Why Does the Sun Disappear at Night?

Think about this: last night it was completely dark outside. This morning, light flooded back in. Where did the Sun go? Did it really move across the sky — or is something else happening? Hold onto your answer, because what you are about to discover might surprise you.

The Sun does not move around Earth. Instead, Earth is always spinning — like a slow, giant top. This spinning is called rotation. Earth rotates on its axis, an imaginary line running from the North Pole to the South Pole through the centre of the planet. Earth takes 24 hours — exactly one day — to complete one full rotation. As it spins, different parts of Earth face the Sun at different times. When your part of Earth is facing the Sun, sunlight reaches you. That is daytime. As Earth keeps spinning, your part slowly turns away from the Sun. Sunlight can no longer reach you directly. That is night-time. Here is the amazing part: while you are having night-time, people on the other side of Earth are having daytime — right at the same moment! For example, when children in London are going to sleep, children in Sydney, Australia are waking up for school. The Sun has not moved. It is Earth that is spinning, carrying you in and out of the sunlight every single day.