The 19th International Masterclasses on particle, astroparticle and medical physics, the international initiative sponsored by IPPOG (International Particle Physics Outreach Group), got underway on 10 February, taking thousands of students from around the world on a journey of discovery into the infinitely small. This year more than 2,800 high school students from all over Italy will participate in the Masterclasses, coordinated in Italy by INFN in collaboration with universities. They will take place until 6 April with more than 60 events at universities in 26 Italian cities. The students, who will participate at the same time as their peers from other countries, will have the opportunity to experience a day in the life of a scientific collaboration of a large particle physics experiment, directly analysing data from some of the main detectors at CERN's LHC super accelerator in Geneva, and the KEK laboratory in Tsukuba, Japan. But they will also explore the secrets of astroparticles with data from the Pierre Auger Observatory in the Argentine Pampas, and discover how physics research can help medicine with the masterclass in Particle Therapy, organised in collaboration with the CNAO, National Center for Oncology Hadrontherapy. The Masterclasses take place simultaneously in 60 different countries, involving more than 200 of the most prestigious research institutions and universities worldwide and more than 13,000 high school students. For INFN this year the Divisions of Bari, Bologna, Cagliari, Catania, Cosenza, Ferrara, Florence, Genoa, L'Aquila, Lecce, Milano Bicocca, Milan, Naples, Padua, Parma, Pavia, Perugia, Pisa, Rome, Roma Tor Vergata, Roma Tre, Salerno, Turin, Trieste, Trento and Udine, and the Frascati National Laboratories (LNF) and the Gran Sasso National Laboratories (LNGS) will be present.
