 The coma supercluster is a nearby supercluster of galaxies that includes the famous coma cluster Able 1656. The supercluster is located 300 million light years from Earth. It is roughly spherical, about 20 million light years in diameter, and contains more than 3,000 galaxies. Being one of the first superclusters to be discovered, coma supercluster helped astronomers understand the large-scale structure of the universe.