The Astronomical Domes of the Pontifical Palace of Castel Gandolfo open to the public

Ninety years since their construction, the astronomical domes of the Pontifical Palace of Castel Gandolfo will be open to visitors for the first time ever. Visitors will be able to see the Vatican Observatory’s two perfectly functioning  domes: the “major dome”, which has a diameter of 8.5 meters, and is equipped with a Visual Telescope for the observation of stars and planets; and the “minor dome”, which has a diameter of 8 metres and a Double Astrograph, used for photographic surveys of the sky and of the position of the stars. A restricted number of visitors wil

l be able to access the dome on 19 October, thanks to a cooperation between the Pontifical Villas, the Specola Vaticana and the Vatican Museums.

The domes can be accessed via a spiral staircase that reaches the third floor of the Apostolic Palace, where the highest panoramic terrace is located, overlooking the beautiful view of the Lake below Castel Gandolfo. Pope Pius XI inaugurated the Vatican Observatory’s new location on 29 September 1935. The decision to move the Observatory from a building in the Vatican Gardens, which had been built at the request of Leo XIII, was due to increasing light pollution in Rome.

The astronomical observatory was rebuilt, fitted with three new telescopes and an astrophysics laboratory for spectral analysis, and entrusted to the Jesuits. One of the most important research programs it conducted during those years, was a study on variable stars.