Astronomers using data from NASA’s Chandra X-ray Observatory and other telescopes have put together a detailed map of a rare collision between four galaxy clusters. Eventually all four clusters - each with a mass of at least several hundred trillion times that of the Sun -- will merge to form one of the most massive objects in the universe. Source: [url=http://www.nasa.gov/mission_pages/chandra/chandra-spots-a-mega-cluster-of-galaxies-in-the-making.html]Chandra Spots a Mega-Cluster of Galaxies in the Making[/url]