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Earth Is the Round Planet We Live On · Our Place in Space · Earth · planets

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Earth Is the Round Planet We Live On

with Nova

Nova the astronomy guide floats gently beside a glowing blue-and-green globe of Earth, pointing to swirls of white clouds and patches of land, while friendly animals and tiny people wave from the surface below.

Identify Earth as the planet where all living things live.
Describe Earth's shape as round like a ball.
Recognize that Earth has land, water, and air that living things need.
Compare Earth to other planets by naming one thing that makes Earth special.

Key terms

planet: A big, round ball of rock or gas that travels around the Sun.
Earth: Our round home planet, the only known place where living things live.
solar system: Our Sun together with all the planets and moons that travel around it.
Moon: Earth's rocky neighbor in space that travels around Earth and has no life.
atmosphere: The blanket of air around Earth that living things breathe and that holds clouds.

What Earth Is Made Of

Earth has three big parts that work together to keep us alive. There is land, made of soil, rock, mountains, and sand, where plants grow and animals walk. There is water, which fills the huge blue oceans and the lakes and rivers. And there is air, a layer all around Earth that we breathe and that holds the white clouds. Land, water, and air together make Earth a comfortable home.

Why Earth Looks Round From Space

When astronauts take pictures from space, Earth looks like a big blue marble. That is because Earth, like every planet, is shaped like a ball. Down on the ground the land looks flat because Earth is so enormous that we only see a tiny piece of it at a time. It is the same as a tiny ant on a basketball, which cannot feel the ball curving under its feet.

Worked examples

Explain what shape Earth really is.

Recall that all planets are shaped like balls.
Earth is a planet, so it must be ball-shaped too.
Picture the photo of Earth from space — a round blue marble.

Answer: Earth is round, shaped like a ball.

Decide whether a fish swimming belongs on Earth.

Ask: does a fish need water to live?
Yes, and Earth has oceans, lakes, and rivers full of water.
So a swimming fish belongs on Earth, where living things live.

Answer: Yes — a fish lives on Earth because Earth has the water it needs.

Hi, I am Nova! Today we are going to learn about a very special planet — Earth! Earth is a planet. A planet is a big, round ball that travels around the Sun. Earth is round, just like a ball you can hold in your hands. Look at Earth from space. Do you see the big blue areas that cover most of the surface? Those are water — oceans and lakes. Do you see the patches of green and brown in between, like islands of color? Those are land — mountains, forests, and deserts. Do you see the white swirly shapes curving across the top and sides? Those are clouds floating in the air. Earth is the one place in our solar system — that is the name for our Sun and all the planets that travel around it — where people, animals, and plants all live. Dogs, butterflies, oak trees, and you — everyone lives on Earth! Earth even has a neighbor called the Moon, which travels around Earth, but nothing lives on the Moon. Here is a little hint: when you look at a picture of Earth from space, it looks like a round, blue marble. That roundness is the shape of ALL planets, but Earth is the special one we call home.

Activity

Sort each picture into the right group: things found ON Earth or things that are NOT on Earth.

Practice

Name the three things Earth has that living things need to survive.

Tell one way Earth is different from the bare, dry Moon.

Common mistakes to avoid

Earth is flat like a pancake.Earth is round like a ball; it only looks flat because it is so very big.
People and animals could live on the Moon.The Moon has no air or liquid water, so living things cannot survive there.

Check your understanding

What shape is the planet Earth?

Where do people, animals, and plants all live?

A friend says Earth is flat because the ground looks flat when you walk on it. What would you tell your friend?

Recap

Earth is our round home planet, the only place in the solar system where people, animals, and plants live. It has land to stand on, water to drink and swim in, and air to breathe. Earth looks flat up close but is really shaped like a ball, just like every other planet.

Reflect

What do you love most about living on Earth, and why is it special to you?