Founded in 1980 by Carl Sagan and two of his scientific colleagues, the Planetary Society advocates for all things space science, whether that be exploring planets, scanning the skies for near-earth objects (i.e., killer asteroids), looking for extraterrestrial intelligence, or developing “a revolutionary prototype pneumatic actuator-free regolith sample return system” – you know, to bring space rocks back from other planets. They also brought you the SETI@home project, the world’s largest distributed computing experiment, which means they were cloud computing before cloud computing was cool.
The Society was headquartered in one of the historic Vista del Arroyo bungalows, on what were formerly the northern grounds of the adjacent hotel. The bungalows, which were built between 1920 and 1938 from designs by prominent Pasadena architects, were basically abandoned in the 1980s after the government sold the properties to private owners who neglected the historic buildings. The bungalows were renovated and converted to homes by private developers in 2008.
The bungalow that the Planetary Society occupied was designed by in the 1920s by the Pasadena firm of Marston, Van Pelt & Maybury, whose local work also includes the Grace Nicholson Building (now the Pacific Asia Museum) and the Fenyes Estate, which is now home to the Pasadena Museum of History.
Update June 2019: The Planetary Society is now located at 60 S Los Robles Ave, in Pasadena, California.