What contact with the night sky can we still have in towns and cities? How are we polluting the night with all our electric dazzle? If we consider the stars or the Milky Way as a natural heritage, how can we allow ourselves to erase them from our memory with our excess light?

Out in space, we witness huge illuminated areas covering the Earth. Urban growth has invaded natural reserves and disrupted nocturnal ecosystems, introducing light into the lives of species that depend on the darkness. Astronomical observatories no longer carry out scientific observations and are now reduced to museums.

Raul Cerveira Lima, from the Instituto de Astrofísica e Ciências do Espaço (IA) (Institute of Astrophysics and Space Sciences), Universidade de Coimbra e Politécnico do Porto, and Martin Pawley, of Ío, Agrupación Astronómica Coruñesa (Coruñesa Astronomical Group), critic and film programmer, are both experts in light pollution, and will talk about light, its excesses, and simple ways in which people, institutions, architecture, and urbanism can preserve the night and our contact with the Cosmos.