El Gordo galaxy cluster. Composite image showing the El Gordo galaxy cluster in X-rays (blue) observed by NASA's Chandra X-ray Observatory (CXO), with optical data (red, green, and blue) observed by the European Southern Observatory's Very Large Telescope (VLT), and infrared emissions (red and orange) observed bythe NASA's Spitzer Space Telescope (SST). El Gordo consists of two galaxy clusters that are merging. El Gordo is over 7 billion light years distant, in the constellation of Phoenix. Image published in 2012.