The Holt & Miller Observatory houses our 10” Carl Zeiss Refracting Telescope, one of the largest historical artifacts in our collection (FI Cat.1437). During daytime hours, this fully functioning telescope provides the opportunity to safely view the Sun, including features such as sunspots and prominences, while the rooftop location offers a unique view of the Philadelphia Skyline.
The Holt & Miller Observatory is operated and maintained by the Franklin Institute’s Chief Astronomer, Derrick Pitts.
Did You Know:
When the Observatory first opened in 1934, it also featured a 24-inch Reflecting Telescope, which is now on display on the first floor of the museum.
Our telescope is only one of two surviving Zeiss Telescopes of this model. The other is located at the Griffith Observatory in Los Angeles.
The Holt & Miller Observatory is one of the few observatories in the country to provide optically safe, real-time, direct observation of solar activity.
Things to Do and See at the Holt & Miller Observatory
Observe the sun safely through our Zeiss Refractor Telescope and enjoy views of the Philadelphia Skyline.
Skyline & Scopes
View one of Philadelphia’s iconic skyline buildings through a reflecting telescope and learn about our historic observatory.
Visit the observatory and learn how telescopes work and what they can teach us about our Sun.