Work through each section in order. Read carefully, think first, then apply what you've learnt.
You already know that the Earth spins on its axis — an imaginary line through the North and South Poles — giving us day and night. But there's something crucial about that axis: it is tilted.
The Earth's axis is tilted at 23.5°. And here's the key thing — it always tilts in the same direction, towards the Pole Star. It doesn't tilt towards or away from the Sun. Instead, as the Earth orbits the Sun over the course of a year, the tilt means that sometimes the northern hemisphere leans towards the Sun, and sometimes it leans away.
The angle of Earth's axial tilt
The axis always points this direction
One complete orbit of the Sun
It's not just about how long the Sun is up — it's also about the angle of the Sun's rays when they hit Earth.
In summer, the Sun is higher in the sky. Its rays hit the UK at a steep angle, concentrating energy over a small area — like shining a torch straight down at the floor. In winter, the Sun is low in the sky. The same rays arrive at a shallow angle and spread over a much larger area, so the energy is diluted. The same amount of sunshine, spread over more ground, means less warmth per square metre.
This is why summer is warmer — not because the Earth is closer to the Sun (it's actually slightly further away in summer!) but because the rays hit us more directly.
The diagram shows the Earth at four points in its orbit. Use the label bank to label the diagram correctly. Select a label, then click on the diagram to place it. You can drag labels to move them.
Label bank — click a label to select it, then click on the diagram:
Once all labels are placed, take a screenshot to submit to Google Classroom.
The effects of Earth's tilt aren't the same everywhere. They become more extreme the further you move from the equator towards the poles.
At the equator, the tilt barely affects day length at all. The equator always receives roughly 12 hours of daylight all year round, because no matter which way Earth tilts, the equator stays in the middle and faces the Sun equally.
At the poles, the effect is dramatic. In summer, the North Pole is tilted so far towards the Sun that it never dips into darkness — the Sun just circles the horizon for months. This is called the Midnight Sun. In winter, the opposite happens: the pole is tilted away so steeply that the Sun never rises at all. This is polar night.
And what about the stars? As the Earth orbits the Sun, the night side of Earth faces different directions in space. This means the constellations we can see change throughout the year — in winter, Orion is visible; in summer, Scorpius. The stars themselves haven't moved — we have.
You've just read about the key ideas — now go deeper on one of them. Choose a topic card below and use a reliable website (BBC Bitesize, NASA Kids, National Geographic) to find out more.
Which countries experience it? How long does it last? Find a specific example.
When is the longest day in the UK this year? How many hours of daylight does it get?
Name a winter and summer constellation visible from the UK. Why do they change?
What is polar night? How long can it last, and which countries experience it most?
Answer each question below. You'll get instant feedback after each one — read it carefully even if you got it right.
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