1. First international dark sky city
Flagstaff, Arizona

2. What is a dark sky city?
A “Dark Sky City” is a city that adopts the light ordinance to prevent deterioration of the night sky for astronomical research and observation
Flagstaff, Arizona was the very first “International Dark Sky City ,” this occurred in 1958
Today’s dark sky defenders are the Flagstaff Dark Sky Coalition which was founded in 1999

3. Why should we preserve the night sky?
All life on Earth evolved with a natural day and night cycle, over millions of years.
Humans have been inspired by the night sky for over ten thousand years.
If we take away the dark of night many plant and animal species will be lost; human health can also be negatively impacted
Future generations will not experience the night sky like our ancestors once did
We are genetically rooted to ponder upon the stars
The night skies are a human inspiration

4. Light Pollution is an issue
  artificial light introduced into the natural night sky. This unwanted light reflects back onto the planet
Can affect human hormones and natural sleep cycles
Using excess light at night is a waste of energy
But light pollution interferes with living systems
For example: It can deter birds from natural migration routes
Sea Turtles can loose site of their natural route in the ocean from the reflection of the night sky
Seasonal Plant Cycles can be disturbed from excess light

5. Before & After Light Pollution

6. Dark Sky Rating

7. What can you do as a Citizen?
As a concerned citizen you can buy certain products to make your home lighting night-friendly
Some home lighting you can aid to reduce light pollution:
Floodlights — Aim them downward as much as possible. Motion sensors should only “see” areas near your house and not turn on for branches blowing or pedestrians walking by in the street.
Porch / Garage Lights — What’s that glaring “carriage” light doing on your house? Are you planning to drive it down the street?
Bulb Types — Choose from 8 Incandescent (including Halogen) and 4 Compact Fluorescent (CFL) lamp types.
For all house lights, consider yellow sources (“bug” lights) to minimize glare, sky glow, ecological disturbance
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8. References