A photo of the galaxy cluster ACT-CL J0102-4915 captured by the Hubble Space Telescope provides a small idea of ​​the vastness of this set of galaxies that has a total mass estimated at 3 million billion times the Sun’s. For this reason it’s been nicknamed “El Gordo”, which in Spanish means “the fat one”. It intensly emits X-rays and that’s another reason of interest for astronomers that led to observe it, discovering that it’s actually formed by two smaller – or less enormous – galaxy clusters that collided.