What is a planet?

There were 5 classical planets known to ancient stargazers: Mercury, Venus, Mars, Jupiter, and Saturn. They were all named after Roman gods or goddesses.

Planets Space Satellite Moon  - CharlVera / Pixabay
CharlVera / Pixabay

They were all bright objects that moved relative to fixed stars, but more slowly than comets did. Those objects or else, planets were known as wandering stars then.

Planets are mostly solid

Planets are usually not made of gas but rather solid matter. Planets shine by reflecting light from a nearby star like our Sun, in this case. Light from the Sun bounces off the surface of planets like tiny mirrors and travels through space to Earth where we see it as reflected sunlight. Although planets do reflect some of the light that hits them, most of it passes right through them because planets are not made of gas like stars. Because planets are solid objects, their appearance does not change when dust or other matter blocks our direct view of them.

What is a star?

A star is a ball of gas, mostly hydrogen and helium, held together by gravity in hydrostatic equilibrium. The surface of a star is a thin layer of gas that is so hot it glows. The light from the glowing gas comes to us as photons, which are tiny packets of energy.

What happens to light from the stars?

Now when light passes through glass or water, one can see that it also gets dispersed into different colors. This is why sunlight looks like a rainbow when we look at it through a prism. Thus you would expect that starlight would look like a rainbow too. But no! When starlight passes through Earth’s atmosphere, we do not see any color variation in the twinkling starlight, but rather just a white light that varies in brightness.

Stars Night Mountain Sky Space  - JosepMonter / Pixabay
JosepMonter / Pixabay

This is because stars are so far away that all their colors blend together to form white light. In fact, if you walk out of your house on a clear night and look up at the sky, you will notice that stars mostly appear white; you won’t be able to distinguish between their colors.

What is twinkling and how does twinkling occurs?

Twinkling is an optical phenomenon that occurs when light passes through the atmosphere. When light passes through the atmosphere, it gets bent and scattered because of variations in temperature and density of the air. These variations cause the image of a star to move around. This movement can be seen by our eyes and so the stars appear to twinkle.

Why do stars twinkle and why planets do not twinkle?
Why do stars twinkle and why planets do not twinkle?

As we look up into the sky, we see some objects appear to be steady points of light (the planets) and other objects appear to be points of light that seem to flicker or change brightness (the stars).

Stellar scintillation

The starlight passes through a much greater thickness of atmosphere before reaching our eyes; this atmospheric disturbance causes their images to flicker or twinkle, which we call “stellar scintillation.”

Location of the stars

Stars twinkle and planets don’t twinkle because of the different nature and locations of the two. Stars are very far away, and they are made up of very hot gas. Since they are so far away, they appear as points of light in the sky, when viewed from earth.

Because they’re so far away, their light has to travel across a long distance before reaching us. That long distance is filled with air, which acts as a lens for the light. The variable temperature and density of this air cause the starlight to bend in different ways as it travels through it, causing it to appear to twinkle.

As the photons travel through space they can be scattered or absorbed by particles of dust they encounter. This is why stars twinkle – because their light is affected by dust and other matter along the path between us and the star.

Distance of planets and stars

Planets on the other hand are relatively much closer to us in space, and they are made up of solid materials. So their light (reflected) doesn’t get distorted by air currents in a significant way, and hence they don’t twinkle.

On the other hand, the planets are much much closer than the stars and hence they do not twinkle. The planets do not have any twinkling effect because of their proximity to us.

Stars twinkle in the sky because they are so far away from us. The light from the stars has to travel through the atmosphere of Earth to get to our eyes.

The turbulence of the atmosphere

The atmosphere causes turbulence which bends and distorts the light as it travels. Because the amount of turbulence is always changing, the light appears to our eyes as though it is twinkling.

However, planets do not twinkle because they are closer to us than stars. There is less distance for the light to travel, and there is less turbulence in the air that can distort their light.

Stars twinkle because the Earth’s atmosphere acts like a lens and distorts their light, making it appear to change. Planets do not twinkle for the same reason.

The same effect happens with street lights: If you look at a street light on a windy night when the wind is blowing hard enough to make trees shake, then you will notice that it twinkles more than usual.

The brightness of a star

The apparent change in brightness of stars is caused by the fact that the atmosphere acts like a lens, bending, or refracting, light. As a result, the light coming from a star actually moves around in the sky slightly. This makes it look as though some parts of the star are brighter than others. When you look at planets or satellites through a telescope, they do not appear to change in brightness because they are so much closer and therefore easier to focus on.

Turbulence and twinkling

Stars and other objects in the night sky – twinkle because of turbulence in the Earth’s atmosphere. The atmosphere is constantly moving, so the layer of air that you’re looking through when you see a star changes all the time.

The star’s light goes through different layers of air, and some of those layers may be thicker or thinner than others. As a result, the light gets bent in different amounts as it travels through each layer, and your eye sees that as twinkling.

a star appears twinkling in the sky because of ?

A star appears twinkling in the sky because of light from other stars. As more and more stars are placed in the sky, they create a complex pattern of light that is not visible to the naked eye. When you look at a star, it may appear to be flickering or twinkling. This is because different parts of its surface are lighting up at different times, making the star appear to move.

A star appears twinkling in the sky because of light pollution. The light that we see from it is actually the light of many other stars. When we look at a star, we are seeing the light from that star, but it is being scattered by other objects in its path. This can make it appear as though there are many stars in one spot.

If you were able to look at a star through binoculars or a telescope, then you would see that it is not just one point; instead, it appears as a tiny dot that moves across the sky. This means that there are more stars than can be seen with naked eyes due to interference from other stars and even planets!


The twinkling effect of stars is caused by the movement of air in the atmosphere. It causes a distortion of the starlight that we see coming from the stars, which creates what we call twinkling. The light from the planets is not distorted like this, and so they do not appear to twinkle.

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