The Vatican Observatory will lend its telescope to Jesuit universities

Ximena Torres

Starting in the fall of 2026, students at Jesuit universities, such as ITESO, will have a new opportunity to explore the sky and the stars. This isn't about space travel, but rather access to the Vatican Advanced Technology Telescope (VATT), the astronomical research complex supported by the Catholic Church.

One of the most remarkable aspects of this news is that you don't even need to travel to Mount Graham, Arizona, where the observatory is located, to make it a reality. All you need is a research question and a computer with a couple of 4K monitors.

“What we can do now is operate the telescope remotely because in 2024 we updated the control system. Now it is possible to operate it basically by pressing a few buttons,” explained Pavel Gabor, SJ, deputy director of the Vatican Observatory, during his participation in the ITESO-Ibero Astronomy Week 2026.

The VATT's automated control system, named Don, was developed by ProjectSoft HK in the Czech Republic. It takes only about three minutes for its Programmable Logic Controller (PLC) to come online, allowing observation of the space from anywhere in the world.

The Vatican Observatory's intention in promoting the use of this instrument in higher education institutions is to encourage students to make scientific contributions from their time in the classroom. Gabor pointed out that the cycles for developing projects at universities are short, but sufficient to produce certain academic publications, such as those dealing with the tracking of asteroids and planets outside the Solar System.

Students at Fordham University in New York were the first to use the VATT remotely via the Don system, but Gabor explains that others are already interested. “There are other people from Georgetown University lining up to use the telescope, so I was wondering if, perhaps, there would be interest at ITESO in something similar,” the astronomer posed to the attendees of his talk.

How does a telescope work?

Gabor used his presentation to explain that telescopes have two essential functions that allow us to observe stars, nebulae, and other celestial bodies located billions of light-years from Earth. These are resolution and light-gathering capacity.

The first refers to the ability of an optical system to distinguish between two luminous objects that are close to each other, for example, two stars. This mechanism is a response to the phenomenon of diffraction, which refers to the distortion of waves—including light waves—when they pass through an obstacle or a body that acts as a slit. Pupil dilation is the human body's response to this type of event. Telescopes work in a similar way, but with much greater power; the VATT, for example, has 126 times the resolving power of the human eye.

On the other hand, light gathering, as the name suggests, refers to the number of photons a system can collect to produce an image. “If you take a short exposure of the Andromeda Galaxy, you’ll only see its center, but if you take a much longer exposure, you’ll be able to see other details,” explained Pavel Gabor, SJ.

In addition to resolution and light-gathering capacity, telescopes possess other mechanical characteristics that allow them to track celestial bodies despite their own movement and that of the Earth. Currently, most large telescopes, including the Vatican Telescope, are automated to accomplish this task using coordinates. They employ a tracking system that responds to the expected rotation of our planet, and an autoguiding system to correct for any deviations.

“The telescope we have at Mount Graham has an autoguiding system, but also a very precise tracking system. [...] If you need to make a six-hour exposure, you'll probably want to use autoguiding, but if it's a 20-minute exposure, tracking is sufficient,” he pointed out.
The VATT's observation instrument is a Gregorian telescope, which means it uses a pair of mirrors (one paraboloid and one ellipsoid) to reflect light and project an image onto the eyepiece. This system is complemented by cameras with sensors that convert the light into digital signals, which would otherwise be invisible to the human eye.

The Vatican Observatory

Gabor's presentation also led to an answer to a frequently asked question: why does the Pope have an astronomical observatory? Some have developed conspiracy theories claiming it's because the Vatican is planning its next mission to Mars, or because its observation site is a portal to another dimension. In reality, the best way to express the institution's mission was summarized by Pope John XXIII in the following sentence: "The observatory has a twofold mission: to explain science to the Church and to explain the Church to the world of science."

Initially, the Holy See's observation site was located outside Rome, at the Pope's summer residence in Castel Gandolfo. However, around 1960, light pollution prompted the search for a site with better conditions. This led them to Arizona in the 1980s. There, not all members are dedicated to astronomical observation; some conduct theoretical research.

The relationship between the Catholic Church and science began centuries ago, when Christopher Clavius developed the calendar we use today by order of Pope Gregory XIII in 1579. Clavius was a Jesuit, so his work inextricably linked the Society of Jesus and the Vatican in the latter's interest in making scientific contributions. Proof of this is that the Vatican Observatory has been directed by Jesuits since 1903. Now, that connection extends to Jesuit schools through the invitation to use the Vatican Astronomical Observatory (VATT) remotely.