Why day turns into night

Each evening the Sun seems to go down and set. Is the Sun moving?

The idea

No. Earth turns, so the Sun only seems to move.

Earth rotates. It spins on its own axis, like a top. The axis is an imaginary line through Earth's centre.

One full spin takes about 24 hours.

The side facing the Sun has day, because sunlight reaches it. The side facing away has night. No sunlight reaches that side.

Earth turns, and we turn with it. So the Sun seems to rise and set.

Try the lab to finish this lesson.