1. Assignment 3: Sun, Earth, and moon

2. 1. Label Assignment 3: Sun, Earth and Moon in your Table of Contents, and on the next available page after Assignment 2.
2. Get a small diagram of the Sun, Earth and Moon from the table and glue it into your notebook on Assignment 3.
3. Pick a partner and use what you know about the Sun, Earth and Moon to label the model. Use as many details as you can.
4. Under your model, explain what causes the seasons on Earth.
5. Read.

3. Why do scientist use models?
How do scientists use models?

4. Scientists use models that show proportional relationships between objects to explain a natural phenomenon.
Some phenomena such as the movement of the universe or the Sun-Earth-Moon system are too large to observe so models must be used.

5. What causes the seasons on Earth
What causes the seasons on Earth? (You should have already given your answer or best guess under the model you glued into your notebook.)

6. The relative positions of the Sun, the Earth, and the Moon cause the day/night cycle, length of year, seasons, tides, eclipses, and moon phases.

7. Earth’s orbit is an ellipse
Earth’s orbit is an ellipse. Its closest point to the Sun is in January, and its farthest point is in July. Distance from the Sun does not cause the seasons. During the winter (in the northern hemisphere) the northern axis is tilted away from the Sun and during the summer the northern axis is tilted toward the Sun.

8. Earth’s tilt and its yearly revolution around the Sun causes seasonal changes in the height of the apparent path of the Sun, season weather, and in the appearance of the constellations.

10. What motion, rotation or revolution, causes day and night
What motion, rotation or revolution, causes day and night? How long is the process?

11. Rotation causes day and night. The process is 24 hours.

12. What is the difference between rotation and revolution
What is the difference between rotation and revolution? Give examples of each type.

13. Rotation is an object spinning on its axis
Rotation is an object spinning on its axis. Revolution is an object revolving around another.
Example: Earth rotates on its axis while also revolving around the Sun.

14. What causes the day/night cycle?

15. The rotation of Earth on its axis causes the day/night cycle.