WASHINGTON — A cosmic question occurs to some people in far-flung lands, a common thought expressed in many tongues: Where has the night gone?
In the Middle East, Muslim clerics say it's difficult to find the faint sliver of the new crescent moon because of glare from the ground. In the Arctic, native elders say legends drawn from the winter sky are becoming harder to pass on because village lights obscure heavens inhabited by spectral caribou and departed souls.
From the Himalayas in India, retired geologist S.B. Misra thinks back on the Hindu star mythology he learned as a child and observes: "The clarity of the sky appears to vary from place to place and seems to have decreased with time in half a century."
Call it light trash. As development spreads, so, too, do lights of civilization. The dark frontier recedes.
"It creeps up on you gradually," says University of Virginia astronomer Phil Ianna, who some nights can see the city of Richmond's glow, 70 miles away, from his hilltop observatory.
Some sky-watchers worry the nightscape primeval is fading from sight. Leaders in a half-dozen states, scores of communities and groups internationally are acting to bring it back.
They are pushing for restrictions on light that shines wastefully into the sky, illuminating nothing but the bellies of birds, as they like to say.
The International Dark-Sky Assn. draws astronomers and other stargazers together to fight celestial glare. For untold millions, it says, the "spectacular view of the night sky that our ancestors had on clear dark nights no longer exists."
Look up in an average suburb or city and on some evenings not much more than the moon, some planets and a smattering of the brightest stars might be visible. It's like watching a slide show in a lighted room, says David Crawford, president of the association.
Sources vary--it could be the distant glow of a 24-hour superstore playing on the clouds, a conglomeration of highway lamps erasing the stars, a neighbor's security light scattering its harsh rays, or all of that and more put together.
To be sure, vast reaches of the planet are still untainted by man-made light, even in the United States, a nation so developed that its precise outline is visible in nighttime satellite photographs etched by the piercing lights of cities, suburbs and highways.
But light trash can intrude in unexpected places. Muslim clerics say modern lights and air pollution can make it hard to find the new moon that begins the holy month of Ramadan the next day.
Two hundred miles north of the Arctic Circle, in the Canadian town of Igloolik, pop. 1,200, researcher John MacDonald says local lights are getting in the way of legends of the Inuit, or Eskimos, who see stars of the Big Dipper as representing caribou.
"When I interview Inuit elders here, it's the first thing they point out, that they don't see the sky anymore because of the obscuring glare of the street lights," said MacDonald, author of "The Arctic Sky: Inuit Astronomy, Star Lore and Legend."
"The anathema of amateur astronomers everywhere has hit remote parts of Canada," he said. "This affects the whole transmission of knowledge."
The International Astronomical Union plans to discuss light pollution at a United Nations-affiliated conference in Vienna, Austria, in July. "Plainly visible from space, this light not only obliterates the faint signals reaching us from the universe, it also represents the useless waste of much fossil or nuclear fuel," the union says.
In the United States, Maine has enacted glare controls, as have all Arizona counties and many cities from St. Augustine, Fla., to San Diego. Typically, regulations call for shielded highway lamps to keep light from scattering upward, require homeowners to direct security lamps to the ground or ban billboards illuminated from below.
New Mexico has a new law requiring most outdoor lighting that is installed starting next year to be shielded. The law also prohibits future installation of mercury vapor fixtures, considered glare-prone.
"If we don't start doing something now, eventually it's going to be like living in Massachusetts, where the sky is orange at night," said anti-glare activist Mike Stebbins of Manchester, N.H.
The Goethe Link Observatory, discoverer of many minor planets from its bluff outside Indianapolis, lost much of its research value a decade ago because of night light from spreading suburbs. Now a brilliantly illuminated gas station six miles away has made it still harder to see the universe, astronomers say.
The Mt. Wilson Observatory overlooking the Los Angeles Basin also can't see galaxies so well at night--except when a cloud cover sweeps in below the mountaintop and seals off the ground glow.
Amateur astronomers, too, wonder if backyard stargazing is what it used to be, says Elizabeth Waagen at the American Assn. of Variable Star Observers.