Earth's Tile and the Seasons

The Earth’s tilt and orbit around the Sun is modelled with a globe and lamp to investigate why seasons occur. By observing changes in day length, sun angle, and heating effects at different latitudes, students explore how axial tilt causes the seasons.

1. Darken the classroom and place a lamp without a shade at the center to represent the Sun.
2. Position a globe about 1 meter away from the lamp, with its axis tilted at 23.5° and fixed in direction.
3. Identify the North Star direction (to maintain correct tilt orientation throughout).
4. Slowly move the globe in a circle around the lamp to simulate Earth’s orbit.
5. At several orbital positions (solstices and equinoxes), observe which hemisphere tilts toward or away from the Sun.
6. Record observations about the angle of sunlight, intensity of illumination, and relative day/night lengths at different latitudes.
7. Compare results for northern and southern hemispheres.

How the Earth’s Tilt Causes Seasons | Day and Night Explained with Simple Science Models! - Ms Shelley's Science Show:

📄 Modeling the Seasons - Exploratorium: https://cleanet.org/resources/55938.html

📄 Seasons: Skydome - Institute of Physics: https://spark.iop.org/seasons-skydome

• Use a thermometer or light sensor to measure differences in light intensity at different tilt angles.
• Have each student use a smaller handheld globe to follow along with the orbit.
• Compare Earth with a hypothetical planet with no axial tilt.
• Extend to show how polar regions experience 24-hour daylight or night at solstices.

• Use a low-heat bulb or LED lamp to avoid burns.
• Ensure the lamp is stable to prevent tipping.
• Darkened rooms may increase trip hazards; arrange equipment with clear paths.

• Why do northern and southern hemispheres experience opposite seasons at the same time? (Because Earth’s tilt causes one hemisphere to lean toward the Sun while the other leans away.)
• Why are days longer in summer and shorter in winter? (The tilt changes how long the Sun stays above the horizon.)
• Why is summer warmer than winter? (Sunlight strikes the ground more directly and for a longer time each day.)
• What would happen if Earth had no tilt? (There would be no seasonal changes, only variation from equator to poles.)
• Why does this activity require pointing Earth’s axis toward the North Star? (To keep the tilt direction constant during the orbit, as it is in reality.)