The Celestial Mechanics: the secrets of the ancient Zeiss Mark II Projector

On the date on which we remember the anniversary of the first moon landing that brought humanity closer to the sky (21 July 1969), the Rome Planetarium dedicates an evening to celebrating the instrument that, vice versa, brought the sky closer to humanity: the historic projector Zeiss Mark II, a masterpiece of optics and technology of the 1920s, which was the protagonist and creator of the wonderful starry nights in the first location of the Planetarium, the Octagonal Hall of the Baths of Diocletian, from 1928 until the 1980s.

The event, entitled “The Celestial Mechanics: the secrets of the ancient Zeiss Mark II Projector”, will take place on Sunday 21 July at 9.00 pm in the current location of the Planetarium at the Museum of Roman Civilization in EUR, in whose atrium there is the Zeiss Mark II projector was exhibited.

The initiative, promoted by Roma Capitale, Department of Culture, Capitoline Superintendence of Cultural Heritage, is part of the cycle of events with which the Planetarium of Rome, already last year, has joined and participates in the international celebrations for the Centenary of the Planetariums , which began at the end of 2023 and runs until May 2025, to commemorate the invention of the modern planetarium.

During the evening, you will be able to study the ancient instrument up close to understand all the mechanical and optical secrets that allowed it to create an extraordinary reproduction of the entire starry sky on the dome of the Octagonal Hall – the Mark II model was the first to project both celestial hemispheres – and its phenomena: the rotation of the celestial vault, the movements of the Sun, the Moon and the planets, widespread celestial bodies such as the Milky Way and the brightest galaxies, and even the colors of the stars and precession of the equinoxes.

Thanks to a detailed photographic service, created by astronomers Gianluca Masi and Gabriele Catanzaro, the “old Zeiss” will be virtually brought to life under the digital dome, highlighting aspects, at first sight incomprehensible, of the imposing structure of the projector, in order to understand the functionality and appreciate the ingenious technological solutions adopted by its builders.

You will also have the opportunity, thanks to the special participation of Ettore Perozzi, of the Italian Space Agency, to listen to the story of one of the last witnesses who had the opportunity to study the use of the ancient Zeiss projector to animate the sky in the Octagonal Hall, to remember how the machine worked and discover “how it managed” to evoke in visitors every time the wonder of what was baptized as the “Miracle of Jena”, from the name of the German town where the first modern planetarium was invented in 1923 .

Completing the evening will be a guided tour in which the Planetarium’s astronomers will lead the public in front of the large Mark II projector to explore its magnificent secrets up close.

To participate in the event, the purchase of an entrance ticket is mandatory. For info and details, consult the web page https://www.planetarioroma.it/it/informazioni_pratiche/biglietti or call the call center 060608 (open every day 9.00-19.00).