Keeping the night sky dark

To ever-increasing numbers of people, losing the darkness of night to light pollution is a growing concern. And, while the cause of the problem has been clearly identified, the reason for their worry is multifaceted.

Our ancient ancestors must have had an incredibly transparent view of the night sky. The stars probably shined so brightly that it may have seemed that they could reach out and touch them. And the wealth of information they gleaned from their observations helped them make sense of the world in which they lived.

Over the past two or three hundred years the industrial revolution has increased the amount of suspended particulate in the atmosphere - mainly in the form of hydrocarbons from burning fossil-fuels - that has dimmed our view of the night sky. Recent advances in technology have helped reduce this pollution, and in many regions of the world the air is cleaner as a result.

But the number-one reason we are losing our dark skies, by far, is due to increasing light pollution. Photographs taken over time by satellites, such as the International Space Station, show the spread of more and brighter lights. And the vast majority of this light is wasted in illuminating the atmosphere before heading out into the vastness of space.

Adverse impact of brightening night skies on astronomy, both professional and amateur, is undeniable. Astronomers at once-remote observatories can no longer conduct certain kinds of research that require the blackest of skies. The opportunities for amateurs to make meaningful contributions to science are also becoming more limited. That is why cities and towns located near large observatories have adopted stringent outdoor lighting ordinances. These include Tucson and Flagstaff in Arizona and Hilo, Hawaii, among many others.

Enter the International Dark-Sky Association (IDA). The IDA is a United States-based non-profit organization whose mission is "to preserve and protect the nighttime environment and our heritage of dark skies through quality outdoor lighting." They recognize that light pollution is the result of outdoor lighting that is not properly shielded, allowing light to be directed into the eyes and the night sky.

Improper lighting can also cause light trespass when it is directed into areas where it is not wanted, such as a neighbor's yard and windows.

IDA's principal approach is to raise awareness about the value of dark, star-filled night skies and encourage their protection and restoration through education about the problems and solutions.

But you don't have to be a stargazer to bemoan the increase in light pollution. A brighter night sky interrupts the behavior of certain types of wildlife. According to Michael Mesure, executive director of the Fatal Light Awareness Program, artificial lighting seems to be taking the largest toll on bird populations. Nocturnal birds use the moon and stars for navigation during their bi-annual migrations.

"When they fly through a brightly lit area, they become disoriented," said Mesure.

Still others see improper lighting as a safety issue. Bright and/or badly shielded lights around roads can partially blind drivers or pedestrians and contribute to accidents. According to Mario Motta, president of the Massachusetts Medical Society, "...glare from bad lighting is a public-health hazard - especially the older you become. Glare light scattering in the eye causes loss of contrast and leads to unsafe driving conditions, much like the glare on a dirty windshield from low-angle sunlight or the high-beams from an oncoming car."

The use of LEDs (light emitting diodes) for illuminating streets and roadways has its advantages and disadvantages. They use very little energy and can dramatically reduce operating costs. In addition, they have long life spans and attract fewer nocturnal insects than other types of light sources.

On the flip-side, however, they put out enough glare to cause visual discomfort when they are not properly shielded. According to an article in the Journal of Environmental Management, LEDs "may well exacerbate known and possible unknown effects of light pollution on human health."

Conditions here in Sisters are still pretty good - we can see the Milky Way under dark skies. But unless our citizens and city planners start taking light pollution seriously, we will eventually lose our dark skies. Sisters has a robust outdoor lighting ordinance that has the potential to keep our night skies dark. But unless it is implemented, and enforced, it can do no good.

Let's begin dealing with light pollution as well as we do other forms of pollution to keep the natural beauty that surrounds us as pristine as possible.