Okay, so we’ve seen prettier space pics. But we love this one for two reasons. First, because this is the largest galaxy cluster discovered in the early universe, and that’s big news. But even better, the cluster has been named “El Gordo” by the researchers who discovered it. That translates to “the fat one,” which is by no means a misnomer.
Discovered by NASA’s Chandra X-ray Observatory and the National Science Foundation-funded Atacama Cosmology Telescope (ACT) in Chile (that’s where the Spanish name comes from), the cluster--officially ACT-CL J0102-4915 for those keeping score at home--resides some 7 billion light years from Earth. It’s the largest such galaxy cluster found at such a distance.
Galaxy clusters, of course, are the largest bodies held together by gravity in the entire universe. And because the formation of galaxy clusters relies not just on gravity, but on dark matter and dark energy, they are also good places to study the mysterious phenomena that make up most of the universe. That means El Gordo isn’t just a big boy, but a dark and mysterious one as well.