Why the stars overhead do not twinkle?

Answer 1

Because a planet isn't a star...

A planet reflects light, it doesn't create it.

Because of their closeness to us.

Stars twinkle due to tiny variations in the earth's atmosphere. A star appears so small to us that even one tiny dust particle gettinng in the way can make the star blink out, just for the tiny fraction of a second that its light is blocked. The net result of dust particles and variations in the refractive index of the air is to make the star dance around, and also vary in brightness.

A star is so far away that it always appears as a point, even seen through a telescope with high magnification. A planet is much closer, and is seen as a disc even through a low powered telescope. When a dust particle intercepts the light coming from a planet, it only blocks a fraction of it. The brightness of a planet, averaged over the whole disc, doesn't vary much. The planet does still dance around, but again the effect is very localised. If you view a planet through a high powered telescope you can see one or more features of the planet move relative to the rest.

So that must mean solar dust happens outside of our solar system.Mmmm.

They are nearer to earth and hence we receive a greater amount of light and, therefore minor variations in the intensity are not noticeable

Answer 2

Because Stars appear as a single point in the sky, because of the great distance between us and them. This single point can be highly affected by atmospheric turbulence. Planets, being much closer, appear as disks.

We can't resolve them as disks with our eyes, but it still averages out as a more stable light in the sky.

Answer 3

The twinkling effect is caused by starlight passing through the atmosphere. Overhead, the atmosphere is thinnest so there is little twinkling (although there is some). As you get lower down, the atmosphere is thicker and so the stars twinkle more. This is especially so in the early evening as the Earth is calling down and the atmosphere shimmers a lot due to heat. And it's worse in cities where there is a lot of pollution. But if you go outside in the early morning hours, the air is stiller and there is less tickling. Also if you go up higher there is less twinkling and this is why so many of the BIG observatories are high in the mountains.

Answer 4

The stars overhead do twinkle if you look closely enough. That is because they are so far away and are point sources of light creating diffraction. Planets do not twinkle since they are much closer

Answer 5

Well, they shine all the time, but during the daytime our atmosphere prevents us from seeing them because it is lit up by the Sun's light and the stars are too dim.

Answer 6

They do, but less than in summer ...

the "twinkle" is due to turbulence in the air between you and the star,

and the turbulence is often less on a clear winter night.

Answer 7

Twinkling is caused by the atmosphere. Stars overhead pass through less of our atmosphere, so it is possible that you notice less twinkling in that case.