About Light Pollution Rappahannock Astronomy Club Presented by Scott Busby Member, Rappahannock Astronomy Club
Presentation Agenda Introduction to Light Pollution How many Stars Can You See? Our Atmosphere Sources and Effects of Light Pollution What Can We Do About it? Conclusion Image Showcase
What is Light Pollution? Urban light pollution and light trespass has a drastic effect on our environment and should be regulated through implementing strong lighting ordinances. It destroys our view of the night sky and directly contributes to a decrease in some animal and plant populations. It also has a marked detrimental effect on astronomic research.
How many Stars Can you See? The night sky at the Black Forest Star Party in Cherry Springs, PA. The night sky at Batsto, NJ. This is a moderately dark-sky site with some light pollution. The night sky at an suburban park in Voorhees, NJ.
Our Atmosphere The composition of the atmosphere is 79% nitrogen, 0% oxygen, and % other gases. These gases are the constituents of water vapor that forms clouds and it also combines with obscurants like dust and smoke. Carbon dioxide is also prevalent as a natural occurring gas or it is the result of pollution from human industrial activities and automobiles. These gases and pollutants when combined tend to filter out all but the brightest of stars visible to us from earth's surface and reflect lights from the ground.
The Incandescent light bulb Since the industrial revolution the amount of light pollution in the atmosphere has increased exponentially with the invention of the incandescent light bulb. Advances in electrical lighting technologies occurring during the latter 0th century have resulted in a remarkable increase in the illumination of our cities, businesses, and homes. These technologies like florescent tubes, halogen and halide fixtures, sodium and mercury based lighting and other types light our path through the night.
Effect on the Natural Environment "Light pollution s harmful effect on wildlife has been welldocumented. It disturbs the breeding cycles of animals, stunts the growth of certain flora and fauna, and in some animals, even affects the production of hormones regulating everything from fat storage to egg production."
Energy Consumption X 0 = kilowatt hour ( Kwhr = 000w) Number of hours/yr: 470 Lamp life: 000 hours X 4 bulbs operating cost $4.9 kwh / yr: 47 Carbon Dioxide emission: 58 pounds Sulphur Dioxide emissions: 7 pounds Nitrous Oxide emissions: 4 pounds Mercury released/yr: 4 ounces Coal used: 96 pounds Emission equivalent (same as driving): 475 miles Number of trees to null effects: Light pollution or the creation of it, causes another problem that needs addressing. Artificial lighting requires electricity that is produced by the consumption of fossil fuels. Burning of fossil fuels adds pollutants to the atmosphere by introducing particulates and greenhouse gases. This results in the increase of carbon dioxide which contributes to global warming.
Impact on Astronomical Research
Impact on Astronomical Research Without a telescope, your eyes can just barely see magnitude 6 stars. The distant planet Pluto is magnitude 4, so you definitely need a telescope to see it. The best telescopes on Earth can spot stars with magnitudes between 5 and 7. The Hubble Space Telescope can sometimes "see" magnitude 0 stars. Naked Eye Visible Number of stars brighter than magnitude Apparent magnitude Number of Stars 0 4 5 48 7 4 5 5,60 6 4,800 7 4,000 Spotsy Mall England Run Virginia Skies Belmont Obs. W of Blueridge
What can we do About Light Pollution? Several counties in the state of Virginia have already enacted lighting ordinances that restrict wasteful lighting. Most lighting ordinances identify the most bothersome types of lighting and limit them in numbers, maximum wattage output, spectrum, height above the ground, timed illumination and horizontal emission.
What can we do About Light Pollution? Hubbell SkyCap GE SkyGard Shield
Conclusion Hundreds of amateur Astronomy clubs have also instituted programs that increase public awareness and show how to reduce the overall impact of light pollution. As for your help, it is quite simple, reduce light pollution by following a few simple rules:
Conclusion Don t waste energy! Turn exterior lights off between the hours of 0pm and 5am. Reduce output of outdoor security lights and porch lights by using lower wattage bulbs. Shield outdoor flood lights so they illuminate the ground beneath them and not a large area around them. Put driveway flood lights on a timer or use motion sensor lights. Remove, turnoff, or shield pole mounted security lights.
Image Showcase - Moon
Image Showcase - Mars
Image Showcase - Saturn
Image Showcase - Jupiter
Image Showcase Deep space Objects