Canyon of the Eagles Dark Sky Protocol

In order to allow the maximum benefit of this dark sky observing site all users must take steps to eliminate unnecessary light. Adaptation for best night vision is a gradual process that requires from approximately 20 minutes to nearly an hour. Most people don't reach their best night vision for about 30 minutes.
Unfortunately, dark adaptation is easily lost with exposure to any level of white light. Each event of exposure to white light (or bright light of any color) will restart the period of dark adaptation. Small amounts of red light may be tolerated without significantly degrading vision provided that the light source is not bright and does not shine into the eyes.
Area of Control:
The Dark Sky Area includes (but is not limited to) all of the following within a contiguous area, regardless ofuse: fields, trails, roads, parking lots, picnic areas, campgrounds, and the interior and exterior of all structures, including buildings, restrooms, and chemical toilets. In addition, the Dark Sky Area includes all approach roads from a "No headlights permitted after dark" sign onward toward the observing site.
Persons/Entities Affected:
All persons present in the Dark Sky Area are bound by the Dark Sky Protocol, including park employees, contractors, and visitors.
Periods of Dark Sky Area Control:
This time shall be called the Dark Sky Period. Every night, when 10% or more of the sky is not overcast and at least one observer is present, shall require adherence to the Dark Sky Protocol. The Dark Sky Period extends from the end of Nautical Twilight calculated at the observatory location through the start of Nautical Twilight the following morning.
If it is raining, the Dark Sky Area Protocol will be lifted.
If it is more than 90% cloudy but with the potential for clearing, all persons in the Dark Sky Area shall be asked to voluntarily comply with theDark Sky Protocol to minimize dark adaptation time when conditions permit observing.
During a medical emergency or other bona fide emergency situation, the DarkSky Protocol may be temporarily lifted for those directly involved, to ensure safety and prompt appropriate response to the emergency.
Dark Sky Rules:
The rules in this section shall apply in the Dark Sky Area during the Dark Sky Period. All white lights shall remain extinguished. All bright lights of any color shall remain extinguished. No light of any kind shall be emitted from vehicles except for amber parking lights and red brake lights. Parking lights and brake lights are permitted only while the vehicle is in motion. Vehicle lights specifically prohibited are headlights, daytime running lights, fog lights, search lights, backup lights, dome and trunk lights, and entry and courtesy lights. Vehicles shall be parked such that the reverse gear (backup lights) will not be needed upon entry or exit. Only red lights of minimal brightness may be used in the Dark Sky Area. Lights shall be directed downward at all times. Lighting for charts or accessories must be shielded and confined only to the target area. Computers of any kind must be shielded with red foil or confined, to eliminate all light visibility beyond the actual user.
Campfires, cookstoves, lanterns, and other devices with open flames are prohibited.
Trailers, tents, RVs and other equipment must not emit any non-red or bright light visible from the outside.

Persons moving vehicles from the observing field or the parking lot during the Dark Sky Period should be considerate of other observers, for example by giving a warning before moving, and must obey all rules about car lights being off.

(See also Star Party Etiquette.)

Austin Astronomical Society
P.O. Box 12831, Austin, TX 78711


Supporting members of the Astronomical League, Night Sky Network and International Dark Skies Association.

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