The Atacama Large Millimeter Array (ALMA)

The Atacama Large Millimeter Array (ALMA), one of the largest ground-based astronomy projects of the next decade, is a major new facility for world astronomy. ALMA is an international collaboration to develop a world-class telescope array to study the universe from a site in the foothills of Chile's Andes Mountains. Each of ALMA's antenna dishes will measure 12 m wide. The ALMA antennas will be movable. At its largest, the array will measure 14 km, and at its smallest, only 150 m. Its receivers will cover the range from 30 to 950 GHz. The ALMA correlator, a specialized computer that combines the information received by the antennas, will perform an astounding 16,000 million-million (1.6x1016) operations per second. An additional, compact array of 7-m and 12-m antennas is also foreseen. Construction of ALMA started in 2003 and will be completed in 2012; it will become incrementally operational from 2010 on.

ALMA is located on the high-altitude Llano de Chajnantor (5000 m elevation), east of the village of San Pedro de Atacama in Chile. The land has been given in concession to CONICYT (The Chilean National Commission for Science and Technology) by the "Ministerio de Bienes Nacionales" (Ministry of National Assets). It has also been declared a national reserve for science because of its unique capabilities for astronomical research. ALMA's location in the Atacama Desert is one of the highest, driest places on Earth, making it ideal for astronomical research at millimetre wavelengths, which are absorbed by atmospheric moisture. When completed (in 2011), ALMA will be the largest and most capable imaging array of telescopes in the world.