The Advanced Technology Solar Telescope (ATST) is a large domed solar telescope facility that is planned to be built by the National Solar Observatory atop the Haleakala volcano on the Pacific island of Maui, Hawaii, USA. The site was selected for its clear daytime atmospheric seeing conditions, which will enable study of the solar corona. The ATST enclosure will house a 4-meter diameter solar telescope capable of observing objects on the Sun that are 30 km across.
The ATST aims to resolve the fundamental interactions between solar magnetic fields and the dynamic atmospheric plasma on scales below 0.1 arcsec over entire active regions.
The ATST is a collaboration of 22 institutions, reflecting a broad segment of the solar physics community.