Day and Night Rotation

Earth spins continuously on an imaginary line called its axis. This spinning movement is called rotation. Earth makes one complete rotation every 24 hours — this is what gives us a day and a night. The side of Earth facing the Sun experiences daytime; the side facing away experiences night.

How Rotation Creates Time-of-Day Changes

• Sunrise — as Earth rotates, your location moves into sunlight; the Sun appears to rise in the east.
• Morning — the Sun climbs higher in the sky as your location moves more fully into sunlight.
• Noon — your location faces the Sun most directly; the Sun is at its highest point and shadows are shortest.
• Afternoon — the Sun begins to move lower as your location slowly rotates away from direct sunlight.
• Sunset — your location rotates away from the Sun; the Sun appears to set in the west.
• Night — your location now faces away from the Sun; the sky is dark.

Other Effects of Rotation

• Shadow length — shadows are longest in the morning and evening when the Sun is low; shortest at noon.
• Temperature — the side facing the Sun is warmed; the night side cools down.
• Wind patterns — the spinning of Earth also influences global wind patterns (the Coriolis effect).