Home
Stewardship of Night Sky Brightness
The Night Sky in Chacoan Culture
How We Measure Night Sky Brightness
Accumulated Results of Sky Surveys
The Night Sky Program at Chaco
Image Library
Related Links
Contact Us
 STEWARDSHIP OF NIGHT SKY BRIGHTNESS  The night sky at Chaco Culture National Historical Park has long been recognized as a precious natural resource - and one that is in more and more danger of being lost as we spend more and more of our energy on developments that are lit to a degree that they literally outshine the stars in the sky in terms of brightness. Chaco's managers have responded by placing shields and motion sensors on lights that are required in the park - and wherever feasible, by simply doing away with lighting altogether. By designating the night sky as a natural resource in its General Management Plan of 1993, Chaco has become an inspiration and role model for other national parks, institutions, and communities throughout the United States. Indeed, New Mexico night sky advocates seeking to justify night sky legislation pointed with pride to Chaco as a way of gaining support.  Much of the ceremonial life of many of the peoples here on
earth may be timed to the events seen in the heavens above. It has
long been known that many New World cultures have amassed large
bodies of knowledge concerning astronomy. Sometimes agricultural
practices make use of seasonal patterns reflected in the sun's
movement, or of constellations in the night sky, to time activities
such as planting or harvesting. The observational powers of people
who lived intimately connected to all aspects of their natural
environment are known to be acute and multifaceted. In 1970,
researchers called "archaeoastronomers" began bringing their unique
perspective into Chaco Canyon, hoping to reveal the astronomical
secrets of the ancient builders. Many sites in Chaco Canyon have
been selected by such researchers as places that offer examples of
ancient knowledge of astronomy. Some researchers go as far as
asserting that the architecture found in the great buildings of
Chaco is especially aligned to solar and lunar events - not only the
individual buildings themselves, but even alignments between
buildings that cannot easily be perceived.While many of these ideas remain controversial, what cannot be questioned is the extreme degree of darkness that today characterizes Chaco Canyon's night sky. Yet that darkness is threatened by the encroachment of civilization on Chaco Canyon, and the rampant use of unshielded artificial light sources. These 'threats' are represented by three separate and distinct entities: Sky Glow, Glare and Light Trespass. Sky Glow is the 'dome' of light you see above cities. Our experts can, at the present time, detect Farmington, Albuquerque, Gallup and Grants ... and sometimes smaller established villages. Even a modern gas station/convenience store can create a sky glow detectable by our ccd cameras from miles away. Glare is the excess brightness of a light source against dark skies. When your eyes are adjusted to the dark, and you run across an intersection with extremely bright lights, you're experiencing glare. Interstate highways and highway improvement projects are placing powerful lighting closer to Chaco Canyon. Light Trespass is *any* excess light that spills beyond a light's intended use. Mining and energy extraction companies utilize banks of floodlights that spill over to Chaco Canyon. The general public perceives brightly-lit areas as being 'safe' areas. But research shows that dark skies are completely compatible with being safe and secure. Overlighting and light pollution in general wastes our nation's energy resources, and increases costs for all of us. The focus should be on efficiency of lighting. Using only what is necessary, and taking advantage of modern technologies to keep the impact on the night sky to a minimum. Here are some general suggestions:
 For many people, seeing a truly dark night sky for the
first time here in Chaco Culture National Historical Park is thrill
enough. For others, the added knowledge that they are looking up
into what is essentially the same sky that was seen by the Chacoans
a thousand years ago provides a direct and almost spiritual link
between our modern world and the time of the ancients. All who view
Chaco's night sky find it fascinating and confirming to realize that
even though we may be using new methods and tools such as telescopes
and computers to view the night sky today, we are looking to the
heavens for at least some of the same reasons that our forbears did:
To better understand the nature of the larger world around us, and
our place in it. And the awe that these perspectives awaken in
visitors provide the main impetus behind continuing efforts at Chaco
Canyon National Historical Park to preserve the glory of its dark
night sky. |