The galaxy cluster Abell 2744 contains so many unusual phenomena that astronomers have dubbed it "Pandora's Cluster," after the mythological box said to contain all the world's ills. A galaxy cluster is a large scale structure that contains hundreds to thousands of gravitationally bound galaxies. When galaxy clusters collide they can release energies equivalent to 10,000 supernovae per year for one billion years. By studying these collisions, astronomers can study the behavior of dark matter by its interaction with normal matter.