Why do stars twinkle?
In: Other
This is called scintillating.
The stars are so far away it is as though the light comes from a single point in the sky. This makes any small perturbation in the light much more noticeable.
The atmosphere is constantly moving and changing pressure and humidity. This refracts (bends) the light at varying amounts so the star constantly looks like it is changing brightness.
Planets on the other hand, do not scintillate. This is because they are close enough to the earth that their light comes from an area in the sky rather than a single point. So if you ever see a bright star in the sky that isn’t twinkling then you instantly know it’s a planet. It’s cool being out at night and instantly being able to recognise Jupiter or Venus.
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