Atacama Submillimeter Telescope Experiment, Radio telescope at Llano de Chajnantor Observatory, Chile

The Atacama Submillimeter Telescope Experiment is a 10-meter Cassegrain radio telescope on Pampa La Bola, near Cerro Chajnantor in northern Chile's Atacama Desert, at about 4,800 meters. Mitsubishi Electric built the antenna as a preprototype for ALMA; its aluminum panels carry a plastic coating, and the surface is held to roughly 20 micrometers. It sits about 10 km north of ALMA.

The telescope was built in Japan in 2000, transported to Chile and reassembled by 2002, and began regular observations in 2004. Since then it has contributed to studying the early universe and star formation.

The telescope represents joint scientific work between Japanese and Chilean researchers, who operate and share observations together at this high-altitude site.

The ASTE is not open to the public: it stands near 4,800 m on Pampa La Bola, close to Cerro Chajnantor, and the National Astronomical Observatory of Japan states that no public access is planned because of the altitude. Information on the telescope and its results is instead presented at the NAOJ Nobeyama and Mitaka open-house events.

The antenna surface is crafted with extreme precision to within 19 micrometers, allowing it to capture extremely faint radio signals from space. This level of accuracy is what makes it possible to detect very distant and weak cosmic sources.