Earth: Rotation vs. Revolution

Lesson Plan - Get It!

Audio:

The earth is constantly moving in two very different ways.

The earth rotates, or spins, at one thousand miles per hour! The earth spins on its axis.

Think of the earth's axis as an imaginary pole that goes through the earth — like a wheel on a toy car. You can spin the wheel and make it go quickly, but it doesn't come off the vehicle.

That's how the earth works on its axis. The Earth's axis keeps it spinning in place at a constant speed and in one direction.

Even though the earth is moving fast, people cannot feel it because they are moving along with the earth. The earth spins counterclockwise (like a clock spinning backward) from the west to the east.

Try it out!

Stand up and ask someone to be the axis, placing a finger on your head and spinning you counterclockwise steadily. Currently, you are rotating, just like the earth!

There are twenty-four hours in a day. It takes the earth twenty-four hours to complete a full rotation. This rotation causes day and night.

As the earth rotates, one side of the world is closer to the sun, while the other is further away. When one side of the earth faces the sun, it is day in that location. The opposite side of the earth is in the dark because it is facing away from the sun.

Think about where you are on the earth. If you are in North America or South America and it is daytime, it is now nighttime for people who live on the opposite side of the earth.

The earth is constantly rotating (spinning). It spins even when revolving around the sun.

Revolving is like taking a slow walk in a big circle. The earth revolves around the sun. It takes the earth three hundred and sixty-five days, or one year, to make one trip, or revolution, around the sun.

• Do you want to try acting like the earth revolving around the sun while rotating?

Find a big open area to avoid falling and getting hurt. Find a small object to put in the center of your area to represent the sun.

Stand a few steps from the sun and have someone help you rotate again by acting as your axis. Once you have a good rotation, slowly start walking around the sun in big, wide circles

• Can you rotate and revolve at the same time?

Try it again with a ball. This time, you are the axis, keeping the ball (the earth) rotating in place while you walk (or revolve) like the earth around the sun.

• Was that a little easier?
• Did that help you understand how the earth moves?

To help you understand the concepts of day and night, ask your helper to place — or stand with — a flashlight in the center to serve as the sun's light.

Do this several times until you understand how day and night are affected by how the earth moves about the sun.

The earth's revolution causes the seasons to change. People see changes in plants, temperatures, and weather in many parts of the world.

The earth's movement around the sun affects how much sun an area of the earth gets. The amount of sun in a region affects the plants, temperatures, and weather.

• What changes do you notice throughout the year?
• Does the weather change?
• Does it get hotter or more relaxed?
• Do the trees change?

• Are you amazed learning about the earth's rotation and revolution?

Before moving on to the Got It? section, answer this question.

• How long does the earth take to rotate around the sun?