Crusaders seek return of dark skies

Satellite view of United States at night

TUCSON, Arizona (CNN) -- We take it for granted, the well-lit night. But it is a relatively new phenomenon. Besides confusing animals and disorienting the human body, artificial night lighting hampers amateur and professional sky watchers.

One group of scientists in Arizona knows what light pollution can do. Their optical instruments require much more time to soak in the faint light levels necessary to detect distant objects in the universe.

The mountains of southern Arizona boast a number of major observatories. But in the valley below the shimmering city of Tucson threatens their view.

The city imposed light control rules in the 1970s, in large part to keep the sky dark for the sake of astronomy.

Even though the metro population has grown 40 percent in the last decade, the artificial light that is scattered above has grown less than 20 percent.

But while the lights are staying relatively low in Tucson, it is a different story in the rest of the world.

The most comprehensive study of light pollution found that it affects 99 percent of the population in the United States.

It also found that two-thirds of all people in the country live in places where they can no longer discern our own galaxy, the Milky Way, with the naked eye.

David Crawford, leader of the International Dark Sky Association, considers the statistic a sobering one.

"Mankind and everything else grew up with the cycle of day and night, and that tends to be disappearing," he said.

David Crawford of the International Dark Sky Association

Crawford, a retired astronomer, and the Tucson-based association is leading the charge to reverse the trend.

A key recommendation of the dark sky activists: use shields on the tops of outdoor lights so the light does not shine up into the sky.

Dark sky improvement measures often use energy more efficiency, saving their users a significant amount of money.

"You can save billions of dollars in energy worldwide every year by using light instead of wasting it," Crawford said.

Some in Tucson think the light police are going too far by putting limits on lighting advertising and commercial signs that grease the economy.

"Globally, I'd put it that it's much more serious to see the stock market fall than have a falling star go unnoticed," said Don Dybus, vice-president of Clear Channel Outdoor.

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His billboard company has gone to court to fight a new ordinance that Dybus said would force costly changes in lighting. Clear Channel already voluntarily turns off the lights on its billboards around 11 p.m.

"You have the non-business community making all the complaints. Well maybe they ought to learn more about business and share with us what their needs are, instead of running to the city council and saying (we're) bad," Dybus said.

Several cities and towns have passed light pollution ordinances. The Arizona Senate passed a proposal for the entire state, but the House rejected it on Wednesday.

For the dark night crusaders, however, there was one recent international success. In February the Czech Republic became the first country to enact national legislation with provisions designed to eliminate light pollution. It goes into effect in June.

But it is a fact of modern civilization, as satellite images dramatically reveal, that for most people the sky never becomes truly dark. And a starry, starry night has become a thing of the past.