Hello everyone.

I'm so excited to be learning with you today.

I'm Mrs. Horan, and together we are going to be learning about the movement of the planets around the solar system.

Today's lesson is part of the Earth, sun, and moon unit.

This lesson is called, "The Movement of the Planets around the Sun." And we'll be learning to, "Describe the movement of the planets in the solar system in relation to the sun." We're going to find out about the planets and get moving to help us understand how they move.

Our lesson today builds on what you already know about the shape of objects in space and how the sun appears to move across the sky each day.

Today's learning is part of our big learning question, how does the Earth fit into the universe? These are the keywords that we're gonna be using today, solar system, sun, planets, and orbits.

Here are some explanations of the keywords.

I'll explain these words as we go through the lesson, so we don't need to read this now, this slide is just a helpful reminder that you might want to come back to later if you aren't sure about anything and you need a quick check.

And here is our lesson outline for today.

As you can see, the lesson is divided into two parts, let's get started with the first part of our lesson, our solar system.

Our solar system is made up of the sun and eight planets.

You can see them all there in the picture.

Can you spot our planet, Earth? It looks pretty small compared to some of the other ones.

You might already know something about some of the other planets.

We'll be taking a look at those later.

The word solar comes from the Latin word sol, which means sun.

You might have heard other words with this sol route, like solar power, which is energy that we get from the sun.

That might help you to remember that solar system means sun system.

In reality, the distances between the planets are very large.

The sun is so far away from Earth that if we wanted to fly there in a plane, it would take 19 years! Because the distances between planets and the sun are so very far, it's not possible to represent their size accurately to scale in a single picture.

If we wanted to do this, the picture would have to be incredibly big and the planets would still look very, very small, perhaps even too small to see.

This picture is an artistic image, to help us understand what the planets look like.

So this picture is not perfectly accurate, but it is still useful to help us understand what the planets look like.

You can see that they're all spherical, or ball shaped like this, but they're different colours and sizes.

The sun is a star at the centre of our solar system.

It's the same as all the other stars in the sky, but it looks different to us because it is much, much closer than the other stars.

Our sun is around 150 million kilometres away, which is pretty far, but our next closest star called Proximus Centura, is about nine and a half trillion kilometres away.

If we tried travelling to Proximus Centura using the fastest rocket we currently have on Earth, it would still take over 6,000 years to get there, so it's no wonder it looks so much smaller to us when it's so much further away.

The planets in our solar system travel around or orbit the sun.

That word orbit is one of our keywords today, and it means to travel around in a loop.

The sun does not move around the solar system.

Time for a quick check for understanding.

What is the name for the sun and the planets together? Is it A, sun system, B solar system or C planetary system? Well done! It's the solar system.

Remember that word sol means sun.

Next question, which of these is at the centre of the solar system? Is it A, Earth, B, moon or C sun? Great! It is the sun.

The sun stays in the centre of our solar system and does not move around it.

We're doing great so far.

Planet is one of our keywords for today.

Talk to a partner about what you think a planet is.

We all live on a planet so we all know something! Also, discuss how many planets you think there are in our solar system.

You might want to pause the video here if you've got a lot of ideas to share with your partner.

So a planet is a very large object in space made of rock or gas, which travels around or orbits a star.

Our sun is a star and the Earth is a rocky planet that orbits it.

There are eight planets in our solar system, including Earth.

They're all approximately spherical.

You probably remember that this means they're all shaped like spheres or balls.

The moon is not a planet because it orbits Earth, not the sun.

Remember, we can only call something a planet if it orbits the sun and since the moon orbits the Earth, we can can't call it a planet.

Do you know anything about the other planets? You might have heard about them on TV or read about them in books or maybe you've even heard some facts from friends or family.

Starting with the closest to the sun, the planets are called Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Apart from Earth, the planets are all named after ancient Greek and Roman gods and goddesses.

For example, Mars is named after the Greek and Roman God of war, because of its blood like red colouring.

You can see in this picture that the Earth is the third planet from the sun and there are some planets that are larger and some that are smaller than Earth.

Just like the one we looked at before, this picture is not to scale.

Do you know what this means? In reality, the planets are much further apart from each other than shown in this picture and their sizes are a little different.

This image is still useful though, because it helps us to understand what the planets look like and get an idea of which ones are bigger than others.

The planets all orbit the sun in an anti-clockwise direction.

This means to travel around the sun in the opposite direction to the hands of a clock.

You can see in the diagram there are some small arrows showing which way the planets orbit the sun.

Time for another check for understanding.

Think about this statement and decide whether you think it's true or false.

"The moon is a planet." It is false.

Now, can you justify your answer? Is it false because the moon is a large spherical object in space? Or is it false because the moon does not orbit a star? Fantastic! The moon is not a planet, because it does not orbit a star, it orbits our planet Earth.

Now it's time to get stuck in and start applying all your new knowledge.

The first part of task A is to complete these sentences.

A, is at the centre of our solar system.

B, there are planets travelling around the sun.

C, the path that each planet takes is called its.

And D, the direction the planets move around the sun is? Pause the video and have a go at filling in those gaps now.

Okay, let's see how you did.

The sun is at the centre of our solar system.

There are eight planets travelling around the sun.

The path that each planet takes is called its orbit.

And the direction the planets move around the sun is anti-clockwise.

Now we've got something a bit different for the second part of Task A.

Laura has drawn a diagram of the solar system, it's similar to the one we looked at before.

Can you spot any mistakes she has made? Pause the video, have a really good look and then come back when you think you've spotted all the mistakes.

Okay, let's see how you did.

You might have spotted that the arrow showing the orbits should point in an anti-clockwise direction and you might have noticed that there are only seven planets on Laura's diagram, there should be eight.

Now it's time for the second part of today's lesson, the orbits of the planets.

What do you think all eight planets have in common? It means, what is the same about them all? You can see in the picture there that there are definitely some differences between them.

They're different colours and sizes, one has rings and the others don't.

We also know that some are made of gas and some are made of rock, but what do they have in common? What similarities can you see? All eight planets are large spherical objects in space which orbit the sun, so they're all very big, they're all sphere shaped and they all travel around the sun.

We can see in this diagram, that the Earth orbits or travels around the sun in an anti-clockwise direction, just like the other planets.

How long do you think it might take Earth to orbit the sun? How long for the Earth to go all the way around and complete one full loop of the sun? Earth takes 365 and a quarter days to complete a full orbit of the sun, this is called a year.

What's really cool is you can work out how many times you have travelled around the sun based on your age.

So if you are nine years old, then you have travelled all the way around the sun nine times! Now, you might be wondering what we do about that quarter of a day each year.

Every four years, we add an extra day to the calendar to account for the quarter days in the last four orbits, this is called a leap year.

The extra day is always the 29th of February.

In leap years there are 366 days in a year.

You can tell if a year is a leap year because it will be a multiple of four, so 2024 is a leap year and so are 2028 and 2032.

Here's an interesting question.

Do you think all of the planet's orbits will be 365 and a quarter days long? Do you think they'll be longer? Or maybe you think they will be shorter? Hang on to your ideas, because we will be investigating them soon.

Okay, time to check in again on how our learning is going.

Our first question is, how long is a year? Is it A, 24 hours B, 24 days, C, 365 and a quarter hours or D, 365 and a quarter days? Great! A year is 365 and a quarter days long.

Second question, why is a year 365 and a quarter days long? Is it because A, that is how long it takes Earth to rotate on its axis.

Is it B, that is how long it takes Earth to orbit the sun or C, that is how long it takes the sun to orbit Earth.

Well done! A year is 365 and a quarter days long, because that is how long it takes the Earth to complete one full orbit of the sun.

Scientists use models to help describe and explain things that they cannot observe themselves, this might be because they're too big or too small to see or maybe it's just something we can't see with our own eyes.

Models can be 3D objects or they can be 2D diagrams. Often people use the word model to talk about something 3D, that you can touch and hold, but in science a model can also be a 2D picture.

This diagram of the solar system is a 2D model of the planets and their orbits.

You can see the sun in the centre and all of the planets orbiting around in an anti-clockwise direction.

The arrows have been added to the model to make it clearer.

In reality, you can't really see the path that the planets take and there are no arrows pointing in an anti-clockwise direction.

They've just been added to make the diagram clearer and easier to understand.

We are going to create our own 3D models to show how the planet's orbit the sun and make some observations.

This will help us find out whether all of the planets have an orbit that takes 365 and a quarter days, same as the Earth.

So here is your task, you'll be creating a model of the planets orbiting the sun.

First, choose something to represent the sun.

Think about what the sun looks like and what might be good to represent that in our model.

Then choose a person to become a planet and orbit the sun.

It might be a good idea to mark out the orbit on the ground with something like chalks, so you can be sure you're travelling all the way around and making a complete loop.

Time how long it takes to travel all the way around the sun.

You could use a stopwatch for this.

Then try moving closer to or further away from the sun, completing another orbit at the same speed and recording the time it takes.

Again, it will be really useful to draw out the path of your orbit on the ground, to make it clearer.

Finally, when you have completed a few orbits from different distances, look at your results and think, what do you notice? What is different about each one? Pause the video now and have a go at making your models.

Welcome back! How did it go? Did you enjoy making your models? Did they help you to understand how the planets orbit the sun? These children completed the same activity and this is what they noticed, you might have found something similar.

Aisha noticed that it took longer to orbit the sun if she was further away from it.

Sam noticed that it took her fewer steps to get around the sun when she was closer to it.

Lucas noticed that different planets took different amounts of time to orbit the sun.

The further away a planet was from the sun, the longer the orbit took.

Were your results similar to theirs? Did you notice anything different? This model we have used is great, because it helps us to understand that the further away from the sun a planet is the longer it takes to complete an orbit.

This is because the planets that are further away have further to travel.

You might have noticed when you were drawing out and walking along your orbits, that the ones closer to the sun were much shorter than the ones that were further away.

Mercury, which is the closest planet to the sun, only takes 88 days to complete a full orbit, that's much shorter than a year on Earth.

For Neptune, the furthest planet from the sun, it takes 60,190 days to get all the way around the sun, that's the same as 165 Earth years! We've come to the end of our lesson.

Let's summarise our key learning from today.

The sun is the centre of our solar system.

Eight planets, including Earth orbit the sun in an anticlockwise direction.

Each planet takes a different amount of time to orbit the sun.

The further away from the sun a planet is, the longer it takes.

It takes Earth 365 days to orbit the sun.

This is called a year.

Thank you so much for joining me today, everyone.

I've really enjoyed learning about the solar system with you, and thank you for your hard work and critical thinking.

See you again next time!.