Hobbies And Interests
Outdoor Lighting Pollution
Evaluate neighborhood light pollution by observing the lighting in the area or street near your house. Make a diagram depicting buildings and light fixtures, and label types of lighting, including street lights, exterior and interior house lights, and landscape lights. Note which lights point up- or downward, which are hooded lamps that only aim light downward, and the type of light bulbs being used. Mercury lamps put out a cold, white light; sodium lamps create a soft pink or yellow light; and incandescent light bulbs give an out off-white light. Lights pointing upward and un-hooded lamps contribute to light pollution. Rate the glare of each light fixture from one (no glare) to five (high glare). This will help you determine the best place to view stars in your neighborhood.
Determining Sky Darkness
Using a toilet paper roll, test sky darkness in four to five areas of town, from an area perceived to be the brightest to an area perceived to be the darkest. Hold the roll up to one eye and look up, count as many stars as possible. Take note of how many stars you counted in each location as well as the brightness of the stars from one (very bright) to five (dim). Compare the data between locations. Determine if light pollution decreases star viewing more in one area of town than another, which areas are worse for viewing, and which areas are better?
Light Pollution Atlas
Check out the World Light Pollution Atlas at Lightpollution.it. (See Resource 5) This site gives satellite imagery and color coded mapping to determine the light pollution and it's intensity for any part of the world. Compare different parts of the state, country and world to determine where pockets of light pollution are worse and where it is barely an issue. Also explore the Clear Sky Chart at Cleardarksky.com which gives astronomers times and dates when the least amount of obstruction will occur from full moon, fog and light reflecting clouds in a particular area. (See Resource 2) Use this in conjunction with light pollution data to determine the best places to view stars.
Measuring Sky Glow
On a night with no moon, travel to at least four or five locations with varied lighting, starting downtown and moving outward. Test light pollution with a photographic light meter or an astronomers Sky Quality Meter (SQM). In a notebook, record the location, description of area lighting, approximate star counts for each location, and readings from the light meter or SQM. Use light meter readings to determine the amount of light in each location and draw conclusions about how light pollution affects star viewing. With an SQM, determine how higher and lower readings correlate to the number of stars visible, brightness of visible stars, and light pollution. As an adjunct, take digital photographs of the sky at each location to complement the meter readings and personal observations.