Shadows, Days and Seasons
- Earth & Space
- Ages 8–11 · Grades 3–5
What you’ll find out
- Earth’s daily spin makes the Sun appear to cross the sky, so shadows change length and direction.
- Earth orbits the Sun once a year on a tilted axis.
- The tilt, not distance, causes the seasons, which are opposite in the two hemispheres.
No sign-up and no real names. In the lesson you check your understanding as you read, and practise until it sticks.
Shadows through the day
Earth spins once every 24 hours, which makes the Sun appear to travel across the sky. In the morning the Sun is low in the east, so shadows are long and stretch towards the west. Around midday the Sun is at its highest, and shadows are at their shortest. By evening the Sun is low in the west, and shadows grow long again, now pointing east. Long ago, people used shadow sticks, called sundials, to tell the time.
Why seasons change
Earth also travels around the Sun, and one full trip takes a year. Earth is tilted, a bit like a spinning top leaning to one side. For part of the year, your half of the planet leans towards the Sun: the Sun climbs high, days are long, and it is summer. Six months later your half leans away, the Sun stays low, days are short, and it is winter. When it is summer in the north, it is winter in the south.
Curriculum links: NGSS 5-ESS1-2 · England KS2: Earth and space · Cambridge Primary Stages 4–6: Earth and space · NCERT Environmental Studies, Classes 3–5