Slipher Building and Rotunda Museum

Constructed in 1916, the Slipher Building was created for the growing need of office and darkroom space. Serving as the main administrative building at Lowell Observatory, the Slipher Building was the last building constructed on campus before founder Percival Lowell's death in November 1916. A second story was added in 1923.

The Slipher Building is situated in the middle of campus and its facade includes the focal point of Lowell Observatory's campus, the Rotunda Museum. A large Saturn-shaped dome is the most recognizable marker of the Rotunda Museum that was originally used as a library. The interior still contains twin spiral staircases that lead to book shelves which hold the library of former astronomer Carl Lampland. The Rotunda Museum is now used for public programming.

The Slipher Building sits between the Clark Telescope and the Pluto Discovery Telescope, and it contains the apartment where Clyde Tombaugh was living when he discovered Pluto in 1930. The Slipher Building and Rotunda Museum are significant pieces of Lowell Observatory's history.