Across the solar system, ice is scattered on comets, planets and moons. Where there is ice, there is water, raising the possibility of life elsewhere in the cosmos. To understand what we may discover out there, scientists journey to Earth’s frozen extremes: probing microbes living on air alone, uncovering ecosystems in glaciers, and measuring algae transforming the ice itself. From drones beneath Arctic seas to submersible dives under Antarctica, their work leaves us with a profound truth: life, in all its resilience and strangeness, is not confined to warm, sunlit places. Sometimes, it begins in the cold stillness of ice.