This assignment, prepared for the Foundations of Sustainability in Education course (ED1411) at James Cook University, investigates the Earth's water cycle and solar still technology. It begins with a detailed explanation of the hydrological cycle, including evaporation, condensation, transpiration, and precipitation, and their roles in water collection, purification, and distribution. The assignment then explores the functionality of solar stills, explaining how they utilize solar energy for water purification and discussing their advantages and disadvantages. Furthermore, it delves into the molecular-level changes during evaporation and condensation. The assignment also identifies key factors influencing the effectiveness of solar stills and concludes by evaluating solar stills as models of the Earth’s water cycle, providing a comprehensive understanding of water sustainability and related technologies.