In 1959, the United States Air Force’s Aeronautical Chart and Information Center (ACIC) began mapping the Moon in anticipation of lunar exploration. To enhance the map details, scientists realized they must make direct observations through telescopes.
To accomplish this, the ACIC used telescopes at Lowell Observatory and operated an office here from 1961 through 1969. Scientific illustrators, photographers, and visual observers worked together to make observations and then create the maps. They utilized both the 24-inch Clark Telescope, currently open for daytime tours and evening viewing, and a 20-inch instrument then housed in the white dome just north of where Lowell Observatory's Putnam Collection Center now stands.
By the end of the project, ACIC staff completed dozens of maps, which significantly advanced our knowledge of the lunar surface and helped enable the successful manned missions to the Moon.