Why stars shines at night but planets don't?
612427
Nice question....stars shine because it is millions of light year away from us...in the case of planets its nearer than stars...not sure though..but i think so...
83573
As all the others said, the sun is a star, and you see it every day. Sometimes, in early morning or in late afternoon, some of the most prominent start may be visible, mostly on the horizon.\n\nAll the stars which you can see by night is still there during the day, but the sun's light is so bright that we cannot see past its brightness to where the stars are.\n\nI once heard in an astronomy class that it is able to see a star in the day, but the light of the star has to fall directly in the mid-center of your eye, and that takes some doing.\n\nLastly, there are certain occasions where stars are visible during the day. I remember when I was in primary school, the Planet Venus (although not a star) was visible next to the moon right in the middle of the day. If Venus can be visible at that time, then why not any other star?\n\nHope I could help you...
373960
This has been pretty well answered but I thought I'd clarify.\n\nThe Sun is the name of our solar system's star, the star we call home.  (Similarly the Moon is technically the name of Earth's only natural satellite, other planets have natural satellites which we commonly call "moons").  Other stars have different names (like Vega).\n\nWe are just finding extrasolar planets (planets that orbit other stars) and it is likely that there are many stars out there with planets and even solar systems (more than one planet orbiting them).  However it is also very likely that many stars will not have any planets at all.\n\nIf you are interested in this, here is a fun website about extrasolar planets: http://planetquest.jpl.nasa.gov/index.cfm
300540
Observed from Earth’s surface, stars appear to twinkle because the atmosphere bends light on its way to the ground.  Stars are so far away that they appear as points of light in the sky, so when the atmosphere bends light from a star, it actually prevents the light from the star from reaching our eyes entirely—in other words, the tiny beam of light from the star that could reach our eyes at that point in time gets deflected away from our eyes briefly.  Thus, stars appear to twinkle on and off.  At one instant, a star’s light reaches your eye; at the next instant, it doesn’t.\n\nThe sun is simply too large to twinkle.  Yeah, one beam of light may get scattered away (perhaps to enhance the blueness of our sky), but the beam of light next to it will make it to your eyes, and on average, the whole sun appears nice and bright and untwinkling in the sky.  (Likewise, the moon doesn’t appear to twinkle, either.)\n\nIn space, there’s no atmosphere, no air to change the trajectory of light reaching your eyes (assuming your eyes are safely enclosed in a spacesuit with the rest of you), so the stars will not twinkle.  \n\n\nRyan Wyatt\nRose Center for Earth & Space\nNew York, New York
1029405
You've almost answered your own question:  Stars are "stationary" sources of energy (nuclear) and give off light.  Planets do not and they orbit stars.
471007
Because stars are not very bright. In the day time, scattered sunlight makes the sky a bright blue, brighter than the stars. Even bright streetlights are enough to overwhelm the dim starlight.
166889
I live in a small town in the midwest and make it a point to go out and do some stargazing.  The street lights do wash out some of the dimmer stars, but there are still a lot of stars to see.  Going out into the countryside will reveal a lot more stars.  Not only the stars though, in the last week I have also seen Mars, Venus, Saturn, Jupiter and Mercury..and the most fantastic cresent moon in the early morning.  If a person can get up into the mountains at night (no mountains where I am at), the sky is very full of stars...way too cool.
226485
You reminded me of my childhood days. I used to ask my father the same Questions.\n\nClouds don't go any where during night. They are still there it only that there is not enough light for us to see them. Remember when you see moon light we see those clouds around or sometimes the moon hiding behind the clouds.
970874
In your context brightness and luminosity do mean the same thing, and that is the total amount of light given off by the star.\n\nHowever brightness can sometimes mean surface brightness, which is luminosity per unit area of the star. So a red giant has a low surface brightness, but the large surface area of the star gives a large total luminosity for the star as a whole.
91699
Stars are burning like our sun. Planets aren't burning like our earth. Planets usually orbit around suns.
805182
It's always daytime in space. Unless you are stuck behind a planet or a moon or something else, then it's dark as hell... The spining of the Earth creates day and night.
995538
They are still up there in the sky. You cannot see most of them because they are too dim, compared to the brightness of the sky.\nThe blue sky we see is the scattered light from the sun, and it tends to wash out the stars.\nHowever you CAN SEE  STARS in the daytime. Take a trip to your local planetarium, they can take you out and show you what stars are visible in the daylight.\n\nThere are a couple of stars that are bright enough to be visible in the daylight.\nFirst off, Venus is easily seen in the daytime sky, Jupiter is sometimes visible, but very hard to find (in my experience anyway) and the star Sirius is also easily found in the daytime sky. During an eclipse you can often seen dozens of stars in the sky before the sun comes back out and the sky gets bright again.\n\nAnd of course there is one bright star that is easily seen in the daylight, OUR SUN!
527724
All stars except the Sun appear to the human eye as shining points in the night sky that twinkle because of the effect of the Earth's atmosphere. Interferometer telescopes are required in order to produce images of these objects. The Sun is also a star, but it is close enough to Earth to appear as a disk instead, and to provide daylight.\n\nStars are not spread uniformly across the universe, but are typically grouped into galaxies. A typical galaxy contains hundreds of billions of stars. The majority of stars are gravitationally bound to other stars, forming binary stars. Larger groups called star clusters also exist.\n\nAstronomers estimate that there are at least 70 sextillion (7×1022) stars in the known universe [1]. That is 70 000 000 000 000 000 000 000, or 230 billion times as many as the 300 billion in our own Milky Way.\n\nThe nearest star to the Earth, apart from the Sun, is Proxima Centauri, which is 39.9 trillion kilometers, or 4.2 light years away (light from Proxima Centauri takes 4.2 years to reach Earth). Travelling at the orbit speed of the Space Shuttle (5 miles per second -- almost 30,000 kilometers per hour), it would take about 150,000 years to get there. Distances like this are typical inside galactic discs, where the Sun and Earth are located. Stars can be much closer to each other in the centres of galaxies and globular clusters, or much further apart in galactic halos.\n\nCheck the wikipedia link below.
1095018
Not a simple question, but  this is two main reasons.\n\n1) Brightness of the Star Play a part.   Assume uniform Atmosphere.\n\n2) The Atmosphere also another part.  Assume stars of the same brightness.\n\n1)  Brightness of the Star Play a part.\nBrighter the Star, less likely the twinkle.   Look at the Moon, does it go Bink Bink?  Too Bright.\n\nBut Dimer stars, under the same Atmospheric conditions, may Bink.\n\n2) The Atmosphere also another part.\nThe Atmosphere is not uniform, look at the sky during the day, sometime, it clear blue,  and other time clouds mass abound.\n\nThe Atmosphere is like a thin soup, with some sliver of bread in it,.  using that example, when the Stars of the same brightness is in the Sky,  imagine when a sliver of bread blocks lightly one of the stars, thus one Bink, and another don't.\n\nIt Real life, Stars are not of the same brightness, and the Atmosphere is not always uniform.  making the issue complex.
973173
There are more stars than we can count.  Most of them have planets.   Most of those planets have moons.
160778
Twinkle twinkle little star\n\nThere aren't many nursery rhymes about astronomy. But 'twinkle twinkle little star' makes a useful point. We can tell which lights in the night sky are stars because they appear to twinkle. Planets, on the other hand, don't, they shine steadily in the sky.\n\nStars twinkle because they are very far away, and so appear as tiny points of light in our night sky. Some of this light is absorbed by moving air in the Earth's atmosphere, making the star appear to sparkle.\n\nPlanets, like Saturn or Jupiter, don't sparkle. This is because they are a lot closer to the Earth and so they look bigger in our sky than stars.\n\n\nThe Pistol Star is the brightest in the known Universe\n\nRather than being points of light, planets are small discs. As their light is more spread out, even if some of it is absorbed by our atmosphere, some of the light still filters through, so the planet doesn't twinkle. This means that you can tell the difference between a planet and a star without even needing a telescope, just by seeing if it twinkles!\n\nWeighing a star:\n\nAs for 'wondering what they are', starlight also contains an extraordinary amount of information that can answer that very question.\n\nWeighing a star isn't as difficult as it sounds as you don't need an enormous set of cosmic scales, just one equation. The more massive a star is, the more energy it gives off. So first of all, astronomers measure the star's 'luminosity', the rate at which it emits energy. Then they can work out its mass.\n\nMeasuring a star's temperature:\n\nOnce the mass of the star is known, you can calculate the temperature inside its burning core. Stars perform a delicate balancing act between gas pressure pushing outwards and gravity pulling inwards. Mathematical equations can be used to map this. Then by measuring the size and mass of the star, astronomers can calculate the temperature of the core.\n\n\nWhat's inside a star?\n\nEven more incredibly, just by looking at starlight astronomers can discover what a star is made from.\n\nThe light that we see is just one kind of radiation known as 'visible light'. Other kinds include X-rays, ultraviolet, microwaves, radio waves and infrared. Different stars give out varying amounts of these signals, known as their 'spectrum'.\n\nWhen measured, the spectrum appears as a series of bright and dark lines positioned at specific points or 'frequencies'. This is the blueprint of a star and provides a wealth of information about what is happening inside.\n\nAs elements are heated inside the star, they absorb and emit energy, creating a 'blip' in the star's spectrum. So the position and strength of these lines reveal what elements are inside the star. Stars are classified into 'spectral types' according to the shape of this spectrum.\n\nLooking back in time:\n\nAlthough time travel isn't physically possible yet, we can see back in time just by looking out into space.\n\nLight from the Sun takes 8 minutes to reach Earth. So we are seeing what the Sun looked like 8 minutes ago. Alpha Centauri, our nearest stellar neighbour, lags behind by 4.3 years. So, the further we look out into space, the further we are looking into the past.\n\nThe distance that light travels in a year is called a 'light year'. The furthest that astronomers have ever seen are about 12 billion light years away, from a time just after the Big Bang, when the Universe was just a baby.\n\nI hope this helps....\n\nDon
427453
Even on a cloud free night the atmosphere will still affect the infra red light as it descends to earth.\n\nEarth;s air is continuously moving, a ray of starlight is refracted in a random direction causing the star we see to twinkle. This twinkling is extremely irritating to astronomers as it blurs the images from telescopes, leaving the resolution of the largest observatories no better than that from a 10cm telescope. (Larger instruments are built to collect more light, producing brighter images but with the same resolution). The only way to entirely avoid this problem is to launch a telescope into space. This is why NASA built the Hubble Space Telescope.