Timelapse of the Milky Way over the ALMA radio telescopes, in the Atacama Desert, Chile. The southern Milky Way, the Carina Nebula, and the Small Magellanic Cloud are seen. ALMA (Atacama Large Millimetre sub-millimetre Array) is an array of 66 radio telescopes located at an altitude of 5000 metres on the Chajnantor plateau. Data from the separate telescopes is combined by interferometry, making it one of the most powerful and complex observatories in the world.