The main cause is the Earth’s atmosphere. Stars do not really twinkle; they just appear to twinkle when seen from the surface of the Earth. Stars twinkle in the night sky because of the effects of our atmosphere. The globe is surrounded by many layers of air in the atmosphere. When starlight enters our atmosphere, it is affected by winds in the atmosphere and by areas with different temperatures and densities. The light goes in waves. This causes the light from stars to twinkle when seen from the ground.
Why do stars twinkle?
