Although, in the preceding paragraphs, I’ve mentioned that light pollution stretches out for about 150km in every direction, the sky starts to get noticeably clearer the moment you leave a city or town. Light pollution may not be noticed quite so much by the younger generation, but those may remember what a truly bright, starry sky used to look like. Each of us can implement practical solutions to combat light pollution locally, nationally and internationally. "It's not as dark as being in the country but it's dark enough to see a pretty large fraction of the stars," says Watson.

So how do city slickers get to view the wonders of the sky?

In fact, some of the best skies that can be found are within about 120 km of Melbourne.

However (obviously), when observing, light pollution does limit what you can observe, so it may just be a matter of being selective about what you view on any given night. Let's face it, singing 'Beneath our radiant Southern Triangle' really just doesn't have the same ring to it. Surprisingly, this might not be as far away as you think.

Many Australian cities have a tremendous amount of light pollution. A growing number of scientists, homeowners, environmental groups and civic leaders are taking action to restore the natural night.

How to cite this article, National Oceanic and Atmospheric Administration. If you think there are lights near you that are having a harmful effect, contact your local council.

Light may be detected as far as 1,000 meters down in the ocean, but there is rarely any significant light beyond 200 meters.

Such a minuscule amount of light penetrates beyond a depth of 200 meters that photosynthesis is no longer possible. Use these social-bookmarking links to share How far away from city lights do you need to be to escape light pollution?. Author: NOAA

Astronomers have techniques for filtering out natural sky glow because it occurs at very specific wavelengths, but what can keen urban stargazers do to combat light pollution? It allows you to photograph the entire sky and not just the individual objects that you happen to be able to see.

to someone you know: Since a majority of the world’s population lives in built up areas, light pollution is becoming more and more of an issue, especially as the built up areas expand farther and farther out into the countryside. Using a UHC filter near a city will make the object look at a little better but just keep in mind… NOTHING beats a darker sky , I understand and agree that registration on or use of this site constitutes agreement to its User Agreement and Privacy Policy.

(Source: iStockphoto). Narrowband filters are amazing in astrophotography (and amazingly necessary).

So with light pollution stretching out as far as it does, how do we deal with it? The ocean is divided into three zones based on depth and light level.

These lighting fixtures cut-off all light above the horizontal plane and so they not only reduce light pollution they also save energy as well.Do something about light pollution in your local area. While the majority of sky glow is caused by artificial lights some of it is caused by natural phenomena such as moonlight or dust in the solar system.

They allow you to take spectacular images of deep sky objects without having to worry about either light pollution from cities or the moon’s glow. This zone contains the vast majority of commercial fisheries and is home to many protected marine mammals and sea turtles. ‘Photic’ is a derivative of ‘photon,’ the word for a particle of light. It's hard to get starstruck with lights shining in your eyes. Australian Standard 4282 deals with the control of the obtrusive effects of outdoor lighting and some local governments also have restrictions on the use of outdoor lighting. There are three ways inefficient lighting can cause light pollution. It's an Aussie icon, but worsening light pollution in urban areas could cause our mighty Southern Cross to suffer a most un-Australian fate. In this zone, the intensity of light rapidly dissipates as depth increases. Use this form to email 'How far away from city lights do you need to be to escape light pollution?' Beyond astronomy, there are many compelling reasons to tackle light pollution, argues Watson.

Light pollution and astronomy really don’t go hand in hand at all.

By designing and using better lighting and shielding lights to prevent light going upwards into the sky, we'll not only keep astronomers happy but also help protect these animals, and reduce our energy use and carbon footprint.

And so the cycle continues. In the case of the O-III filter, it only lets the light from ionised oxygen in while blocking pretty much all other light.

The light pollution of a city as large as Melbourne can still be seen from 150km (93 miles) away, and it is clearly visible in a long exposure photo. Even in a city like Sydney there's a pocket of darkness only 20 kilometres from the CBD in the Pittwater area. However regional stargazers shouldn't underestimate the local effects of light pollution even in smaller towns.

How far does light travel in the ocean? Although there will still be some light produced from these sources, your skies will still be quite clear (editors note: we will not be held accountable if any of you run out and start attacking power plants). On a recent visit to Kalgoorlie in Western Australia, which has a population of approximately 30,000 people, Watson found stargazing in the centre of the town impossible because of the local lights.

Instead, just look at the moon or the planets, bright double stars (there are quite a few bright ones up there in the sky). How far away from city lights do you need to be to escape light pollution? "It's certainly true that light pollution has a very damaging effect on nocturnal species and migrating birds," he says. In short, drive an hour or so away from your city in a direction that takes you away from other major light sources, and chances are, you’ll get some pretty good viewing. Iv'e heard it can travel over 50 miles depending on how much.

Another good way to somewhat beat light pollution is with the use of filters. Specific categories of light pollution include light trespass, over-Illumination, Glare, Light Clutter, and Skyglow.A single offending light source often falls into more than one of these categories.

Although some sea creatures depend on light to live, others can do without it. This doesn’t have to be too far either. The reason for this is that they only allow very specific wavelengths of light though.
One of the more common type of filter for general observing is called a “Light Pollution Filter.” The actual name for this type of filter is a. To Sum: Observing can be done in light polluted areas, it can be done in cities, and even without any filers at all.

Take Melbourne as an example, housing estates are popping up everywhere.

So is light.

http://www.abc.net.au/science/articles/2009/03/26/2527197.htm?
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Fortunately, concern about light pollution is rising dramatically. Many Australian cities have a tremendous amount of light pollution. High levels of sky glow reduces the amount of contrast between the dark sky and celestial objects to the point where only stars of the highest magnitude can be seen by the naked eye. So are X-Rays. Somehow manage to disrupt all the power in your city for a night so that the only lights working are battery operated and cars.

"In a sense it was as bad as being in the middle of a big city, but it was just the lights that were in the local area that were doing the damage," he says. Light pollution affects every citizen. Only a small amount of light penetrates beyond this depth.