Description: Lowell Observatory is an astronomical observatory near Flagstaff, Arizona. It was founded in 1894 by astronomer Percival Lowell.
The observatory operates several telescopes at two locations in Flagstaff. The main facility, located on Mars Hill just west of downtown Flagstaff, houses the original 24-inch (.61-metre) Clark Refracting Telescope.
The telescope is listed as a US national historic landmark. Also located on the Mars Hill campus is the 0.33-metre Pluto Discovery Telescope, used by Clyde Tombaugh in 1930 to discover the planet Pluto.
The second observation site, atop Anderson Mesa, houses four telescopes, including a 1.8-metre Perkins telescope that it shares with Boston University, the 1.1-metre Hall Telescope and the Navy Prototype Optical Interferometer (NPOI).
The still to be built Discovery Channel Telescope will be located at a site known as Happy Jack.