Earth is a planet in our solar system. The Sun is the solar system’s star. Our solar system is one small part of the Milky Way galaxy, which has billions of stars. The universe includes many galaxies and the space between them. A nested picture shows membership, not a stack of solid shells. Safety: Draw the size comparison on paper. Do not use tiny objects or cross a road to model distance. Stop: Stop at membership and the supplied comparison. No complete universe map or distance walk is required.

Materials: Paper; Pencil; Four folded paper labels 1. Draw four nested boxes. Label the smallest Earth, the next solar system, the next Milky Way galaxy, and the largest universe. Inside the solar-system box put a Sun dot and eight planet labels. In the galaxy box add several other star dots; write: a few symbols stand for billions of stars. 2. Write these relationship cards: Earth belongs to the solar system; the Sun is one star in the Milky Way; the Milky Way is one galaxy in the universe. Point from each card to the correct pair of boxes. 3. Use this supplied consistent comparison: a 24 cm Sun gives an Earth about 2.2 mm wide, about 26 m away. Draw a broken line labelled 26 m represented, not measured. Keep the distance label with the size comparison. 4. Cover the box labels. Retell planet → solar system → galaxy → universe. Explain why the Sun is not a galaxy and why our galaxy is not the whole universe. Write one sentence about what the 26 m comparison shows. Done: Finish four membership boxes, three relationship cards, and a scale-limit sentence. Proof: Keep the nested diagram and comparison. Note if the adult supplied any level name or ordering. Stop: Stop at membership and the supplied comparison. No complete universe map or distance walk is required.