Featuring Let There
Be Night and Night Vision.
Errant and excessive outdoor lighting detracts from the night.
Often dubbed light pollution, this wayward light is commonly seen as glare,
spillover (including light trespass), and sky glow.
Why does it matter? By implementing better lighting practices:
|-you save money and energy;
-you improve safety for motorists and
-you increase security and the sense of well-being;
|-you benefit animal habitats;
-you preserve the starry night;
-you improve the quality of life;
|-you lessen greenhouse gas emissions that
contribute to global warming.
Correcting the impact of light pollution is often just a matter of
awareness. You can help prevent outdoor lighting from impinging on the
night sky by aiming lights downward; by turning lights off when not in use; by
covering exposed light sources with full cut-off shields; by not over-lighting;
and by installing sky-friendly fixtures. Please take pride in preserving
our common heritage, for we are all stewards of the night.
Let There Be
Night program features two DVDs of resources that support dark skies. See
The International Dark-Sky Association
defines light pollution as "any adverse effect of artificial light
including sky glow, glare, light trespass, light clutter, decreased visibility
at night, and energy waste." While high-quality exterior lighting can
benefit society, below are some typical nightscapes around town. (See more
examples of both good and bad lighting.)
(See more examples of
good and bad, from around
There Be Night Program
There Be Night is a two-part program in which students first visit a
planetarium to experience three aspects of light pollution. They
decide whether to act to address the glare, sky glow, and light trespass,
and if so, how. Second, the students quantify the sky glow over the community both
through visual observations and with hand-held Sky Quality Meters.
Students in grades 3-8 participate in the hunt for stars in Orion as
part of the Globe at Night
program. In the classroom they interpret their data and discuss the trade-offs of lighting
technology and the social decisions related to outdoor lighting. Finally,
the citizen-scientists share their results with the community. As part of the 2009 International Year of
Astronomy, a team of students in the Penn Harris Madison school district
built a 3-D model of their results
out of 35,000 LEGO® blocks based on the
observations of 3,400 students. See www.lettherebenight.com
National Park Skies
In broad terms...
"For a typical unshielded light fixture, 50% of the light shines
upward. This is a direct waste and is the main cause of light
pollution...Light emitted horizontally tends to create glare, working
against the productive light. A shielded fixture eliminates the upward
light and minimizes glare, allowing a much smaller wattage bulb to be
used." Courtesy of the U.S. National Park Service.
Caveat: The total energy loss is much worse than it
appears. See Energy Chain.
In Light Pollution
Handbook, authors Kohei
Narisada and Duco Schreuder conclude that the greatest challenge
falls in the laps of educators. “A lack of awareness, rather than specific
resistance, is generally the biggest problem in controlling light pollution.”
The best means to improve the situation is education outreach, they assert, for the path to
darker skies is “more a matter of improving priorities, rather than of
inventing new tools.”