Jean Heidmann. French astronomer born in 1923. Engineer Central School, was hired in 1946 by Louis Leprince-Ringuet in the physics laboratory of the Ecole Polytechnique, for a program of research on cosmic rays, he obtained a doctorate in particle physics. Aware of the opportunities we have for the budding astronomy, he joined the Paris-Meudon Observatory. He was responsible for the discovery of a new family of objects, galaxies forming lumps. In the early 1980s he participated fully in the search for extraterrestrial life, actively collaborating in the SETI (Search for Extraterrestrial Intelligence). He is the author or coauthor of numerous books on the subject, including Cosmic Odyssey.