MDAS was founded in 1957 by a group of amateur astronomers who participated in the Smithsonian Astrophysical Observatory's Moon-Watch program, which enlisted amateur astronomers to observe artificial satellites. Earlier that year, the Soviet Union had launched the world's first orbital satellite, Sputnik 1, and MDAS tracked satellites from its post atop Mount Diablo and members' back yards.
The return of Halley's Comet in 1985 sparked widespread interest in stargazing, so MDAS joined with California State Parks to sponsor a series of comet viewings. They were so successful that the park and MDAS entered into an agreement to continue the public star parties. Now, 20 years later, Volunteers in Parks docents and park officials host monthly stargazing parties from March through October.