Sidereus Nuncius: aspectos (bio)éticos da aventura humana no espaço, entre a astrobiologia e a medicina aeroespacial

Abstract

Human expansion into the cosmos, driven by technological advances and the desire for knowledge, places humanity before challenges that go beyond mere technical mastery. This thesis – situated at the intersection of astrobiology, aerospace medicine, and bioethics – investigates the foundations and ethical implications of life beyond Earth. Developed using bibliographic review techniques – both narrative and integrative – and a theoretical essay, the research reveals a fundamental paradox: prebiotic chemistry suggests the potential universality of life, while human exposure to space reveals a radical vulnerability. Microgravity, cosmic radiation, and confinement trigger profound physiological adaptations – bone and muscle loss, immune and psychological changes, among others – which challenge the notion of straightforward colonization. In this scenario, the assessment of planetary habitability and the search for biosignatures become acts laden with responsibility. Critical analysis demonstrates that traditional ethical frameworks are insufficient to deal with the radical novelty of cosmic dilemmas. The results of this investigation were organized into six articles, which constitute the body of the thesis: (1) "Life in Space, Beyond Earth: Habitability in Question – Between Astrobiology and Aerospace Medicine"; (2) "Prebiotic Chemistry and the Origin of Living Beings: Current State, Scientific Perspectives, and (Bio)ethical Questions"; (3) "Physiological Adaptations to Life in Space: An Update"; (4) "The Origins of Life, Between Science and (Bio)ethics: Debates Surrounding Prebiotic Chemistry and the First Living Beings"; (5) "Planetary Habitability: Current State and Frontier (Bio)ethical Issues"; and (6) "Bioethics, Human Activity in Space, and Planetary Habitability: Frontier Issues and Theoretical Approaches." These challenges demand more comprehensive moral reflection. Thus, a synergistic integration of Protection Bioethics – anchored in the precautionary principle – and "(Bio)ethics for All Beings" – which extends moral consideration to all forms of existence – is proposed. This interdisciplinary framework argues that the space adventure should be guided not by a paradigm of conquest, but by one of coexistence and cosmic care. The central conclusion is that the success of the human journey into the cosmos will be measured not by the distance traveled, but by the ethical wisdom demonstrated in honoring and protecting the diversity of existence.