About TMT

The Thirty Meter Telescope (TMT) is an optical-infrared, next-generation extremely large astronomy telescope with a 30-m aperture that is currently under construction. Construction of TMT is progressing through international cooperation between the National Institutes of Natural Sciences (in Japan), the University of California and California Institute of Technology (in the United States), the National Research Council (in Canada) and the Department of Science and Technology (in India). In the United States, preparations are underway for the National Science Foundation (NSF) to officially join through federal funding, and currently, the Association of Universities for Research in Astronomy (AURA) is participating as an associate member. Japan will be responsible for vital components, including the construction of the telescope structure, the light-gathering primary mirror, and science instruments. Once completed, the telescope will achieve an unprecedented level of resolution and sensitivity.

The defining feature of TMT is its extremely large primary mirror. As its name implies, the primary mirror is 30 meters in diameter. The primary mirror is composed of 492 smaller segments of hexagonal mirrors. In order to make the best use of the light-collecting power of the primary mirror, TMT will be equipped with state-of-the-art technology, including an adaptive optics system that compensates for atmospheric fluctuations in real time. Development is also underway for first light instruments to be put into operation upon completion of the telescope, including IRIS (InfraRed Imaging Spectrograph), WFOS (Wide Field Optical Spectrometer), and MODHIS (Multi-Objective Diffraction-limited High-Resolution Infrared Spectrograph).