NASA’s Chandra X-ray Observatory said that galaxy cluster MACS J0717 is one of the most complex and distorted galaxy clusters known. It’s the site of a collision between four four clusters, located about 5.4 billion light years away from Earth.
Galaxy clusters are enormous collections of hundreds or thousands of galaxies and vast reservoirs of hot gas embedded in massive clouds of dark matter. This images contains X-ray data from Chandra (blue), and optical light from Hubble (red, green, and blue).
The image is part of the “Frontier Fields” project, in which astronomers are studying half a dozen galaxy clusters, including MACS J0717.