In the 1980s, a group of astronomers noticed that galaxies are very unevenly distributed in space, with galactic superclusters separated by incredibly huge voids of visible ordinary matter.
The Great Attractor is huge and perplexing astrophysical enigma.
It is a gigantic concentration of matter spread over a wide area of about 400 million light-years. It is located approximately 250 million light-years away beyond the Hydra-Centaurus Supercluster at the center of the Laniakea Supercluster (home to the Milky Way and approximately 100,000 other nearby galaxies).
The Great Attractor is considered to be a gravitational anomaly that reveals the existence of a localized concentration of mass tens of thousands of times more massive than the Milky Way.
The anomaly is pulling hundreds of thousands of galaxies, including the Milky Way. This pulling happens at velocities of about 600 to thousands of kilometers (or miles) per second!
It lies in the so-called “Zone of Avoidance“, where the dust and stars of the Milky Way’s disk obscures as much as a quarter of the Earth’s visible sky.
The survey conducted in 2005 confirmed earlier theories that the Milky Way galaxy was in fact being pulled towards a much more massive cluster of galaxies near the Shapley Supercluster, which is beyond the Great Attractor.
The Shapley Supercluster (SCl 124) is the largest concentration of galaxies in our nearby universe. It contains more than 8000 galaxies with a total mass more than ten million billion times the mass of the Sun. It’s the most massive galaxy cluster within a billion light-years, and we and every galaxy in our region of the universe are moving toward it.