Why does a planet not twinkle?

Question

We are taught that when we see a star at night,it twinkles because atmospheric disturbances interfere in its path.But,why doesn't it disturb the light coming from the planets?

Answer 1

Stone me..........you've got a mix of reasonable answers here and some from the kindergarten (or the deep mists of time). What do they teach in schools these days - clearly not basic astronomy or physics !

The twinkling effect (properly called stellar scintillation) is caused solely by the light being distorted as it comes through the Earth's atmosphere. The thicker the atmosphere is (or the more polluted) the more the twinkling effect. So stars closer to the horizon will appear to twinkle more.

The reason you don't tend to notice that planets twinkle is generally because most people will view them when they high in the sky on very clear nights. Venus is a prime case in point as the morning or evening star.

The reality is that planets will twinkle just like the stars (and, if you look closely, you will see high flying aircraft lights twinkle as well in the right conditions).

Answer 2

LET'S SUM IT ALL UP!!!

1. Twinkling is solely caused by the turbulent air above you.

2. When viewed from space - NOTHING TWINKLES.

3. Because stars are "point sources" it doesn't take much
turbulence to make them twinkle.

4. Planets are not "point sources" (they resolve into discs) and
therefore don't appear to twinkle unless they are viewed
through very turbulent air- esp. close to the horizon.

5. Have you ever looked down a highway in the heat of a warm
summer day and seen it appear to wave back and forth.
It appears this way because of the turbulent hot air rising
from the concrete. This is essentially the same process
that causes stars to appear to twinkle.

Answer 3

The stars appear very small in size,while the planets appear bigger.The star may be considered as a point source and the planet an extended source.The planet can be considered as a collection of a large number of point-sized sources of light such that they nullify the twinkling effect.Hence the turbulent atmosphere is unable to cause sufficient variations in the light flux entering our eye from the planet.

Answer 4

Stars, except for the Sun, although they may be millions of miles in diameter, are very far away. They appear as point sources even when viewed by telescopes. The planets in our solar system, much smaller than stars, are closer and can be resolved as disks with a little bit of magnification (field binoculars, for example).

Since the Earth's atmosphere is turbulent, all images viewed up through it tend to "swim." The result of this is that sometimes a single point in object space gets mapped to two or more points in image space, and also sometimes a single point in object space does not get mapped into any point in image space. When a star's single point in object space fails to map to at least one point in image space, the star seems to disappear temporarily. This does not mean the star's light is lost for that moment. It just means that it didn't get to your eye, it went somewhere else.

Since planets represent several points in object space, it is highly likely that one or more points in the planet's object space get mapped to a points in image space, and the planet's image never winks out. Each individual ray is twinkling away as badly as any star, but when all of those individual rays are viewed together, the next effect is averaged out to something considerably steadier.

The result is that stars tend to twinkle, and planets do not. Other extended objects in space, even very far ones like nebulae, do not twinkle if they are sufficiently large that they have non-zero apparent diameter when viewed from the Earth.

Answer 5

Stars twinkle because we see them from the bottom of a bundle of air.
Stars appear to be very small, much smaller to our eyes than each of these air bundles. So when the light gets bent, the apparent movement of the star is larger than the size of the star in the sky, and we see the star shifting around. Our eye can't really detect that motion, because it's too small. What we see is the light from the star flickering. That's why stars twinkle.

why don't planets twinkle? It's because planets are bigger. Well, actually 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.

Answer 6

My guess would be because the light reflected off a planet is more intense than the light from a distant star

Planets don't twinkle because they aren't made of fire.

The reason stars twinkle is because they are made of fire and of course fireballs glow and their flame movements causes the 'twinkle'.

Planets on the other hand, are just made up of gas and other mysterious items.

Answer 7

Planets are not self-luminent . they do not have or give out light . If at all they are visible , it is because of the reflection of the light fom the sun. and this being much less in inensity , they are invisible to naked eye. the light reflected from the surfaces of the planes being of insi=ginificant intensity , they do not seem to be disturbed by the atomospheiric air on the earth..so they are not visible at all to the naked eye .but htose which are closer to the earth , like venus and mars whichg look like the stars themselves , do appea to be twinkling like stars as the light from them are somewhat closer to the that coming from the distant self -luminant stars .

Answer 8

see a planet is not an star to twinkle.

Answer 9

Don't know what discount textbooks you bought homey, but (some of) the planets in our solar system are close enough to spot the twinkle by eye my friend. For the thumbs down here, take an Astronomy class and see Venus or Mercury for yourself WITHOUT a telescope. Listen to Lipsiot, he's a smart mo-fo.

Answer 10

there r many factors working simultaneously behind dat. bt d main reason is dat planets r too nearer of us than other stars. the light comin 4m the stars reaches us after getting afeected by d gravitational pull of many other celestial bodies. whereas since the planets r closer 2 us. they get affected by comparatively less force. thats y the planets dont twinkle bt d stars do