The Coma Cluster of Galaxies
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Courtesy of NASA.

Large-Scale Structure: Your Place in the Universe

We have seen that stars cluster together to form galaxies. Galaxies also cluster together to form much larger structures. There are clusters of galaxies called Groups which contain 10's of galaxies. Our own galaxy, the Milky Way resides in such a group of about 30 galaxies, named the Local Group.

Additionally there are much larger clusters of galaxies containing anywhere from 50 - 1000's of galaxies. The closest cluster to us is the Virgo cluster. The average distance between clusters is some tens of millions of Light-years.

Groups and Clusters cluster together to form even larger clusters known as Superclusters. The Local Group belongs to the Local Supercluster, whose center is at the Virgo Cluster. In between Superclusters are enormous voids of space where there are almost no galaxies at all.

The Largest structures discovered in the Universe are systems of voids and clusters. At this scale the Universe takes on a foamy look. The voids appear as great bubbles and galaxies lie along them in great filaments that connect Superclusters.

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