Stars shine like tiny points of light. They seem to move or change brightness. We say they twinkle.
Before starlight reaches our eyes, it passes through Earth’s atmosphere. The atmosphere has moving areas of warm and cool air.
These areas bend light. Because the air is always changing, the path of the light changes again and again. Stars then appear brighter, darker, or slightly moved.
The star itself is not quickly turning on and off. Its light only seems to dance after it passes through our moving atmosphere. From above Earth’s atmosphere, stars do not twinkle in the same way.