The sun, Earth, and moon are in constant motion. The movements of these three giant spheres have an enormous influence on life here on Earth, so it’s a good idea to understand the ways in which our planet’s dance with its two most important neighbors shape our days, nights and seasons.
Watch this animation for a basic introduction. Then answer the questions in the Take Notes box below. Need help? You may pause the animation, rewatch it as many times as you like, and read the transcript.
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Transcript: Sky Dancing
Our solar system is so predictable.
The sun rises and sets, and the seasons change. The cause of these predictable earthly patterns? Movement– the movement of our planet, our moon, and their relative positions to each other and to the sun.
In the magnificent celestial dance of our solar system, there are the two main dance moves to consider: rotation and revolution.
Rotation is the movement of a celestial body spinning around its own axis.
And revolution is the orbital movement of one body around another.
The Earth rotates on a tilted axis as it revolves around the sun. The moon rotates on its axis as it revolves around the Earth– as Earth revolves around the sun.
This combination of rotation and revolution is the reason we have predictable patterns here on Earth. Patterns like:
Not bad for a two-step dance move!
In this lesson you’ll learn how the sun, the Earth, and the moon move. You’ll watch five short animations that explain how their relative positions impact changing seasons, captivating phases of the moon, awe-inspiring eclipses, and rhythmic patterns of tides. After taking notes and online quizzes, you’ll have a chance to organize what you’ve learned in an outline. Then you will create your own project to explain how the relative motion and relative position of the sun, Earth and moon affect these events.
1 Describe the difference between rotation and revolution.
2 List the patterns that are affected by the rotation and revolution of the Earth and moon.