The fourth edition of the Gerrei AstroFest will bring a full day of astronomy, hands-on workshops, and public stargazing to Sant'Andrea Frius, a small town in the Gerrei region of Sardinia, on Saturday, September 19, 2026. The event, organized by the Cagliari office of the National Institute for Astrophysics (INAF), is free and open to the public, with activities running from morning until late evening.
The day's program will unfold primarily in Piazzale Europa, where stands from INAF, the National Institute for Nuclear Physics (INFN), the Italian Space Agency (ASI), and CICAP will offer interactive laboratories and demonstrations. Starting at 10:00, the square will host the «Cody Maze astrofisico», an astronomical treasure hunt that uses coding rules and astronomy-themed challenges. Simultaneously, laboratory activities will begin at all stands.
At the INAF stand, children can build a cardboard model of the Sardinia Radio Telescope in the «Costruiamo SRT!» workshop. Another activity, «Disegniamo con il Sole», will use sunlight to create images of real objects. The ASI stand will focus on space exploration with «Space Mission: comunichiamo coi confini del Sistema Solare», where participants can experiment with interplanetary communications and build models of scientific instruments. The Einstein Telescope will be the centerpiece of the University of Cagliari's Physics Department space, in collaboration with INFN and INAF, offering experiments and demonstrations on gravity, gravitational waves, and the future European observatory that Sardinia is bidding to host in Lula (Nuoro).
Throughout the same hours, a station called «La nostra stella» will allow safe solar observation through a shielded optical telescope. At the municipal library, an exhibition titled «Il Sardinia Radio Telescope: un progetto di eccellenza per l'astrofisica in Sardegna» will be open from 10:30 to 12:30 and 17:00 to 18:00, featuring projects by Gerrei students from the «Il cielo in classe» initiative.
The afternoon will offer additional attractions. From 17:30 to 19:00, INAF Cagliari's interference-hunting van, equipped with a telescopic antenna used to detect radio interference that can disrupt Sardinia Radio Telescope observations, will be in the square. This offers a chance to learn why «radio silence» is crucial for astronomical research. At 18:00 in the municipal library, CICAP Sardinia will present the conference «La Luna e Urano nel Leone: l'astrologia sotto la lente della scienza», examining myths, horoscopes, and astrological beliefs through the scientific method. The talk is part of CICAP's «Stregati dalla Luna 2026» initiatives. The association will also host a gazebo in the square for playful, interactive discussions on debunking and scientific hoaxes.
At 19:30, Piazzale Europa will host «Body Astronomy – Il circo incontra l'universo», a show by Pietro Olla for CircoScienze – Associazione culturale «Le Strade di Macondo». Through juggling, balancing, and rotating bodies, the audience will discover physics principles that govern the universe in a spectacular and interactive way.
The evening will deepen the astronomical experience. At 21:00, a «Guida al cielo notturno» will provide a brief introduction to navigating the stars and recognizing what can be seen with the naked eye. From 21:30 to 22:30, «Sant'Andrea sotto le stelle» will offer guided stargazing with INAF researchers, revealing the wonders of the sky above Gerrei. The session is also part of NASA's International Observe the Moon Night celebrations.
Silvia Casu, a researcher and head of INAF Cagliari's education and outreach team, serves as scientific and artistic director. «No big names, no major concerts, no books to promote,» she said. «Just a lot of substance guaranteed by our partnerships and fun assured for those who, from all over Sardinia and perhaps beyond, decide to spend a truly different day in direct contact with the world of research. Territories that, like Gerrei, host major scientific infrastructures need moments when researchers meet people to talk about what they are most passionate about—in our case, all the incredible science concerning the sky above us. Only in this way can trust and true collaboration be established.»
Local logistics will be handled by a committee of representatives from the Municipality and Pro Loco of Sant'Andrea Frius and the Comitato Classe 1988, which will also manage the refreshment point during lunch and dinner hours. The event is organized by INAF Cagliari with support from Gal Sole Grano Terra.