Cosmic heavyweights in free-for-all

		IMAGE: A labeled version of the MACSJ0717 image shows the galaxies in the four different clusters -- identified by the letters "A, " "B, " "C, " and "D " -- involved in the collision,... Click here for more information.

The most crowded collision of galaxy clusters has been identified by combining information from three different telescopes. This result gives scientists a chance to learn what happens when some of the largest objects in the Universe go at each other in a cosmic free-for-all.