The Atacama Desert at dusk. The Cerro Armazones Observatory appears like a future human base on Mars, an oasis in the desert. Operated jointly by the Ruhr University Bochum (RUB) in Germany and the Catholic University of the North (UCN) in Chile, the Cerro Armazones Observatory is isolated from any outsource power and is fully operated by solar and wind energy, an entirely "Green" observatory. it is located on the slopes of Cerro Armazones, a mountain in the Atacama Desert, Antofagasta Region of Chile, which will host the European Extremely Large Telescope (E-ELT), an optical/infrared telescope with a 39.3 metre diameter primary mirror, the largest on Earth. It should be operational in the early 2020s.