McMath–Pierce Solar Telescope

The McMath-Pierce Solar Telescope is a solar observation tool at Kitt Peak that uses a large mirror system to study the sun. The instrument includes a heliostat that captures sunlight and routes it underground through a concrete tunnel to reach the main mirror chamber.

The telescope was completed in 1962 and held the title of world's largest solar instrument until 2019. When the Daniel K. Inouye Solar Telescope began operations, it took over the leading role in solar research.

The building was designed by American architect Myron Goldsmith and engineer Fazlur Rahman Khan, who merged scientific requirements with innovative design. Visitors can see how the architecture works together with the telescope's function to create an unusual structure.

The site sits at a mountain elevation and is open to visitors on certain days. Plan your visit for clear weather when you can see the facility and surrounding landscape clearly.

Sunlight travels through a diagonal shaft that extends roughly 110 feet (33 meters) vertically before turning to run about 200 feet (61 meters) horizontally underground. This design lets the instrument study solar rays in a stable way while protected from temperature changes on the surface.

Location: Arizona

Elevation above the sea: 2,096 m

Diameter: 203 cm

Part of: Kitt Peak National Observatory

Website: https://noirlab.edu/public/programs/kitt-peak-national-observatory/mcmath-pierce-solar-telescope

GPS coordinates: 31.95840,-111.59500

Latest update: December 10, 2025 15:48