Why is the Sky Blue? English Language Learning

50-minute English Lesson

In this English language learning lesson, we ask a question and learn the answer. It’s all about air and broken light

Learn English: read the story

Why is the sky blue?

Why is the sky blue? That question can be answered with some basic science that helps us understand air and light.

If you look up into the air on a clear day, you might think there’s nothing up there. But that would be wrong. Air contains a great number of things. It’s mostly gas, but there are other things like small pieces of dirt, water drops, and ice. All of these things together are called the atmosphere.

When light comes to earth from the sun, it moves through the atmosphere. When this light hits atmospheric gas, something special occurs. The blue light in the sun’s white light is separated from the other six colors.

Remember, white light contains seven colors which the human eye can see: red, orange, yellow, green, blue, indigo, and violet.

The size of blue light is really small compared to the other colors. Because of its tiny size, it can go inside a piece of gas. For a short moment, that piece of blue light hits the inside part of the gas and then exits. But now it’s moving in a different direction.

Now think about all the gas in the atmosphere. It’s changing the direction of a lot of blue light which is moving left, right and all around.

Eventually, it reaches earth. That’s the blue we observe when we look at the sky.

So, why is the sky blue? Actually, it’s not blue at all.

When we see blue, we’re not looking at the sky. Instead, we are looking at blue light which has collided with billions of bits of gas and traveled down to the earth’s surface.

Listen without reading

Learn English: Gap Fill

Listen to the story again and fill in the blanks.

Why is the sky blue? That question can be answered with some basic ________ that helps us understand air and ________ .

If you look up into the air on a clear day, you might think there’s ________ up there. But that would be wrong. Air contains a great number of things. It’s mostly ________ , but there are other things like small pieces of ________ , water ________ , and ________ . All of these things together are called the atmosphere.

When light comes to earth from the sun, it moves through the atmosphere. When this light hits atmospheric gas, something special ________ . The blue light in the sun’s white light is ________ from the other six colors.

Remember, white light contains seven colors which the ________ eye can see: red, orange, yellow, green, blue, indigo, and violet.

The size of blue light is really small compared to the other colors. Because of its ________ size, it can go ________ a piece of gas. For a short moment, that piece of blue light hits the inside part of the gas and then ________ . But now it’s moving in a different direction.

Now think about all the gas in the atmosphere. It’s changing the direction of a lot of blue light which is ________ left, right and all around.

Eventually, it ________ earth. That’s the blue we observe when we look at the sky.

So, why is the sky blue? ________ , it’s not blue at all.

When we see blue, we’re not looking at the sky. Instead, we are looking at blue light which has ________ with billions of bits of gas and traveled down to the earth’s surface.

ESL discussion questions

Talk about the story.

1. What kind of story is this?
2. What are some things in the atmosphere?
3. What happens when sunlight comes to the atmosphere?
4. How does blue light separate from white light?
5. Why is the sky blue?
6. Does this ESL listening story have a message? What is it?

Synonym match

Match the word or phrase on the left with the correct synonym.

Anagrams

MOVE THE LETTERS. MAKE A WORD FROM THE ENGLISH lesson.

1. CSROCU
2. CECNISE
3. TRID
4. RUASCFE
5. ODINIG
6. ROSVEBE

Writing practice

Write the five sentences. Put the words in the correct order.

1. we / blue / the / we / sky / when / look / at / the / that’s / observe
2. sky / we’re / looking / at / when / not / see / the / blue / we
3. up / might / on / the / into / you / look / if / nothing / you / a / day / there’s / think / air / clear / up / there
4. gas / now / all / the / the / think / atmosphere / / about / in
5. these / of / called / atmosphere / together / things / are / all / the

Another ESL listening story

Ready for another English language learning lesson? Try this free online listening comprehension lesson about the history of uber.

Watch a video and take notes

Did you like this English language learning story? Learn more English by watching this video about the blue sky.

1. Watch the video.
2. Take notes.
3. Make a list with at least eight facts.

Get the worksheet

Want to print out these ESL listening activities? Click to download the PDF worksheet.

Click to see the answers.