Question

Why do stars twinkle on a clear night?

Answer 1

Light from stars crosses a very long distance to reach us and also passes through Earth’s atmosphere, which varies in temperature and density. Our atmosphere is very turbulent, with streams and eddies forming, churning around, and dispersing all the time. When light from stars passes through the atmosphere, it is bent due to refraction, which is why stars seem to twinkle when we stare at them.