The Coma Supercluster (SCl 117) is a nearby supercluster

Supercluster

Superclusters are large groups of smaller galaxy groups and clusters and are among the largest known structures of the cosmos. They are so large that they are not gravitationally bound and, consequently, partake in the Hubble expansion.-Existence:...

 of galaxies comprising the Coma Cluster (Abell 1656) and the Leo Cluster

Leo Cluster

The Leo Cluster is a galaxy cluster about 330 million light-years distant in the constellation Leo. Along with the Coma Cluster, it is one of the two major clusters comprising the Coma Supercluster-External links:...

 (Abell 1367). Located 300 million light-year

Light-year

A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...

s from Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

, it is in the center of the Great Wall

Great Wall (astronomy)

The Great Wall , sometimes specifically referred to as the CfA2 Great Wall, is one of the largest known super-structures in the Universe...

. The Coma Supercluster is the nearest massive cluster of galaxies to our own Virgo Supercluster

Virgo Supercluster

The Virgo Supercluster or Local Supercluster is the irregular supercluster that contains the Virgo Cluster in addition to the Local Group, which in turn contains the Milky Way and Andromeda galaxies. At least 100 galaxy groups and clusters are located within its diameter of 33 megaparsecs...

. It is roughly spherical, about 20 million light-years in diameter and contains more than 3,000 galaxies. It is located in the constellation Coma Berenices

Coma Berenices

Coma Berenices is a traditional asterism that has since been defined as one of the 88 modern constellations. It is located near Leo, to which it formerly belonged, and accommodates the North Galactic Pole...

. Being one of the first superclusters to be discovered, the Coma Supercluster helped astronomer

Astronomer

An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...

s understand the structure of the universe.