At US$1.3 billion, the Atacama Large Millimeter/Submillimeter Array (ALMA) is the world’s most expensive ground-based telescope. Situated on the 5,050-m-high Chajnantor plateau in the Chilean Andes, ALMA studies light from some of the universe’s coldest objects. It comprises 66 high-precision antennas, spread over distances up to 10 miles. Its main 12-m array has 50 antennas, each 12 m in diameter, acting together as a single telescope – an interferometer. ALMA’s complete set of 66 antennas can be configured to provide a powerful variable “zoom”. The surfaces of the radio dish arrays are near perfect, deviating from an exact parabola by no more than 20 micrometers (20 millionths of a meter). This prevents any incoming radio waves from being lost, so that the resulting picture captures as much distant cosmic light as possible. Each array weighs about 100 tons, and is made from ultra-stable CFRP (Carbon Fiber Reinforced Plastic) for the reflector base, with reflecting panels of rhodium-coated nickel. Considered also to be the most powerful and largest ground-based astronomical project in existence, ALMA will allow astronomers to study star and planet formation, molecular clouds and the very earliest moments of the universe.ALMA is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. It was inaugurated on 13 March 2013.