For three billion years, life on Earth existed in a rhythm of light and dark that was created solely by the illumination of the Sun, Moon and stars. Now, artificial lights overpower the darkness and our cities glow at night, disrupting the natural day-night pattern and shifting the delicate balance of our environment. The negative effects of the loss of this inspirational natural resource might seem intangible. But a growing body of evidence links the brightening night sky directly to measurable negative impacts . . .

From the Website of the International Dark Sky Association

Artificial light has enabled human progress, freedom to learn, travel, and work beyond sunrise to sunset. Too many millions of people still struggle without electricity.

But that progress for most of the human race has come with a price: the shadow side of lighting, as it were. A century ago, children could look up from backyards in American towns and see the Milky Way. Now, industrial light, signs, street lighting and the reflected glare of our cities block our awe-inspiring views of the night heavens. Not only is our view of God’s magnificent creation blocked by pervasive artificial light, but there are adverse effects on ecosystems, wildlife, human health and safety. We can support the Dark Sky movement, whose work ranges from public policy and dedicated dark sky places to certifying outdoor light fixtures that minimize glare, enabling us to enjoy the benefits of artificial light while preserving and restoring the darkness of night.

Even inside our own homes, we can be mindful of the way we use artificial light that can disrupt our sleep patterns and health, suppressing the production of melatonin and other natural hormones. Getting natural light in the morning and yellow or red wavelength lights in the evening, minimizing late night screen time, and sleeping in the dark, can all be beneficial to health and well being. (Confession: Your guide is a bit of a night owl and sometimes works on this site online late at night. At least after that I take care to sleep in a dark room.)

Here is the Sierra Club‘s guide to the best places for Dark Sky stargazing in the Western Hemisphere.

Featured Image: Milky Way viewed from Theodore Roosevelt National Park by Justin Kern via Flickr

Watch a short film on Losing the Dark, or return to the Gateway of Darkness.