Sun Position Changes

Look up at the bright sky during the day. You will see the sun. The sun seems to travel across the sky. It rises in the morning. It sets in the evening. Does the sun really move? Let us find out!

You learned about white light before. You learned about the visible spectrum. You know about rainbow colors. Now we must look at the sun itself. The sun is the source of our light.

Earth Is Spinning

The sun does not actually travel across our sky. Earth is the moving object. Our planet spins like a toy top.

In plain words: Earth spins around. This spin creates an illusion. The sun appears to travel across the sky.

You stand on the spinning Earth. You look up at the sky. You see the sun in different spots. The sun stays still in space. We just turn to face it. We turn away from it at night.

This spin takes one whole day. It takes twenty-four hours to spin once. Think about riding on a merry-go-round. You spin in a circle. Your friends stand still on the grass. Your friends appear to move. They are not moving. You are the moving one. Earth works the exact same way.

High Noon and Shadows

Where is the sun in the middle of the day? It sits very high in the sky. We call this time high noon 2. You can look at shadows to find high noon. A short shadow indicates a high sun 2.

Stand outside at noon. Look down at your shadow. Your shadow is very short. The sun shines almost straight down. The light travels a short path to reach you.

The sun reaches its highest point. It feels very warm at this time. The sunlight is very direct.

You can test this with a flashlight. Hold a flashlight right above a toy. The toy makes a tiny shadow. The light hits the toy directly. The sun does this to you at noon.

Moving Toward Evening

After noon, the sun looks lower. It slowly drops down the sky. Evening arrives. The sun sits near the ground.

Look at your shadow in the evening. Your shadow grows very long. The sun shines from the side.

Hold your flashlight to the side of your toy. The toy makes a very long shadow. The light hits the toy from an angle. The evening sun does this to you.

The sky might start to change colors. The sun gets closer to the horizon. The horizon is the edge of the visible land.

The sun's light must travel farther to reach you now. It moves through more invisible air. You will learn about this longer path next time. The air molecules scatter the light waves.

A Year of Sun Paths

The sun does not take the exact same path every day. Its path changes over the whole year 3.

In plain words: The noon sun changes its spot. It is not in the exact same place every day.

It moves a little bit each day. Over one whole year, it draws a special shape in the sky. The shape looks like a number eight. Scientists call this shape an analemma 4.

You can track the sun's path. You can mark its setting spot each night. The spot will move along the horizon. It moves a tiny bit every single day. The seasons change during the year. The sun sits higher in the summer. The sun sits lower in the winter.

Let us review the sun's daily changes.

• Morning: The sun sits low.
• Noon: The sun sits very high.
• Evening: The sun sits low again.

Earth spins. This spin causes these changes. The spin gives us day and night. The spin changes the sun's apparent spot. We see the sun move from east to west. The sun is our steady star. Earth is our spinning home.

Key Terms

• apparent motion 1 — The way an object looks like it is moving when it is actually still.
• high noon 2 — The time of day when the sun reaches its highest point in the sky.
• analemma 4 — A figure-eight shape that shows the sun's changing position in the sky over a whole year.