A system of colliding galaxy clusters, nicknamed the Musket Ball Cluster, has been discovered. In these images of the Musket Ball Cluster, the hot gas observed with Chandra is colored red, and the galaxies in the optical image from Hubble appear as mostly white and yellow. The location of the majority of the matter in the cluster (dominated by dark matter) is colored blue. The matter distribution is determined by using data from Subaru, Hubble, and the Mayall Telescope that reveal the effects of gravitational lensing, an effect predicted by Albert Einstein where large masses can distort the light from distant objects.
X-ray: NASA/CXC/UCDavis/W.Dawson, et al.; Optical: NASA/STScI/UCDavis/W.Dawson, et al.