The Museum features historical photographs taken at Mount Wilson Observatory and exhibits on current projects at the Observatory.
The Museum was built in 1936 and renovated in 1997 thanks to the generosity of Mr. Paul Gerstley, one of Mount Wilson's special friends. It displays the state of astronomical knowledge at that time with a second set of captions that explain advances in knowledge made over the last 60 years. A 256-seat auditorium, which is used for the Mount Wilson summer lecture series, is adjacent to the exhibit area.
For many years, the Museum was used for weekly public lectures followed by public viewing with the 60-inch telescope, then one of the largest telescopes in the world.