The eTwinning project on cosmic rays introduces students to the study of these fundamental particles, exploring their origin, characteristics, possible uses and scientific significance. Through a structured educational journey, students will delve into:What cosmic rays are and their purpose. Which particles compose them. The scientists who discovered them. A key feature of the project is the use of the MOCRIL and the Cosmic Hunter particle detector, allowing real-time measurements. As the teacher responsible for the project, I will personally handle the measurements in my laboratory, sharing the data with students and proposing exercises and laboratory activities. Students will not only acquire theoretical knowledge but also actively participate in data analysis, learning how to interpret astrophysical phenomena and use advanced scientific instruments. Studying cosmic rays is not only a way to explore the mysteries of the universe, but also a concrete opportunity to develop high-impact educational and scientific projects in the STEAM field, connecting schools, research and local communities. Through this research path, our school has participated in important national and international initiatives, obtaining significant results: the first prize in Beijing, the Atlante Award, the inclusion of our projects in the ESA ESERO platform and the selection of a drawing made by a student as the cover image of the official brochure of the International Cosmic Day.At the heart of the project is the MOCRIL detector, developed by Prof. Marco Schioppa (University of Calabria - INFN), a sophisticated instrument designed to study cosmic muons in extreme environments, from high mountain altitudes to scuba diving in lakes. In combination with the Cosmic Hunter, it enables continuous and detailed experimental monitoring. Studying cosmic particles also opens the door to interdisciplinary applications in fields such as medical physics, geophysics and environmental sciences. For example, understanding electrons and their properties has been fundamental to the development of photovoltaic cells, which convert sunlight into electrical energy. Similarly, research into the interactions between light and matter, which also involves photons (elementary particles of light), is the basis of numerous technologies, from lasers to fibre-optic communications.Today, particles are used in addition as a tool for investigation and therapy in medicine. In addition to PET (Positron Emission Tomography) and hadrontherapy (therapy with proton or ion beams), particles are also fundamental in:Conventional radiotherapy: beams of electrons and photons (X-rays and gamma rays) are used to destroy tumor cells. Diagnostic imaging: in addition to PET, which detects the annihilation of positrons emitted by radiopharmaceuticals, SPECT (Single Photon Emission Computed Tomography) also uses radioactive tracers that emit photons to obtain functional images of organs. Research and development of new drugs: radioactive isotope tracing techniques allow studying the path and metabolism of drugs within the body. Exploring cosmic rays means unlocking the secrets of the universe and inspiring future generations of scientists.Prof. Giuseppe Fiamingo – Founder of the project – IIS "P. Galluppi", Tropea – Italy - Prof.ssa Yeliz Terkan Mutlu - Co-founder member - Opet Anatolian High School (Turkey-Tekirdağ) - The project involved schools from Italy, Spain, Bulgaria, and Turkey : Emine İşçi – 19 Mayıs Ortaokulu - Sümeyye Aykaç – 19 Mayıs Ortaokulu - Hatice Büşra Orbuk – 19 Mayıs Ortaokulu - Turkey - Mahmut KARASU - Şehit Sıddık Uluocak İmam Hatip Ortaokulu -