The field of astrobiology, or the study of the origins of life on Earth and the signs of life in the Universe, is a vast one. Scientists from many disciplines converge to this field and bring their own expertise. The beauty of this science is in the numerous methods, techniques, and experiments carried out in order to answer one single, important question: how did we end up here, on this planet? The diversity of people, ideas and data encountered in this field is properly amazing! Through examples of historical and modern experiments, this webinar proposes to discuss the philosophy of astrobiology, its main hypotheses and more importantly the critical thinking associated with the scientific method. Also, there might be some cool pictures of distant worlds here and there.