Grades 3–5 · Earth & Space
How does Earth’s turning bring day and night?
Day and night happen because Earth turns. This turning is called rotation. The Sun lights the half of Earth facing it, while the half facing away is dark. A place on Earth's surface travels with Earth as it turns.
In the diagramSunlightEarth: north-pole viewRed dot = one placeRotationMarked place: Day
The marked place begins on the sunlit side. As Earth rotates, the place reaches the edge of daylight and then moves into darkness. Later it turns toward the Sun again. The place has not left Earth; Earth's turning carries it through the repeating pattern.
This daily cycle takes about 24 hours. Earth's journey around the Sun is a different movement and takes about a year. The picture separates the bright and dark halves sharply to make rotation clear. Actual sunrise and sunset include twilight, and daylight length also depends on location and season.
About this explanation
Starting knowledge: Recognize a globe and follow one marked place around a circle.
Sources
- NASA — Reference Systems: Rotation and Revolution