Why do stars twinkle while planets don ?
Planets do twinkle. The twinkling isn’t an effect of what produces the light, but rather disturbances in our atmosphere. You have to keep in mind that the light that reaches us has to come through approximately 50 miles of atmosphere – from the mesosphere with its super-thin air to the troposphere, near the Earth’s surface. Temperature variations, humidity, particles – they all deflect light which creates the “twinkling”. On the brighter planets, this is less noticeable because they direct more light towards us, but it still exists. Even the moon shimmers because of our atmosphere – less so when directly overhead, but when it’s at an angle and its light passes through more air, the effect is quite noticeable.
