Inside the McMath-Pierce Solar Telescope.

Sunlight reflecting off optical components Inside the McMath-Pierce Solar Telescope. The McMath-Pierce Solar Telescope was the largest solar telescope in the world upon its completion in 1962, a title it held until the first light of the National Solar Observatory’s Daniel K. Inouye Solar Telescope in December 2019. The interior of the McMath-Pierce Solar Telescope is currently being renovated to become the Windows on the Universe Center for Astronomy Outreach.