Why don planets twinkle?
It’s because planets are bigger. Well, really, they’re smaller than stars, but they are so much closer they appear bigger to us. They are much bigger in apparent size than the air bundles, so the smearing out of their light is much less relative to the size of the planet itself. Since the image doesn’t jump around, they don’t appear to twinkle. There’s always an exception though. In very turbulent air, even planets can appear to twinkle. The air is moving so rapidly and so randomly that even something as large as a planet can twinkle. This effect also plays with a star’s color. Blue and green light get bent more than orange and red, so sometimes in very turbulent seeing a star’s colors will rapidly change. This usually happens when the star is low on the horizon (so there’s more air for it to pass through). The brighter the star, the easier it is to see; Sirius, the brightest nighttime star, is often seen changing from green to red to orange and back, very rapidly. I’ve seen it myself
The simple answer is that the planets are much closer to our atmosphere than the stars. Since the stars are so far away, they are basically just a little point of light against a blackened sky. This pinpoint of light is easily bended from the distance that we view it. It’s the same reason that we don’t see our sun twinkle; it’s so close that is gives off a much broader ray of light, so it is not bent as easily. So the simple answer is that stars twinkle because we see them through moving air, which bends their light. In outer space, there is no atmosphere, so the stars do not twinkle. Even on our moon, they appear like the straight beam of light that they are. This stellar scintillation, the scientific name for twinkling stars, will only appear through out atmosphere of moving air.
This is because, even though they may look point-like to naked eyes, they are actually much bigger than the typical seeing. This means that you observe the combination of light which has passed through different atmospheric cells. Thus, the turbulent effects are averaged out, making the planets look steady. Hope this helps.
