McMath-Pierce Solar Telescope

The McMath-Pierce Solar Telescope is the largest solar instrument in the world. This is also the world's largest unobstructed aperture optical telescope, with a diameter of 1.6 meters. The structure includes a tower nearly 100 feet in height from which a shaft slants two hundred feet to the ground. The shaft continues into the mountain, forming an underground tunnel where the sun is viewed at the prime focus. An aerial shot of the top of the McMath-Pierce telescope reveals the 3-mirror heliostat which collects light and directs it down the tunnel. Unlike other solar telescopes, the McMath-Pierce is sensitive enough to observe bright stars in the night. Permanent instruments include a dual grating spectrograph capable of extended wavelength coverage (0.3-12 microns), a 1-meter Fourier Transform Spectrometer for both solar and laboratory analysis, and a high-dispersion stellar spectrometer. Important discoveries revealed with this telescope include: a detection of water and isotopic helium in the sun; solar emission lines at 12 microns; first measurement of Kilogauss magnetic fields outside sunspots and the very weak intra-network fields; first high resolution images at 1.6 and 10 microns; detection of a natural maser in the Martian atmosphere.