High on the Chajnantor plateau in the Chilean Andes, the European Southern Observatory (ESO), together with its international partners, is operating the Atacama Large Millimeter/submillimeter Array (ALMA) — a state-of-the-art telescope to study light from some of the coldest objects in the Universe. This light has wavelengths of around a millimetre, between infrared light and radio waves, and is therefore known as millimetre and submillimetre radiation. ALMA comprises 66 high-precision antennas, spread over distances of up to 16 kilometres, and is the largest ground-based astronomical project in existence. This panorama shows ALMA antennas underneath the arching Milky Way.. . ALMA plays a key role in the Event Horizon Telescope, a planet-scale array of eight ground-based telescopes designed to capture images of a black hole..