Here we focus on those scientific concepts that are the hardest to explain to children. We break it down into what pupils need to know and outline the background science. Even though much of the background science does not need to be taught to primary aged children, it is useful for you as a teacher when addressing misconceptions and children’s challenging questions. 

Please refer to your national curriculum documents when planning your sequence of work and ensure that you teach the correct knowledge for your year group. 

What do children need to know about Earth and space? 

Learning about Earth and space should be science focused, provide opportunities for learners to develop key scientific skills and ask their own questions about our place in space. This topic doesn’t readily lend itself to hands-on learning but can be used as a context for science enquiry in other areas of the curriculum such as forces, light and materials. There should be significant focus on teacher explanation with models and developing explanations to support pupils learning in this topic. Children’s misconceptions are common in this topic because of the abstract nature of some of the scientific concepts, so it is important to be secure in your own understanding of the background science before you teach it. To give you further support addressing these misconceptions Explorify have created a teacher support document 'Children's misconceptions about space' in collaboration with The Best Evidence Science Teaching (BEST) team based at the University of York who have identified common misconceptions from educational research. This document highlights some of the more common misconceptions and mapped them to connected Explorify activities to help diagnose and rectify children's understanding.

We have included some ideas for how to teach Earth and space in part-two of this topic guide.

Key scientific concepts: Pupils need to know... 

1. Planet Earth orbits the Sun once a year.
2. Day and night occur because planet Earth spins on its axis.
3. The Moon orbits planet Earth.
4. The Earth, Sun and Moon are all spherical objects.
5. The Solar System consists of the Sun, orbited by the planets and other objects.

1. Planet Earth orbits the Sun once a year.

Pupils need to know:

• Our planet, Earth, goes around the Sun once a year.
• The Sun is a star that is much closer to us than all other stars.
• Over a year, parts of the Earth experience different seasons, each of which has different weather, temperatures and changes in nature.
• In the summer, the day length is longer than it is at other times of year.
• During the day, the position of the Sun in the sky changes – it is highest in the middle of the day.
• During the night, we can see other farther-away stars in patterns that we call constellations.
• Different constellations can be seen in different seasons.

Background Science for teachers

The Earth moves in two different ways, it orbits the sun and it spins on it’s axis. The Earth’s axis is an imaginary line going through the planet from pole to pole. The Earth spins around this line making one complete spin every 24 hours.

The Earth orbiting the Sun and spinning on its axis.

Image credit: The Ogden Trust. Licensed only for use on Explorify. 

The Earth’s axis is tilted. We have seasons because the Earth’s axis is tilted at an angle of 23º. In the summer, the northern hemisphere (half of the Earth) is tilted towards the Sun, this is when the days are longer and the Sun’s rays are more intense as the Sun is higher in the sky at all times of the day, giving us warmer temperatures. At this time, the southern hemisphere has shorter days and lower temperatures. In our winter, the northern hemisphere is tilted away from the Sun; the days are shorter, and the Sun’s rays are more spread out across the surface making it cooler. At this time, it is summer in the southern hemisphere.

Light rays from the Sun hitting the Earth.

Image credit: The Ogden Trust. Licensed only for use on Explorify. 

The night sky looks different over the seasons too. The Earth orbits the Sun over the year, which means in each season Earth is in a different position in its journey around the Sun. The night sky that we observe in each season is in the opposite direction to the Sun, this means that in each season we are looking out in a different direction into space so we see different constellations of stars.

A diagram of the different constellations of the zodiac, shown in their respective periods of the year- a result of Earth's rotation of the sun. 

Image credit: NASA/JPL-Caltech Licence here

2.    Day and night occur because planet Earth spins on its axis.

Pupils need to know:

• As well as our planet Earth orbiting around the Sun, it also spins on its own ‘axis’, an imaginary line going through its centre from north pole to south pole, every 24 hours.
• This rotation causes day (when where we are on Earth ‘faces’ the Sun) and night (when it doesn’t) and it also makes the Sun, Moon and stars appear to move across the sky.
• Objects standing in sunshine cast a shadow that points away from the Sun.
• At sunrise, when the Sun is low in the sky, the shadow of a vertical object is long.
• As the Earth rotates and the Sun moves across the sky from east to west, the shadow moves round too as it always points away from the Sun.
• The position of the shadow can be used to mark out the passing of time on a sundial.

Background Science for teachers

Planet Earth moves in two different ways. As well as our planet Earth orbiting the Sun, it also spins on its own axis. It is this movement that leads to parts of the planet having hours of daylight while other parts have hours of darkness (night). This BBC video is helpful.

A diagram demonstrating how Earth's movement on it's axis affects the light able to reach different areas of Earth at a given time- creating night and day.

Image credit: The Ogden Trust. Licensed only for use on Explorify.

It is daytime when rays of light from the Sun are falling on the part of the Earth where you are standing. The Earth rotates in an anticlockwise direction when viewed from above. This means that the Sun always appears to rise in the East and then set in the West.

A diagram illustrating the movement of the Sun between sunrise and sunset.

Image credit: The Ogden Trust. Licensed only for use on Explorify. 

There is also an apparent movement of the Moon and stars across the sky during the night-time. Long exposure photographs, such as the one shown below, show the stars appearing to move around the pole star. The pole star in the northern hemisphere (also called the North Star) is directly above the North pole of the Earth’s axis, so it doesn’t appear to move. This video explores the Sun and Moon’s apparent movement across the sky during the course of a day or night.

A long exposure photograph taken from space.

Image Credit: NASA – Long exposure photograph from ISS. Licence here.

3. The Moon orbits planet Earth.

Pupils need to know:

• The Moon is a rocky sphere, which is much smaller than the Earth and does not produce its own light.
• The Sun lights up the half of the Moon that is facing towards it and we see this part because its surface reflects the bright sunlight.
• Since the Moon orbits the Earth, taking approximately 28 days, its appearance changes on a regular cycle – we see different amounts of the side that the Sun lights up due to the Moon’s position relative to us and the Sun.

Background Science for teachers

When we see the Moon in the sky it looks about the same size as the Sun, however it is much, much smaller. It only looks a similar size because it is much, much closer to us than the Sun. The Moon’s diameter is a little more than one quarter of the Earth’s diameter. Like the planets, the Moon does not make its own light. The Sun lights up the half of the Moon that is facing towards it and we see the Moon because it reflects light from the Sun into our eyes. When we observe the Moon it appears to move across the sky once every 24 hours. (This observation is due to the Earth rotating on its axis.)

A diagram of the Moon orbiting the Earth, as light rays from the Sun point towards Earth. 

Image credit: The Ogden Trust. Licensed only for use on Explorify. 

Also, when we observe the Moon it appears to change shape slowly over a 28-day cycle

The appearance of the Moon from Earth depends on the Moon’s position relative to the Earth and the Sun. When it is on the opposite side of its orbit to the Sun, it appears as (or close to) a circular full moon, giving evidence that the Moon is a spherical shape. When it is on the same side of the Earth as the Sun, it reaches a position where we cannot see any of the side of the Moon lit by the Sun as this is now facing away from Earth. The apparent changing shape of the Moon is evidence that the Moon orbits the Earth once every 28 days. As the Moon orbits the Earth, we can see more or less of the half that reflects light from the Sun.

The phases of the Moon, illustrated as it orbits the Earth.

Image credit: The Ogden Trust. Licensed only for use on Explorify. 

4. The Earth, Moon and Sun are all spherical objects.

Pupils need to know:

• Although in everyday life the Earth’s surface appears flat, it is actually a giant sphere and one of eight planets in our solar system.
• The Moon is a smaller rocky sphere which orbits the Earth. Its diameter is about a quarter the size of the Earth’s and it is much closer to us than other natural objects in our solar system.
• The Sun is a giant sphere many times larger than the Earth, though it looks smaller since it is a huge distance away.
• The Sun is a star, which means it is very hot and it illuminates and warms the side of the Earth facing it.
• Other stars that we see at night appear as dots of light as most are millions of times further away than our Sun.

Background Science for teachers

The Sun is the star at the centre of our solar system which generates its own heat and light. It is a 4.5-billion-year-old hot glowing ball of hydrogen and helium, the centre of which reaches temperatures of 15 million °C. 

People have had ideas about the Earth being a sphere for thousands of years. Two thousand five hundred years ago, Greek philosopher Eratosthenes estimated the circumference of the Earth by using his measuring and geometry skills to compare shadows at two points on the Earth’s surface at midday on the summer solstice (the day of the year with the longest Sun hours).

Now, photographs and video footage taken from space provide direct evidence that planet Earth is shaped as a sphere, with a surface of oceans and land. The NASA photo below was taken from the camera on the Deep Space Climate Observatory satellite which is in orbit one million miles away from Earth. We also observe the Sun, Moon and other planets to be spherical objects.

A satelite photo of Earth.

Image Credit: NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring

As well as photographs from space travel, there is a huge body of evidence that shows the Earth is shaped as a sphere, including the facts that:

• travelling in one direction around the Earth brings a person back to where they started from.
• flying in a plane at a high altitude shows the horizon to be curved.
• the shadow of the Earth, as it moves across the Moon during a lunar eclipse, is observed to be a round shape.
• the bottom of a boat sailing far out to sea disappears from view before the top of the boat.

A drawing of a paper boat heading out to sea.

Image credit: The Ogden Trust. Licensed only for use on Explorify. 

Today we have the International Space Station and many other Earth observation satellites constantly orbiting our planet and sending images, video and data back to our planet that show the Earth is a sphere. There are also satellites orbiting the Moon, Sun and other planets and the images and videos they send back to Earth also clearly show that they are all spheres too.

The International Space Station and Earth.

Image credit: NASA Licence here.

5. The Solar System consists of the Sun, orbited by planets and other objects.

Pupils need to know:

• The Earth is one of eight planets orbiting the Sun, in order of increasing distance from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.
• Most of these planets have moons that orbit them.
• Pluto is a dwarf planet because it is much smaller than the 'other' planets.
• The Sun, planets and other orbiting objects are collectively known as the solar system.
• The Earth orbits the Sun once every year (365 and a quarter days), meaning it moves around the Sun in (roughly) a circle.

Background Science for teachers

The Sun, our nearest star, is at the centre of our solar system. Due to its large mass relative to the 8 Solar system planets it has a strong force of gravity that holds the eight planets, five dwarf planets and millions of asteroids, comets, and meteoroids, in orbits around it. The planets travel around the Sun in almost circular orbits on the same plane. The further away a planet is from the Sun the longer the path to orbit the Sun, consequently planets further from the Sun take a longer time to orbit it. As well as being different distances from the Sun, the eight planets have different day lengths, different temperatures, and different numbers of moons.

A diagram and table illustrating the distance between the Sun and the planets of the Solar System. 

Image credit: The Ogden Trust. Licensed only for use on Explorify. 

Astronomers originally thought that the Earth was at the centre of the solar system with the Sun, Moon and planets in orbit around it, this is called a geocentric model of the universe. As more evidence was gathered over time astronomers began to realise that the planets were in orbit around the Sun, a heliocentric universe (rather than a geocentric universe with the Earth at the centre).

A drawing of the Solar System.

Image credit: The Ogden Trust. Licensed only for use on Explorify. 

Useful related resources  

 Addressing children’s misconceptions about space

The Best Evidence Science Teaching (BEST) team based at the University of York have identified from educational research, the common misconceptions children have about space. In this teacher support document Explorify have highlighted some of the more common misconceptions and mapped them to connected Explorify activities to help diagnose and rectify these misconceptions.

Teacher support document- Children's misconceptions about space

Other useful resources

  The Ogden Trust:  Phizzi Focus: Earth and Space

  This Phizzi focus provides stimulating ideas and resources to link science to other primary curriculum areas.

  BEST: Earth and Space 

These resources highlight the key concepts that primary aged pupils need to understand and provides a toolkit to appropriately sequence lessons in this topic, along with diagnostic questions to reveal misunderstandings and response activities to challenge them.

Ideas to try with your class  

Now you've got the key scientific concepts under your belt, try our ideas to help you explore Earth and space with your class in a way they will understand in part two of this topic guide! 

You can also take a look at the related topic guides for light and forces. 

Many thanks to the Ogden Trust, who have collaborated with Explorify to produce this 'Tackle the tricky bits' page.

Image credit: Untitled by nohaggerty from Pixabay via Canva