Since humans first looked skyward, the night sky has remained virtually unchanged. For ages, people around the globe have found the heavens a source of inspiration for stories and art. What has changed in recent decades is the ability of most people to actually see the stars that comprise the night sky. Once visible from backyards across the country, light pollution obscures the Milky Way from two out of three Americans today.Monitoring an Important Resource
National parks offer places for people to connect with the natural world, including the night sky. The 'natural lightscape' provided by dark night skies is important for plants and animals, as well. Wildlife depend on the cover of darkness to hunt for food and in turn to hide from predators. Light pollution can also affect the natural cycles of plants. To better understand the impact of light pollution on this key resource, Craters of the Moon is one of many parks that have participated in a night sky assessment. These studies provide baseline data on light pollution and have found that it, like other forms of pollution from cities and developed areas, is encroaching on national parks. Although Craters of the Moon still hosts some of the darkest night skies of any national park unit, light pollution from far-off cities such as Idaho Falls and Twin Falls does impact the monument's night sky.
Good Lighting vs. Poor Lighting
Outdoor lighting provides many benefits. It brings better visibility to roads and security against crime. But improperly used lighting wastes energy and degrades the night sky. For instance, a typical unshielded fixture loses half of its light upward in direct waste. The good news is that unlike many other sources of pollution, light pollution is easily reversible. Fixtures that direct light towards the ground - where it is most needed - protect natural lightscapes and reduce the amount of energy lost upward and to glare. Other principles of night sky friendly lighting include:
· Use outdoor lights only where they are needed.
For more information on efficient outdoor lighting, visit the NPS Night Skies webpage. The two-fold benefit is a darker night sky and savings in your wallet!
Enjoying the Night Sky at Craters of the Moon
Did You Know?
Watch out for bombs! Before they cooled, volcanic bombs were hot globs of lava that were hurled from volcanoes along the Great Rift. They form a variety of interesting shapes described as "breadcrust", "spindle" and "ribbons" by geologists. More...