Musket Ball Cluster
The Musket Ball Cluster is a galaxy cluster that exhibits separation between its baryonic matter and dark matter components. The cluster is a recent merger of two galaxy clusters. It is named after the Bullet Cluster, as it is a slower collision, and older than the Bullet Cluster. This cluster is further along the process of merger than the Bullet Cluster, being some 500 million years older, at 700 million years old. The cluster was discovered in 2011 by the Deep Lens Survey. As of 2012, it is one of the few galaxy clusters to show a separation between its dark matter and baryonic matter components.