A special edition of Sciences et Avenir, published in July-August 2026, explores a range of speculative scenarios that examine how Earth and space might change in the future. This issue invites readers to consider both the challenges and possibilities that could arise from scientific, environmental, and societal shifts. The topics covered are diverse, ranging from the hypothetical survival of dinosaurs to the dramatic disappearance of the Moon and the occurrence of major solar storms that could disrupt technology on Earth. The issue also delves into environmental concerns, such as a world without pesticides, the collapse of soybean crops due to climate or disease, and the exhaustion of the world’s last oil reserves. These scenarios highlight the potential consequences of resource depletion and agricultural instability. Additionally, the edition considers more extreme possibilities, such as the disappearance of human civilization, the complete melting of all glaciers, and a significant rise in greenhouse gas emissions, which could lead to irreversible climate changes. Other topics include the revival of extinct species through advances in genetic engineering and the implications of major scientific breakthroughs. For instance, the issue explores a world where artificial intelligence solves all mathematical problems or where controlled nuclear fusion becomes a reliable energy source, potentially transforming global energy systems. These scenarios reflect on how such advancements might reshape industries, economies, and daily life. The edition also addresses medical and societal changes, such as the possibility of ceasing to have children due to ethical, environmental, or economic reasons, the eradication of all cancers through medical advances, and shifts in human life expectancy. These speculative scenarios offer a glimpse into the complex interplay between science, society, and the environment, encouraging readers to think critically about the future of humanity.