What are we learning?
Introduction to Earth's Structure and the Solar System
The Earth is made of four main layers, each with different properties. The crust is the thin outer layer where we live. Below that is the mantle, a thick layer of very hot rock. Deeper still is the outer core, made of liquid metal, and at the very center is the inner core, made of solid metal. Our planet Earth is one of eight planets that orbit the Sun in our solar system. We will also learn about the three states of matter: solid, liquid, and gas.
Your lesson journey
First, watch the teacher model how to describe the structure of Earth and identify the properties of objects in the solar system (MS-ESS1-3). Next, practise it together as a class. Then, work independently: In the worksheet, you will label a diagram of Earth's layers, write the names of the eight planets in order from the Sun, and sort examples of matter into solid, liquid, or gas categories.
Scientists compare planets using the same features each time. Location, composition, size, moons and rings give us evidence for deciding whether a planet belongs to the inner or outer group.
1. Locate the planet
First, check its position. The four rocky inner planets are before the asteroid belt; the four giant outer planets are beyond it.
2. Compare key features
Use the same features for both planets: rocky or gaseous/icy composition, relative size, distance from the Sun, moons and rings.
Worked comparison: Mercury and Jupiter
Mercury is a small, rocky inner planet close to the Sun with no moons. Jupiter is a huge outer gas giant with many moons, faint rings and the Great Red Spot. These features explain why they belong to different groups.
Complete the worksheet independently. Label the four layers of the Earth on the diagram. Write the names of the eight planets in order from the Sun. Sort the examples of matter into the correct columns: solid, liquid, or gas.
✅ Success Reminder
Check that you have labeled all four Earth layers, written all eight planet names in the correct order, and placed each example in the right state of matter column.
💡 If you're stuck
If you need help, look back at the diagrams and examples we used. Remember the mnemonic 'My Very Educated Mother Just Served Us Nachos' for planet order.
🚀 Early Finisher Challenge
When you finish, choose one planet and write one interesting fact about it. Then explain why the inner core is solid even though it is the hottest layer.
