Presentation of the exhibition. Participants: Marco Bersanelli, Professor of Astrophysics at the Università degli Studi, Milan; Valter Maggi, Professor of Physical Geography and Climatology at the Università degli Studi, Milan-Bicocca; Carlo Sozzi, CNR Researcher. Introduced by Elio Sindoni, Director of the Department of Sciences of the Environment and the Territory at the Università degli Studi, Milan Bicocca.