This cross-curricular unit about the geology of Earth contains background information, a detailed glossary, Earth facts, and 20 hands-on activities for the classroom, including a culminating project.
- understand that Earth is a planet in constant motion
- work co-operatively in groups
- Globe of Earth
- Stickers to put on the globe
- Candle and matches or a small table lamp
- Paper for notetaking
- Optional: Drawing paper, one sheet per student
- Optional: Markers, colored pencils, or crayons
- Optional: Large map of the world (will be putting stickers on it)
Where in the World Are We?
Step 1: As a class, examine a globe of Earth. Ask students to observe the way the globe spins on its axis. Explain how the real Earth also rotates on its axis, and that the plane of its orbit is inclined at an angle of 23.5 degrees.
Step 2: Place a sticker where your town or state is located on the globe.
Optional: If you have time, complete the Find the Antipodes extension activity, allowing each student to find their antipode pair on the class globe.
Earth Orbits the Sun
Step 1: Clear an area in the middle of the classroom. Students can arrange their chairs in a circle looking at the cleared space.
Step 2: Place a lit candle or small table lamp (plugged in and turned on) in the middle of the floor to represent the Sun.
Step 3: Ask a student volunteer to hold the globe. Explain to students that the candle/lamp sun and the globe Earth are not in correct proportion, and that, in reality, the Sun is more than 100 times the size of Earth.
Step 4: Have the student carry the globe and walk around the candle/lamp sun.
Step 5: Have the student carrying the globe turn the globe on its access while continuing to walk around the candle/lamp sun. Explain that not only does Earth move around the Sun, but that the Earth rotates on its axis at the same time.
Step 6: Encourage students to observe the classroom sticker on the globe and how it changes position relative to the Sun. Explain which movements create day and night in the United States as Earth rotates on its axis, and the changing seasons as Earth completes one orbit of the Sun.
Optional: Break students into small groups of three and spread them throughout the classroom. Have one student in each group stand in place as the Sun, and another student turn in slow circles around the Sun. The third student should observe for now.
The Moon Moves, Too
Step 1: Have the class come back to the candle/lamp sun. Choose another student volunteer to be the globe carrier. This time, ask for a second student volunteer.
Step 2: While the student with the globe walks around the candle/lamp sun, turning the globe, have the second student volunteer be the moon! The second student should walk around Earth as it rotates and orbits the Sun. Have the student volunteers walk slowly so the other students can clearly see the demonstration.
Step 3: Explain that the moon takes the same time to complete one orbit of Earth as it does to complete one rotation on its axis. One side is therefore turned permanently to Earth. The moon reflects light from the Sun.
Step 4: Encourage students to draw conclusions about the phases of the moon, from new moon (dark), to crescent moon (first quarter half-moon), to gibbous, to full moon, and all the way back again to new moon.
Optional: Have students draw the phases of the moon, illustrating how much of the moon is visible at each phase.
Tide In, Tide Out
Step 1: Explain to students that the rise and fall of the ocean twice a day is called a tide. Ask them to think about how high the water is on the beach at one time of the day and then how low it is at another time of the day.
Step 2: Tides are caused by the force of the moon's gravity pulling on Earth. Encourage students to draw conclusions about the progression of the tides around Earth as it rotates. The average time between high tides is 12 hours and 25 minutes.
Antipodes are places opposite each other on the globe. For example, the South Pole is opposite the North Pole, and China is opposite Chile.
Step 1: Have students find the antipodes of their home. Here is a formula for determining the antipode of any given location:
- Find the latitude of your home and change its direction. For example, if the latitude is south, make it north.
- Find the longitude of your home and subtract it from 180, then change its direction. For example, if the longitude is east, make it west.
- You now have the latitude and longitude of the opposite point on the globe.
Step 2: After students have determined the antipode for their hometown, have each student choose a point on the globe to start digging.
Step 3: Ask the students to calculate where they would end up if they could dig right through Earth.
Optional: Use stickers and students' initials to mark each pair of antipodes on a large map of the world.
Adapted from "The Earth," Senior Topics. Published by Ashton Scholastic in Australia.