The Vatican Observatory is one of the oldest astronomical research institutions in the world. It has its headquarters at the papal summer residence in Castel Gandolfo, Italy, outside Rome. Its dependent research center, the Vatican Observatory Research Group, is hosted by Steward Observatory at the University of Arizona, Tucson, USA.

The Vatican Observatory Research Group operates the 1.8m Alice P. Lennon Telescope with its Thomas J. Bannan Astrophysics Facility, known together as the Vatican Advanced Technology Telescope (VATT). This is located at the Mount Graham International Observatory (MGIO) in southeastern Arizona.

What you find in this website will help you discover the reason for the existence of the Vatican Observatory, its history, and its many activities. It will also invite you to participate, through the Vatican Observatory Foundation, in our work for science and for the Catholic Church.

We wish you a pleasant browsing experience, and we encourage you to contact us over any questions that this visit to our website provokes in you. We also welcome your suggestions on how to improve our website.