Atacama Large Millimeter/submillimeter Array (ALMA), an international partnership of Europe, North America and East Asia in cooperation with the Republic of Chile, is the largest astronomical project in existence. It will be a single telescope of revolutionary design, composed initially of 66 high precision antennas located on the Chajnantor plateau, 5000 meters altitude in northern Chile.
ALMA is radically different from visible-light and infrared telescopes. It is an array of linked antennas acting as a single giant telescope, and it detects much longer wavelengths than those of visible light. Its images therefore look quite unlike more familiar pictures of the cosmos.
With millimeter and submillimeter waves (long wavelengths of light, much longer than the optical light we see with our eyes), star and planet formation can be watched, astrochemistry can be investigated, and the light that is reaching us from the Universe’s earliest galaxies can be detected.
This photo shows a 360-degree panorama of the Chajnantor plateau in the Atacama Desert, where ALMA is under construction. Credit: Serge Brunier / ESO.