are stars in the sky a light source?
963524
I remember one winters night in the west of Ireland there was no moon and no cloud cover and a fresh white covering of snow over the fields. I walked out down the lane and the whole place was lit up light day from the starlight alone. Absolutely beautiful.
556627
A shooting star is not actually a star.  It is a meteor.\n\nA meteor is the light you see when a meteoroid comes in contact with the Earth's atmosphere.  The "ram pressure" of this object, which is usually rock or rock + iron, smacking into our atmosphere creates heat, and the meteor begins to burn.\n\nWhen our Solar System was forming, there was a lot of junk left over.  If our Earth's orbit intersects with this junk, it will burn in our atmosphere.  \n\nMost meteoroids are tiny (dust and pebble sized) and burn up before they can reach the Earth.  Some hit the atmosphere the wrong way and skip across it like a stone thrown to skip across a lake, and eventually escape, albeit somewhat smaller now.  Some manage to hit the Earth.  There's one in the Adler Planetarium in Chicago that is huge, about three feet long and a foot through the middle.  (When they make it to the groud they are called meteorites.)\n\nMeteor can come one at a time, but there are also meteor showers, times during the year when you can expect to see a lot of meteors (10-80 per hour).  This happens when the Earth passes through the trail left by a comet.  Meteor showers are named for the constellation from which they appear to radiate.  The most famous is the Perseids, which radiate from Perseus, and are associated with the comet Swift-Tuttle.
515706
The atmosphere is made up of several layers,each one with a varying density.Thus,the speed of light differs in different layers of the atmosphere and the light gets refracted(deviated from its path when it travels from one medium to another)when passing from one layer of atmosphere to another.Due to this refraction of light in the different layers of the atrmosphere,stars appear to twinkle
491513
During clear night, there are about 6000 (six thousand) visible stars from each hemisphere of the Earth. However, it is for sure that there is no certain way of calculating the exact number of "stars up there", because of explosions of old stars and creations of new stars, that occur almost every minute, somewhere in the universe.
752575
The scientific name for the twinkling of stars is stellar scintillation (or astronomical scintillation). Stars twinkle when we see them from the Earth's surface because we are viewing them through thick layers of turbulent (moving) air in the Earth's atmosphere. \n\nStars (except for the Sun) appear as tiny dots in the sky; as their light travels through the many layers of the Earth's atmosphere, the light of the star is bent (refracted) many times and in random directions (light is bent when it hits a change in density - like a pocket of cold air or hot air). This random refraction results in the star winking out (it looks as though the star moves a bit, and our eye interprets this as twinkling). \n\nStars closer to the horizon appear to twinkle more than stars that are overhead - this is because the light of stars near the horizon has to travel through more air than the light of stars overhead and so is subject to more refraction. Also, planets do not usually twinkle, because they are so close to us; they appear big enough that the twinkling is not noticeable (except when the air is extremely turbulent). \n\nStars would not appear to twinkle if we viewed them from outer space (or from a planet/moon that didn't have an atmosphere). \n\n\n---------------------------------------------------------------------------------\nStars, 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).\n\nSince 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.\n\nSince 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.\n\nThe 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.\n-------------------------------------------------------------\n\n\nI can be more specific, sure. Remember that just like a computer screen, your eye is composed of a certain number of "pixels," each represented by a single light-receptor cell in your retina. If two (or more) points of light are close enough such that they are focused on the same receptor cell in your eye, you will experience them as a single point of light. This is referred to as the "resolution" of your eye, or any telescope for that matter. \n\n\nNow, a star on the sky is in a true sense a single point of light. All the light comes through the atmosphere in exactly the same direction, through exactly the same atmospheric turbulence, and thus is bent in exactly the same way. So when it gets to your eye, the amount of light you see coherently varies. It also strikes (primarily) only a single receptor in your eye. \n\n\nOn the other hand, light from a planet is different. Each of a few receptors in your eye sees a large number of light rays coming f
441849
Well the simplest way has already been said... the sun rises in the east and sets in the west... so you can work out north from that.... \n\nBut as you mention the stars are we to assume you are trying to find direction at night?\n\nAgain there are many country ways - like the moss growing on trees and prevailing winds etc - but I personally wouldn't rely on this.\n\nSilly thought but if you have a map and can see any landmark or town lit up at night you can get your direction.
13842
They are a cluster of stars in the north, that light up the sky beyond imagineing. City goer's have no clue of the beauty the stars can have due to light pollution. Light pollution makes the stars not shine as bright or as many. There are much much much more stars visible than what i see where i live. also, northern lights is a strand of marijuana. Very very good marajuana. some say best in the world, it grows in canada or upper penninsula of michigan
330462
Sorry to disappoint you, but light from stars and the sun is not crooked. it is straight. Therefore, straight lines do exist in nature.
620559
If stars twinkle due to the atmosphere, then why the planets and moon do not twinkle?\n\nTwinkle, twinkle, little star, how, I wonder, what you are?\n\nOn a clear night only about 2000 stars are visible to the naked eye.\n\nThe nearest star, Centauri, is at a distance of 4.3 light years; that is at a distance of about 2, 60,000 times the distance of the sun.\n\nEven this nearest star appears to be a point from earth.\n\nTherefore, a point image is formed in the retina our eye, that is they fall on very few rods of our eye. \n\nEven a sight turn of eye ball will shift the image position in the retina. This causes the twinkling effect of stars.\n\nBut if we view a star continuously we can’t feel the twinkling effect. \n\nHowever, some stars vary their brightness periodically; they are long period variables and short period variables. Their period varies from a week to months.\n\nHence they are not the cause for twinkling.
99849
Light is one form of electromagnetic radiation, I think it is pretty obvious how light is important to astronomers.\n\nBut sometimes just seeing the object isnt enough, we want to know more.\nFor example, if we wanted to know the chemical composition of a far-off star we can do this by analysing the emmision spectrum of the star.  When electrons around the nucleus of particular atoms get excited they jump up to higher energy levels.  When the electrons fall back to the ground state, the give off a photon of light (not necesarily in the visible spectrum) of a specific wavelength.  We can analyse that light given off by a star and compare it to the ligh given off by known elemetns, from this we can figure out what stars are made out of.\n\nThe electromagnetic spectrum is so broad, there are so many things we can learn by studying the EM waves coming in from outer space.
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.
75380
There is a surprisingly simple answer to your great question: Each month we see different stars, so to answer for a specific night of the year at your specific location on Earth depending on your eyesight and how bright the city lights around you are might be hard to pin down. \n However there is a magnitude scale that astronomers use to describe how bright objects in the sky are. Without getting into details on how that works, the average human being can see down to about magnitude 6 ( brighter objects have lower magnitude until you reach zero. Then even brighter objects use negative numbers for their magnitudes which is a bit weird, isn't it?) Therefore, all you have to do is get a map of the whole sky showing anything brighter than magnitude 6 and count the stars. If you are fortunate to be away from bright city lights and you can see the Milky Way, you would be really surprised to know that you can only see about 6,000 stars. That's the number of stars above magnitude 6 in the entire sky.
39095
No. \n\nStar:\nA self-luminous celestial body consisting of a mass of gas held together by its own gravity in which the energy generated by nuclear reactions in the interior is balanced by the outflow of energy to the surface, and the inward-directed gravitational forces are balanced by the outward-directed gas and radiation pressures\n\nPlanet:\nA nonluminous celestial body larger than an asteroid or comet, illuminated by light from a star, such as the sun, around which it revolves.\n\nSo, stars are self-luminous (have their own light) and are stationary. Planets don't produce their own light and revolve around a star.
61059
Solar rays, that always come to earth.  U r able to see them becuase of ur position in earth, North Pole.\nBut the lights are just solar rays.
77447
The brightest star in the sky is Sirius (aka the Dog Star) and it is sort of bluish, and iridescent.  It flashes so many colors that I have many times had people convinced it was a plane and bet me money it wasn't a star, only to see it sitting quite still among the stars for hours.  THis star would have probably been on the western horizon pretty late, like around 2 or 3 am (it's usually rather high in the south when I go to work at 10pm).\n\nMars, being rather red, is also quite visible recently, and would be hovering near the horizon also quite late.  Mercury is always near the sun, and is likely to be seen in the west just after sunset (but I can't say for sure, since I haven't seen it recently--it's usually already set by the time I wake up for work).  And it seems like I recently saw Venus being quite right, and it should be setting a few hours after sunset.\n\nIf you give the color and the time, I could give you a better answer.
11418
The scientific name for the twinkling of stars is stellar scintillation (or astronomical scintillation). Stars twinkle when we see them from the Earth's surface because we are viewing them through thick layers of turbulent (moving) air in the Earth's atmosphere. \n\nStars (except for the Sun) appear as tiny dots in the sky; as their light travels through the many layers of the Earth's atmosphere, the light of the star is bent (refracted) many times and in random directions (light is bent when it hits a change in density - like a pocket of cold air or hot air). This random refraction results in the star winking out (it looks as though the star moves a bit, and our eye interprets this as twinkling). \n\nStars closer to the horizon appear to twinkle more than stars that are overhead - this is because the light of stars near the horizon has to travel through more air than the light of stars overhead and so is subject to more refraction. Also, planets do not usually twinkle, because they are so close to us; they appear big enough that the twinkling is not noticeable (except when the air is extremely turbulent). \n\nStars would not appear to twinkle if we viewed them from outer space (or from a planet/moon that didn't have an atmosphere).
650511
None, they up in the Sky, best seen at night. The Earth does revolve around a Big Star that can actually be seen in the day and not night. Make for a good Word Play/Riddle question. ;-D