Lowell Observatory comparing these measurements with a reference set of Sun-like stars. Lowell Observatory is building a major new reflecting telescope in partnership with Discovery Communications, located near Happy Jack, Arizona. This Discovery Channel Telescope (DCT), located within the Mogollon Rim Ranger District of the Coconino National Forest, is expected to be the fifth-largest telescope in the contiguous United States, and it will enable the astronomers of Lowell Observatory to enter new research areas deeper into outer space. The DCT and the research carried out there will be the focus of ongoing informative and educational television programs about astronomy, the sciences, and
Lowell Observatory Flagstaff. Also located on the Mars Hill campus is the Pluto Discovery Telescope, used by Clyde Tombaugh in 1930 to discover the dwarf planet Pluto. Lowell Observatory currently operates four research telescopes at its Anderson Mesa dark-sky site, located southeast of Flagstaff, including the Perkins Telescope (in partnership with Boston University) and the John S. Hall Telescope. Lowell is a partner with the United States Naval Observatory and Naval Research Laboratory in the Navy Precision Optical Interferometer (NPOI) also located at that site. The Observatory also operates smaller research telescopes at its historic site on Mars Hill and in Australia