It is no simple task to get away from the lights. Urban sky glow, the dome of light hanging over all cities of any substantial size, extends for miles and miles. For example, it easy to see the sky glow of Phoenix, Arizona, from more than 100 miles away. The sky glow from Los Angeles, California, is visible from an airplane 200 miles away. How many dark spots are left in the urban corridor in the Northeastern part of the United States? Even in the most remote portions of North America, there are dusk-to-dawn lights blaring into the darkness. The light from even one of these causes significant light trespass a mile or more away. I challenge anyone reading this to find a mountaintop or plateau in the continental United States where there is no trace of light pollution visible somewhere on the horizon.

In any event, those who say "Just go to the countryside if you want to see starry skies" might as well say the loss of trees and flowers in our cities is not important either. Why have urban parks? Just go out of town to see some grass, flowers, or trees. It shouldn't be necessary to go out of town to see these. If we can't have enough sense to plant trees, shrubs, and flowers all around our cities, we can at least have enough sense to plan for parks and preserve those green areas left. Why not have the same attitude toward dark skies? We are not asking people to turn off their lights. We are asking them to shield the lights, use proper wattage for the task, and turn off unneeded lights.


Light pollution affects all of us. It robs the professional astronomer of his or her livelihood and hinders the amateur's enjoyment of their hobby. It deprives us all of one of nature's grandest wonders -- the night sky. Many persons who claim this is of no importance have never gone far out of town to see what they are missing. Those who grow up in an urban environment may never see the Milky Way. How can someone miss something he has never seen? The loss of this part of nature desensitizes us to other insults upon the environment. This is like saying the loss of a virgin forest is of no concern because most people won't get to see it anyway, and there are plenty of trees for lumber. The loss of wildflowers, polar bears, wolves, whales, and other threatened species, to be honest, won't affect the average person. Their loss only directly impacts biologists, or those more in tune with the natural environment than in the environment we humans create. After all, humans have done very well without mammoths, mastodons, and passenger pigeons.

However, no one supports the extinction of magnificent animals. Why should we permit the loss of our skies? Not only does light pollution dim the stars for the astronomer, but it dims them for all persons. Everyone has a right to the stars. Light pollution takes away one of our most ancient heritages and it represents visible destruction of the environment in several ways: the dome of light hanging over most cities blots out the stars; electricity is generated and wasted to light the night sky -- light needs to be on the ground not up in the sky; the wasted electricity represents wasteful burning of coal, oil, and natural gas; the byproducts of these wasteful burnings show up as acid rain, smoke, and carbon dioxide emission; strip mining and underground mines ravish the land to produce the coal for the wasteful burnings; runoffs from this mining pollutes rivers and streams. Thus, light pollution does far more than inconvenience a few astronomers. It is a most harmful assault upon our environment. It affects us all, and all of us ought to be concerned about it.

For more popular myths about the pervasiveness of Urban Sky Glow see IDA Information Sheet #42, "Some Lighting Myths".