when looking at the night sky, how does one tell the difference between stars and planets?

Answer 1

Stars "twinkle". Called astronomical seeing, it is the blurring and twinkling of astronomical objects such as stars caused by turbulence in the Earth's atmosphere.

Planets do not twinkle because the relative disk size is larger so there is less blurring effect from the atmosphere.

Answer 2

It's all about the "twinkle". Stars are so far away that their light appears to come from a very small point. The planets are close enough to look like a tiny disk. Light passing through the atmosphere is jostled around by the air, sometimes more and sometimes less depending on conditions, but always to some degree. And the conditions change from second to second. As a result, starlight gets smeared out over a larger area than the point from which it is coming, appearing to dance around. This is what causes stars to twinkle. The same thing happens to light from the planets, but because they cover a larger area in the sky, the jostling doesn't cause them to twinkle.

So look carefully for a few moments at an object, and you'll be able to tell whether it's a star or a planet simply by whether or not it twinkles.

Incidentally, if you look at the moon through a telescope, you may notice that the surface seems to "swim" a little bit, as though you were looking at it through a watery film. This is the same thing, light being jostled around by the atmosphere.

Now, if you want to know which planet is which, that requires learning about their various characteristics (brightness, color, where and when they can be seen).

Answer 3

The term 'planet' means 'wanderer'. If you watch a star from night to night, it will stay in the same position relative to the other stars. A planet will move in the sky in relation to the stars. This was noticed thousands of years ago-long before we found out that some planets are larger than the earth.

Some planets cannot be seen without a telescope (Uranus, Neptune), while others can (Mercury, Venus, Mars, Jupiter and Saturn). The ones that are visible generally don't 'twinkle' when you look at them in the sky-this is because they are not pointlike light sources like stars appear to be. Also, they tend to be brighter than most stars. Once you get familiar with which stars are where, it is quite easy to know whether you are looking at a planet or not.

Answer 4

I will assume you are using the naked eye. The answer is, you can't. If you know the position of a planet, then you only know it's a planet, because that's where it's supposed to be. Planets and stars look pretty much alike to the naked eye. The only other way to tell the difference is by movement. To do this with the naked eye takes the patience of a saint.

Answer 5

I am assuming you mean with the naked eye? Planets do not twinkle like stars do - they look like little steady lights and transit differently to stars. Venus is very bright and can be seen very early in the morning - Jupiter has a greenish glow to it and Mars has a Orange hue to it - Saturn can also be seen with a greenish blue glow. Good luck with looking

Answer 6

Planets are brighter.

Venus is the brightest star in th night sky.

Also known as the "Dawn-Star" or the "Evening Star".

It is the only one you can always see....... there are a few times of the year when you can see 12 more, but it is very infrequent.

Answer 7

Oh.. that`s a wonderful experience... to see the sky in the night.. and I also had the same question.. I have read that planets don`t have their own light, so, they receive sun`s light, in the other hand, stars are like "little suns".. they have explotions, that we see as "twinkles"..

Answer 8

Planets don't twinkle like stars.

Answer 9

first of all planets wud appear a little bigger in size and also wen you keep observing continously for atleast 7 days u wud find that planet change their position very quickly whereas stars do not