Why can't you see the stars in urban areas?

Question

What is it about the streetlights etc that stops you being able to see the stars?

Answer 1

The common term for this effect is "light pollution". Simply put, since light - especially from cities - doesn't just go straight up but expands outward in something akin to a bubble around a city, it can cause your irises to constrict, which then prevents the much fainter starlight from being interepreted by your brain.

In other words: the abundance of city light drowns out the starlight. It's a lot like trying to listen to a mp3 when a concert speaker is blaring some other music right at your ears.

Answer 2

Two types of pollution affect the visible light that can be seen. One is the atmospheric pollution of peoples. All types of engines throw up alot of junk, cars,lawn mowers, go carts, motorcycles, boats, air traffic, lotsa stuff.
Then there is the light pollution, in a congested or any area that has a number of humans the light that is used at night has an effect on the optics.
It is kinda fun to see it, go out to a very remote area, (while you still can) , makeing certain that there is littl;e if any cloud coverage, and take a gander at the stars. Identify every near and far galaxy, star or set of objects in the night sky. Take a polaroid if you can.
Also look towards the area in wich you reside, you will see a dome of light pollution in the area over your town/city.
Then walk out your back door and do the same, try looking for the same stars and stuff that were so easily visible in the remote area.
Is all basically just your eyeball adjusting to the mass of light around you that causes or does not cause some far away lights to be visible.

Answer 3

Air pollution - there is too much haze (gunk) in the air for the light to penetrate well
Light pollution - stars are very far away and you need a clear night sky with a lot of contrast to see them well
The streetlights block the starlight in a similar way the sun does - they are so bright, that the stars aren't visible to us.

Answer 4

Because you need a dark sky to see stars. The street lights light up the sky so far and I presume reflects back (a little bit like the sun). When the sun is up you should still be able to see stars but because of the glare from the sun you can't. I know what I mean but I've had a few to may red wines tonight. Hee Hee.

Answer 5

To see stars clearly you need to see them in the dark. Streetlights create a field of light that is stronger than the light from a star so the starlight does not reach your eyes and cannot be seen.
Thats why only the brightest stars can be seen in citys, they are the only ones whose light can penetrate

Answer 6

Light pollution. Imagine this: You are in your house with all the lights on, you look out the window, (its dark) you can't see anything. But if you turn off your houses lights you can. Same thing with stars and urban areas. The stars are in the dark, while your in "the house".

Answer 7

It's mainly light pollution.

The stars really are pretty faint points of light. We see them with really specialized receptors in the retina. If any ambient light gets in the way, your pupils do not open up as wide as they would if you were in a really dark place.

Even if you live in a dark rural place, if you go outside after being in the house lights, it takes up to 30 minutes for these special receptors in the retina to kick in, and it is worth waiting for this, even if it is a really cold night.

It is the same reason stars are not visible by day.

Did you know the planet Venus is at times visible in daylight? It is quite surprising when somebody points it out to you.

Answer 8

It is due to the light from the streetlamps obscuering the night sky. I was in Tunisia a few years ago, and the sight of the stars there is a totally different view from the one of Urban Britain. Breathtaking is one word I could use.... I suggest though, that you take a trip out to the countryside one night & without the hindrance of streetlamps, I think you will notice the difference.

Answer 9

Because of the light pollution, mainly caused by street lights.

Street lighting is a major cause of energy wastage because much more could be done to direct the light downwards where it is needed instead of radiating it off into space. It is also arguable that many street lights are unnecessary, but local authorities are understandably reluctant to cut back because of the flak they would take if a serious crime or accident occured where the lights had been switched off.

Answer 10

Streetlights do stop you from seeing the stars because since that light is closer to us, we can't see the far-away lights because streetlights block the natural light! (Remember, stars are far away from us, so it's harder to see them.