University of Tokyo Atacama Observatory

The University of Tokyo Atacama Observatory (TAO) is an astronomical observatory located on the summit of Cerro Chajnantor, at an altitude of within a lava dome in the Atacama Desert of northern Chile. The site is located less than north-northeast of the Llano de Chajnantor Observatory, where the Atacama Large Millimeter Array (ALMA) is located, but is over higher in elevation. It is also higher than the site proposed for the Fred Young Submillimeter Telescope on the same peak. The observatory is operated by the Graduate School of Science and Faculty of Science, University of Tokyo. Operation began in 2024.

The observatory operates the TAO 6.5m optical-infrared telescope at the site. The high altitude of the observatory is essential for its mission, as infrared light is absorbed by water vapor in the atmosphere, so it must be located at high altitude where the atmosphere is thin. In 2023, TAO was noted as one of the few major telescopes in the world with light pollution below acceptable levels of interference. Provided by Wikipedia