A Dark and Starry Night
Do you remember when it was dark at night? I mean REALLY dark. Step outside your door an hour after sunset and you'll see what I mean. Between the neighbor's always-on security lights, the glaring streetlights, and the 24 hour stores around the block the night time sky isn't all that dark anymore. If you live in a city or even most towns it has become difficult if not impossible to see most of the stars anymore.
For most of us the sky is so light-polluted that we can't see the Milky Way anymore. When was the last time you were able to see the Milky Way, or a meteor shower? But when we head out, far out into the country the night sky comes clear again. Going camping far from any town may be the only way most of us can see the clear, dark night sky that our grandparents took for granted. Here are some ways that we can work to get our dark night sky back, other than a power outage.
The reason most cities and many towns have lost their dark night-time sky is Light Pollution. Light Pollution is simply the result of man-made light that has been wasted by shining up into the sky rather than being aimed down on the ground where we need it. Any street, building, or security light that is aimed up, above horizontal, is almost certainly wasting light and adding to light pollution. Exterior lights should point down towards the paths and roadways which we need to see when we are out at night. This wasted light causes Sky-Glow and Glare which ironically can make it harder to see as eyes attempt to adjust between over-bright areas and darker surroundings. You may have neighbors who have so over-lit the exterior of their home that their lights shine into your own windows. This is called Light Trespass and impacts our ability to get a good nights sleep.
The first step you can take is to check the exterior light fixtures on your home. Make sure that each fixture does not project light above a horizontal line marked from the lowest point of the fixture. If some of your lights shine up then re-aim them below horizontal or install a light shield which better focuses the light where it is needed. Security lights should be put on a motion sensor which enhances the 'Surprise!' security factor and also reduces wasted electricity. Outdoor path lighting can be done with solar-powered landscape lights which don't require extensive trenching for wiring and don't add to your electrical bill. Visit your local Hardware or Lighting store or one of the Vendors listed below for more ideas. Read the Night Sky Friendly Lighting Guide for more ideas and information on how to light your home, not the sky above.
If you want to do more to protect the dark night sky in your home town you can investigate whether your municipality has a law to protect the night sky. Thanks to the hard work of the New Mexico Heritage Preservation Alliance our state has the Night Sky Protection Act. This law was enacted in 1999 and exists to 'preserve and enhance the state’s dark sky while promoting safety, conserving energy and preserving the environment for astronomy'. I would add that a dark night sky can be appreciated by anyone whether they've taken an astronomy class or not. While this act is not yet thoroughly enforced, it is a step in the right direction.
While the idea of wasting light is a bit elusive, installing energy-efficient bulbs (compare the Lumen/Watt ratio) that shine when and where needed has a tangible benefit in lowering your electrical bills. So, using better lighting not only lowers your electrical bill it results in less light pollution and CO2 pollution from power plants. If you have a better example of a Win-Win solution, please let us know.
More Reading:
Night Sky Friendly Lighting Guide
New Mexico Heritage Preservation Alliance
