Every October, World Space Week invites people around the world to celebrate space exploration, innovation, and humanity’s enduring fascination with the Universe. This year, the occasion carries special meaning for the Cleveland Museum of Natural History. October 21, 2026, marks the 90th anniversary of the opening of the Museum’s Hanna Star Dome, an innovative achievement that brought the wonders of the night sky to Clevelanders and helped generations of visitors find their place among the stars.
View of the Hanna Star Dome, now located in the Messages in Light gallery.
A new way of exploring the stars
When the Hanna Star Dome opened in 1936, planetariums were still a new phenomenon in the United States. The Dome was one of the first in the country and the first in Ohio. Its creation fulfilled a dream more than 20 years in the making for then-Museum Director Harold L. Madison, who served first as the Museum’s Curator of Education and then as its Director from 1928 to 1939. Those who funded, planned, and constructed the project understood that astronomy could inspire people of every age to observe, ask questions, and see the natural world from a broader perspective.
A gift from Mrs. Paul Moore of Convent, New Jersey, made that dream possible. She funded the Dome in memory of her father, Leonard C. Hanna, whose family was closely connected to the Museum’s early history. In 1921, the Museum had acquired the Leonard C. Hanna House at 2717 Euclid Avenue. Located on the city’s famed Millionaires Row, the Hanna House served as the Museum’s home—and later, the Star Dome's home—until 1958. For many Clevelanders, it provided their first opportunity to explore the stars.
Exterior of the Hanna Star Dome, as pictured in 1938
Recreating Cleveland’s night sky
The Hanna Star Dome was a remarkable display of design and craftsmanship. Its solid-copper dome measured 16 feet across, weighed approximately one ton, and was assembled from 24 sections bolted together. The surface underneath was painted a deep blue-black to resemble the night sky, while the top was tinned to protect the copper from corrosion.
Creating the stars was an equally impressive undertaking. After the Dome was installed, Dorothy A. Treat and Harold L. Madison Jr. spent more than two months carefully positioning 48 constellations visible from Cleveland throughout the year. Each constellation required a separate setting for every month in which it could be seen at this latitude. The Big Dipper, visible in the northern sky throughout the year, had to be positioned 12 times. Scorpius, which appears low in the southern sky, required only five settings.
Altogether, 2,844 six-volt radio lamps transformed the copper ceiling into a glittering sky. Twelve different star fields—one for each month—could be selected using a rotary switch. During Museum hours, visitors could see the stars as they would appear over Cleveland between 9 and 11 pm on the day of their visit. Long before digital projections and immersive theaters, the Dome gave Clevelanders the extraordinary experience of watching the seasons unfold overhead.
Dorothy Treat, who contributed extensively as a Museum educator and staff member over the years, also authored an issue of the Museum’s Pocket Natural History series which the Museum released to coincide the Star Dome’s opening. In addition to describing the Dome’s features and construction, this guide provided detailed information about constellations, astronomy, and directions on using the star maps it contained to locate stars and constellations within the Dome.
Students gaze up at the Hanna Star Dome in a photo featured in Harold L. Madison Jr.’s 1938 article.
Capturing Northeast Ohio’s imagination
Following the installation of the Dome, Cleveland took notice. The day after a preview of the Dome, an October 22, 1936, a headline in The Plain Dealer announced, “Hanna Star Dome Shines in Premiere for Museum Crowd.” The accompanying story described a ceiling “set with 2,844 brilliants representing stars” that would help visitors recognize the gods, heroes, and animals imagined in the constellations by ancient observers.
Yet the Dome offered more than a lesson in identifying patterns in the sky. It connected visitors across time. Beneath its stars, people could look up just as humans had for thousands of years—wondering about the lights above them, telling stories about their shapes, and seeking to understand the Universe. “Children and grown-ups visiting our new sky take a keen interest in making friends with the stars and their curiosity leads them from one constellation to another,” Madison Jr. wrote in a 1938 article published in The Sky.
“The public’s acceptance of the Star Dome has been most gratifying,” he wrote later in the same article. “Since its completion over 175 groups of children and adults have requested and received lectures on stars given by museum staff members.”
Visitors gaze up at the dome in the Museum's current Nathan and Fannye Shafran Planetarium.
Advancing astronomy education and innovation
The Hanna Star Dome launched a tradition of indoor astronomy education at the Museum that has continued to evolve. On October 26, 1952, the Museum opened Cleveland’s first modern planetarium in a converted carriage barn at its Euclid Avenue location. Its Spitz projector could recreate the stars while also demonstrating the movements of the planets, Sun, and Moon. Meanwhile, the original Hanna Star Dome continued to reflect changing technology. In 1995, its thousands of lights were rewired using fiber optics, preserving its historic character while giving new life to its stars.
In 2002, the Museum opened the Nathan and Fannye Shafran Planetarium. Its angled roof points toward Polaris, the North Star, while fiber-optic lights embedded in its stainless-steel exterior evoke a constellation. More recently, during the Museum’s transformation, the planetarium was upgraded with enhanced sound, vivid visuals, and Digistar 7 software capable of presenting the cosmos in breathtaking detail.
The technology has changed dramatically since those first radio lamps flickered to life in 1936, but the inspiration behind it has not. We still look up with the same questions: What lies beyond our world? How did the Universe begin? Are we alone? What might we discover next?
As we celebrate the Hanna Star Dome’s 90th anniversary, we honor the educators, donors, scientists, and dreamers who made the Dome possible. Most of all, we celebrate the curiosity it continues to represent. For 90 years, its stars have reminded us that exploration begins with a simple act of looking up.
Curious to learn more? You can still visit the Hanna Star Dome in the Museum’s Messages in Light Gallery. Stop by for some old-fashioned stargazing before heading over to the Nathan and Fannye Shafran Planetarium for a live, interactive show led by Museum astronomers. Explore our current planetarium shows.
