in a group of over 54 galaxies called, the Local Cluster, which in turn is apart of the Virgo Supercluster, a massive group of galaxies that contains over 100 different galaxy clusters.
Only 10 percent of the Milky Way contains mass, with the rest being made up of dark matter and a phenomenon called dark energy, a force pushing on matter and mysteriously accelerating the expansion of the universe. The center of the Milky Way is 27,000 lightyears away and home to a supermassive black hole, 4 million times the mass of our Sun. Black holes cannot be seen or photographed because light cannot escape its extreme gravity, but scientists can test the gravitational pull on nearby objects to get an estimate of its mass. The gas and dusk surrounding our galactic center is so dense that light cannot pass through, which is why astronomers use infrared telescopes to capture light beyond the visible spectrum. Relatively alone, the Milky Way’s nearest star neighbor, Proxima Centauri, is 4.22 lightyears away while the closest galaxy, Andromeda, is 2.5 million light years away.