Module 02
How Day and Night Work
The Sun Stands Still
Every day, the Sun looks like it moves across the sky. You see it rise in the morning and set at night. But the Sun does not move. The Sun stays perfectly still in the middle of space. Earth moves instead.
Earth Spins Like a Top
Earth constantly spins around an invisible line going from its top to its bottom. We call this spinning rotation. Earth never stops spinning. It takes exactly 24 hours to complete one full spin — giving us one full day and one full night.
Light and Shadow
The Sun shines bright light toward Earth. But Earth is a solid ball — the light cannot pass through it. The Sun's light can only hit one half of Earth at a time.
The half facing the Sun is lit up: Day. The other half faces away from the Sun and hides in a large, dark shadow: Night. As Earth spins, your home moves from shadow into sunlight — then back again.
Step-by-Step
The Sun shines a bright beam of light directly onto Earth.
The light hits only the front half of Earth. People on this side experience Day.
The back half of Earth sits in complete shadow. People on this side experience Night.
Earth spins slowly. The dark side rotates forward into the light — a new morning begins.
Tactile Analogy
Stand and face a bright lamp. Your face is warm and lit — that is Day. Now spin your body slowly. When your back faces the lamp, your face is in the dark — that is Night. You moved, not the lamp.