Fred Lawrence Whipple Observatory, Amado, Arizona
The major instrument on Mt. Hopkins is the MMT Observatory's 6.5-m-diameter optical telescope (operated jointly by SAO and the University of Arizona). Others include a 10-m gamma-ray airshower Cerenkov telescope as well as the Peters Automated Infrared Imaging Telescope (PAIRITEL), a 1.3-m infrared telescope (formerly the northern 2MASS telescope, now operated by SAO); a 1.2-m imaging optical/infrared telescope; and the 1.5-m Tillinghast spectroscopic telescope. FLWO is also home to HAT, the Hungarian-made Automated Telescope.

Magellan Telescopes
The Las Campanas Observatory on Cerro Las Campanas in Chile, operates twin 6.5-m optical telescopes for a consortium of institutions, which includes Harvard University, the Carnegie Observatories, MIT, the University of Michigan, and the University of Arizona. Separated by 60 m, the twin telescopes afford fine "natural seeing," from an elevation of 2400 m (8000 feet) in the Chilean Andes and unparalleled access to the Southern Hemisphere skies for astronomers.

MMT Observatory
The MMT Observatory, a 6.5-meter-diameter optical telescope, is located on the summit of Mt. Hopkins at the Fred Lawrence Whipple Observatory, 30 miles south of Tucson, Arizona. The telescope (operated jointly by SAO and the University of Arizona) includes a suite of advanced wide-field imagers and spectrographs developed and deployed for the MMT by SAO scientists.