Giant Galaxy Cluster "El Gordo" Is Even Bigger Than We Thought

We already knew that this ancient galaxy cluster (nicknamed "El Gordo") was the largest of the distant galaxies that we had spotted, but it turns out we've been massively underestimating its size. How did astronomers figure it out? Simple. They weighed it. » 4/03/14 6:00pm 4/03/14 6:00pm