NUCLIO - Núcleo Interactivo de Astronomia - is a non-profit organization that brings together researchers and teachers from the fields of science and education, with the aim of promoting innovation in education.

NUCLIO coordinates the Galileo Teacher Training Program (GTTP), one of the largest in the world involving over 100 countries.

NUCLIO coordinates and participates as a partner in several national and international projects, such as: Astronomers Without Borders, Dark Sky Rangers, European School Innovation Academy, Open Schools for Open Societies, Global Science Opera, Our Space Our Future, Islands Diversity for Science Education, Digital Schools, Frontiers, Go-Lab, GO-GA (Go-Lab Goes Africa), IASC (International Astronomical Search Collaboration), PLATON, PLOAD (Portuguese Language Office of Astronomy for Development), Stories of Tomorrow and Science on Stage.

Since its establishment, the organisation has reached directly over 3,000 teachers at a national level and over 50 000 teachers at a global level. NUCLIO also promotes scientific outreach actions, such as night sky observations and talks with scientists.