Day and Night
Turn Earth and follow one place through a day.
One Earth. Two skies.
Turn our planet and follow one place into the sunshine and back again.
Looking down from above the North Pole. Drag the globe or use the slider and buttons.
Follow the sunshine
Move the yellow marker with Earth. Does your place face the Sun or turn away?
Your place faces the Sun and receives daylight.
Why does day become night?
Earth spins around an imaginary line called its axis. The half facing the Sun has daylight; the half facing away has night. Your place moves between them as Earth rotates.
One solar day is about 24 hours. The Sun does not switch off at night, and Earth does not need to go around the Sun to make a day.
Try it at home · words to know
With an adult, shine a torch at a ball. Put a small sticker on the ball and slowly turn it. Watch the sticker move into and out of the light.
Rotation means spinning around an axis. The terminator is the moving boundary between the lit and unlit sides.
My discovery notebook
Save your current observation. It stays on this device.
No observations yet.
Quick quiz · Why is it night?
What makes day change to night?
Think like a scientist
1. What happens on the opposite side of Earth while your place has daylight?
2. How long does it take the model to turn halfway? How long for a full turn?
3. Why can a place have night even though the Sun is still shining?
Simplified model: view from above the North Pole. Sizes and distances are not to scale. The model omits twilight, seasons and variations in day length, and uses an idealised 24-hour solar day.
What is happening?
The side facing the Sun has daylight. As Earth turns, a place moves into and out of sunlight. One full turn takes about 24 hours. Move the marked place from noon to midnight and back to noon.
Simplified model: View from above the North Pole; tilt, seasons and twilight are omitted.
Questions to explore
What will children learn?
Explains day and night using Earth's rotation relative to incoming sunlight.
How does it work?
The side facing the Sun has daylight. As Earth turns, a place moves into and out of sunlight. One full turn takes about 24 hours.
What should we try?
Move the marked place from noon to midnight and back to noon.