Hubble cashes in Abell’s richest cluster

The universe contains some truly massive objects. Although we are still unsure how such gigantic things come to be, the current leading theory is known as hierarchical clustering, whereby small clumps of matter collide and merge to grow ever larger. The 14-billion-year history of the universe has seen the formation of some enormous cosmic structures, including galaxy groups, clusters, and superclusters—the largest known structures in the cosmos!