Bright lights at night dim natural world

by Maeve Sowles

For those of us drawn to the outdoors, the night skies offer a realm of beauty and fascination. December and January have early sunsets and the longest evenings for watching stars. If we have clear weather, winter constellations are brilliant. The bright stars of Orion, Taurus, Canis and Gemini sit on each side of the Milky Way. The ancient Greeks gave mythical names we still recognize to these constellations. Our ability to enjoy these glorious stars connects us with ancestors who lived centuries ago. Many of earth's early cultures were inspired by celestial events as seen in Anasazi petroglyphs, Egyptian and Mayan ruins, Stone-henge, Chinese jewelry and Japanese paintings. Babylonian and Arab mathematicians charted distances in the skies. Early Polynesian navigators used their knowledge of the night skies to find pinpoint islands on the open ocean. This timeless connection with the experiences of our ancestors is available to us every clear night.

One challenge to astronomy is the light pollution from our cities and towns. Even in rural areas, yard lights and highways mask the light from stars. The satellite image from the New York blackout dramatically shows the US continent at night. (1) There are very few truly dark areas.

Our own enjoyment is not the only issue with light pollution. Birds use stars as a directional cue during migration. Night-migrating birds can become confused by illuminated structures, causing them to deviate from their route. The extra energy needed to regain their course increases mortality in weaker birds. Birds also collide with tall lighted structures. Many other animals that depend on nocturnal activities for survival are damaged by light pollution. Sea turtle hatchlings are confused by lights at beaches and crawl toward the light rather than into the ocean. This increases their vulnerability to predators. Mammals, insects, amphibians, plants and fish have all suffered deaths due to artificial lighting.

Many cities are adopting ordinances to minimize light pollution. Using directional lighting, shielding upward radiating light and reducing high wattage bulbs can restore the visual pleasure of the night sky, while at the same time reducing energy costs. Chicago now dims their skyscraper lights during spring and fall migrations to help save birds. (2) Zurich, Switzerland (3) and even small towns in Idaho (4) are committed to reducing light pollution. The International Dark Sky Association, (5) maintains an informative web site with interesting examples of the effects of light pollution.

Oregon has areas that are still good for stargazing: Crater Lake, eastern Oregon, the southern Oregon Coast and the Cascades. The UO Pine Mountain Observatory is a good source of information for stargazing opportunities. (6) We can keep our skies dark for our own aesthetic pleasure and to enhance the survival of wildlife.

I urge you to reduce your outside lighting, (use lower intensity, shielded lights for shorter periods of time) so we can enjoy clear, dark, starry nights.

Web site references

1. NOAA images
2. Chicago
3. Zurich
4. Idaho
5. The International Dark Sky Association
6. UO Pine Mountain Observatory