The Milky Way galaxy is not located inside the Virgo Cluster, but it is closely associated with it through a larger, hierarchical cosmic structure. Our galaxy resides in a small collection of galaxies situated on the outskirts of a much greater concentration. The enormous gravitational influence of the distant Virgo Cluster still defines the movement of our local galactic neighborhood. Understanding the Milky Way’s true cosmic address requires examining the structures of galaxy groups, clusters, and superclusters.
Where the Milky Way Calls Home
The Milky Way is a member of the Local Group, a small gravitationally bound collection of galaxies that acts as our immediate cosmic neighborhood. This group is dominated by two large spiral galaxies: the Milky Way and the Andromeda Galaxy (M31). These two massive galaxies are separated by about 2.5 million light-years and are currently moving toward each other.
The Local Group contains over 50 galaxies, with the third largest being the Triangulum Galaxy (M33). The majority of the other members are smaller, less luminous dwarf galaxies that orbit the two main spirals. These include the Large and Small Magellanic Clouds, which are satellites of the Milky Way. The entire Local Group spans approximately 10 million light-years across and has a gravitational center located between the Milky Way and Andromeda.
Defining the Virgo Cluster
The Virgo Cluster represents the nearest massive concentration of galaxies to the Local Group. It is a true galaxy cluster, significantly larger and more populated than our galactic group. Its center is located approximately 54 million light-years away in the direction of the constellation Virgo.
This cluster contains between 1,300 and 2,000 member galaxies, far exceeding the population of the Local Group. The Virgo Cluster is not a uniform ball of galaxies but is composed of at least three major sub-clumps, suggesting it is still forming. Its enormous mass, estimated to be around 1.2 times 10 to the 15th power times the mass of the Sun, gives it a powerful gravitational pull. Within its core, the cluster is dominated by several giant elliptical galaxies, such as Messier 87 (M87), which contains a supermassive black hole.
The Larger Context: The Virgo Supercluster
While the Local Group is not inside the Virgo Cluster, both structures belong to a much larger entity known as the Virgo Supercluster, or the Local Supercluster. This supercluster is a massive, flattened disk-like structure that spans roughly 147 million light-years across. It contains over 100 groups and clusters of galaxies, including the Virgo Cluster, which acts as its immense gravitational center.
The Local Group is situated on the outskirts of this Supercluster, far from the dense central regions of the Virgo Cluster. Even at this distance, the Local Group is subject to the cluster’s immense gravity. The gravitational pull, often referred to as the “Virgocentric flow,” causes the Local Group to move toward the cluster at a velocity of hundreds of kilometers per second. This movement demonstrates a direct gravitational link between our small group and the massive cluster.
The Virgo Supercluster is a component of an even grander structure called the Laniakea Supercluster. Laniakea, a Hawaiian term meaning “immense heaven,” is a vast, interconnected web of galaxies spanning over 520 million light-years. The Laniakea Supercluster defines a gravitational basin where the motions of all member galaxies, including the Milky Way, are directed toward a common, distant gravitational center. The cosmic hierarchy places the Milky Way within the Local Group, which is part of the Virgo Supercluster, and that is a component of the Laniakea Supercluster.