Activity overview

Run the activity

1. Plan an investigation around a Big Question. What do the pupils already know about the shadows we see at sunrise and sunset?

• What causes the darkness of night?
• Where do our shadows go on cloudy days?
• What causes our shadows to change length over the course of a day?

2. How will the group explore the question? Prompt pupils to explain their ideas, qualify them and refine them based on views expressed by other people. What is their plan for the investigation?

3. Ask the class to imagine they had to present their investigation at a school assembly or to their family, how would they show their action plan?

Background science

In this image, taken from the International Space Station, you can see the Sun start to rise on Earth.

From Earth, we experience a sunrise the moment the top of the Sun first appears above the horizon following the darkness of night-time. Although the Sun appears to move across the sky, it is the Earth’s rotation that creates this illusion of motion, spinning one full rotation every 24 hours. We experience one sunrise and one sunset a day on Earth.

In the morning, the Sun appears to rise and moves upwards in the sky and then, during the afternoon, it descends again. As a result, shadows are longer at the beginning and end of the day, when the Sun is lowest in the sky, and shorter in the middle of the day when the Sun is at its highest. If observed carefully, the Sun also appears to move from east to west across the sky. This means that the direction of the shadows change as well as their length.  

In the summer, compared to winter, the Sun is seen earlier in the day, appears to rise to a higher point in the sky, and disappears beneath the horizon later in the day. 

The International Space Station (ISS), is a habitable satellite research laboratory situated in low Earth orbit. Travelling at an incredible 17,100 miles per hour, the ISS takes 90 minutes to complete one orbit of planet Earth. As a result, the astronauts onboard get to witness sunrise 16 times each day!

In addition to 16 sunrises, they also get to see 16 sunsets, which occur when the orbit of the ISS takes it out of direct view of the Sun. This absence of light plunges the ISS into the darkness of the Earth’s shadow, but not before it has had the chance to harness the power of light with its many solar panels and generate the electricity needed to keep it operational.

From space we can see that the Earth is a sphere. What other evidence do we have that the Earth is spherical? 

• 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 out to sea disappears from view before the top of the boat. 

Watch out for  

Some children will suggest that the Earth is flat because it appears flat them. This is because the world is so enormous compared to our tiny bodies. Some might think the Earth is round and flat, like a plate, or that it's a sphere inside which everyone lives Some even believe that there is one flat Earth that we live on and another spherical one in space. 

For a detailed guide to children’s misconceptions and a guide to questions to assess their prior knowledge look at these BEST resources.   

Take it further

Activities 

Head outdoors to experience the wonders of using shadows to tell the time with this Human Sundial lesson from the Royal Observatory, Greenwich. 

This BBC Terrific Scientific resource (activity 3) helps children explore how shadow position can be used to tell the time and tackles the common misconception about the Sun moving across the Earth. 

Linked Explorify activities - our recommendations:   

Find out more about extra-terrestrial shadows in this Odd One Out activity It’s a shady business. Discover how the appearance of other celestial bodies is affected by light and shadow in this Zoom In, Zoom Out activity Reflections on Mars, or consider Sun safety in space with this Big Question How can astronauts protect themselves from the sun when visiting Mars? 

Watch 

Watch this photo time-lapse of an orbital sunrise from the ISS.