This strand provides an ideal setting for developing generalising principles and crosscutting concepts. To develop a sense of the structure of the universe and some organising principles of astronomy, students explore relationships between many kinds of astronomical objects and evidence for the history of the universe. Students use data to discern patterns in the motion of the Sun, Moon, and stars and develop models to explain and predict phenomena such as day and night, seasons, and lunar phases. The cycling of matter, with carbon and water cycles as well-known examples, provides a rich setting for students to develop an understanding of many physical and chemical processes including energy conservation and energy resources, weather and climate, and the idea of cycling itself. They will come to appreciate the impact of human activity on Earth and explore the role and implications of human space exploration.