Losing the Dark

Have you ever heard of light pollution? Its the overuse of light at night. Nearly everyone on Earth has experienced it. Cities are bathed in light, but lights also encroach on the wilderness and rural landscapes as well. A study of light pollution around the world made in 2016 showed that at least a third of people on Earth have skies that are so light-polluted they cant see the Milky Way from their locations.   One of the most astonishing discoveries the astronauts on the International Space Station share with us is the widespread light pollution that covers our landscapes with the yellowish-white glow of lights. Even at sea, fishing boats, tankers, and other ships light up the darkness.   The Effects of Light Pollution Because of light pollution, our dark skies are disappearing. This is because lights on homes and  businesses are sending light up to the sky. In many places, all but the brightest stars are washed out by the glare of lights. Not only is this simply wrong, but it also costs money. Shining them UP to the sky to light the stars wastes electricity and the energy sources (mainly fossil fuels) we need to create electrical power.   In recent years, medical science has also looked into the link between light pollution and too much light at night. The results show that human health and wildlife are being harmed by the glare of lights during the night time hours. Recent studies have linked exposure to too much light at night to several serious diseases, including breast cancer and prostate cancer. In addition, the glare of light pollution interferes with a persons ability to sleep, which has other health consequences. Other studies show that the glare of lights at night, particularly on city streets, can result in accidents for both drivers and pedestrians blinded by the light of electronic billboards and superbright headlights on other cars. In many areas, light pollution is contributing to tragic loss of wildlife habitat, interfering with bird migrations and affecting reproduction of many species. This has reduced some populations of wildlife and threatens others.   For astronomers, light pollution is a tragedy. No matter whether you are a beginning observer or an experienced professional, too much light at night washes out the view of stars and galaxies. In many places on our planet, people have rarely seen the Milky Way  in their night skies. What Can All of us Do to Prevent Light Pollution? Of course, we all know that lighting is needed in some places at night for safety and security. No one is saying to turn off ALL the lights. To solve the problems caused by light pollution, smart  people in industry and science research have been contemplating ways to have our safety but also eliminate the waste of light and power.   The solution theyve come up with sounds simple: to learn proper ways to use lighting. These include lighting places that only need illumination at night. People can reduce a LOT of light pollution by shining lights DOWN to the places where they are needed. And, in some places, if light isnt needed, we CAN just simply switch them off. In most cases, proper lighting not only preserves safety and reduces the harm to our health and to wildlife, but it also saves money in lower electrical bills and lowers the use of fossil fuels for power.   We CAN have dark skies and safe lighting. Learn more about what YOU can do to light safely and reduce light pollution from the International Dark Sky Association, one of the worlds foremost groups seeking to solve light pollution issues and preserve safety and quality of life. The group has many useful resources for city planners, and both urban and country dwellers interested in reducing the glare of lights at night. They also sponsored the creation of a video called Losing the Dark, which illustrates many of the concepts discussed here. Its available free for download by anyone wishing to use it in their planetarium, classroom, or lecture hall.