This image from the Advanced Camera for Surveys on the NASA/ESA Hubble Space Telescope shows the central regions of the remarkable merging galaxy cluster Abell 2744. This object has been nicknamed Pandora’s Cluster because of the many different and strange phenomena that were unleashed by a huge collision that occurred over a period of 350 million years. A simultaneous pile-up between at least four separate clusters has produced strange effects that have never been seen together before.
NASA, ESA and D. Coe (STScI)/J. Merten (Heidelberg/Bologna)