The shape of the Earth, Sun and Moon
This Topic is About...
- I will learn about the shape of the Earth, Sun, and Moon.
- I will find out why the Earth, Sun, and Moon are the same shape.
- I will work out which types of scientific enquiry we need to use.
- I will research the Earth, Sun, and Moon.
- I will learn science by making a model.
You’re going to be a science explorer!
Key Words
- sphere
- spherical
Tap to Learn the Meanings!
- sphere: A perfectly round 3D shape, like a ball.
- spherical: Describing something that is shaped like a sphere.
Great work! You’re learning new geometry words.
The shape of the Earth, Sun and Moon
The Earth, the Sun and the Moon are all spheres. The same shape as a ball. We can say they are spherical.
Why are they all spheres?
Why are they not rough like rocks?
Could it be because of gravity?
FUN QUESTIONS
1. Can you name the five types of scientific enquiry?
Show answer
• Observing
• Testing / Investigating
• Classifying
• Researching / Using secondary sources
• Pattern seeking
2. Which of them can you use to find out more about the Earth, Sun and Moon?
Show answer
Think like a scientist
Researching the Earth, Sun and Moon
What can you find out about the Earth, Sun and Moon?
- Why are they spheres?
- Do they all have gravity?
- Are they the same size?
Write these and some of your own questions on a piece of paper.
Use books, videos or the internet to find out the answers to as many of the questions as you can.
How am I doing?
Have a look at a friend’s questions.
Can you help them with the answers?
Can they help you with yours?
Gravity makes spheres
The Earth, the Sun and the Moon are all spheres because of gravity.
Every object with mass has gravity. The more mass an object has the stronger the gravity.
The Moon is smaller than the Earth, so the Moon’s gravity is weaker than Earth’s.
The Sun is much bigger than the Earth, so the Sun’s gravity is much stronger than Earth’s.
An object’s gravity pulls everything towards the centre of the object.
The Earth is a sphere because the Earth’s gravity pulls everything, even itself, towards the centre.
The Moon is a sphere because the Moon’s gravity pulls all the rock it is made of towards the centre.
The Sun is a sphere because the Sun’s gravity pulls all the gas it is made of towards the centre.
Quick fact
Very small objects, like tiny asteroids, do not have strong enough gravity to pull themselves into a perfect sphere, so they can have very lumpy shapes.
Computer models
Scientists use models on computers to find out about many things like the human body, the weather and space.
This is a computer model showing how a rocket can use the Earth’s gravity to help it get to the Moon.
Computer models help scientists test ideas safely before trying them in real life.