1. Determining the Light Pollution of the Arizona Skies Eighth Grade Gridley Middle School Students

2. Introduction In Tucson, Arizona, we experience light pollution in some of these ways:  Our neighbors porch light lights up my backyard  We can see the clouds in the night sky on a cloudy night  When riding in the car at night, we have to squint from the glare as we approach the street lights The presence of light pollution affects the way we are able to observe the night sky.

3. Method of Observation  Dates of Observations: April 5 th - April 9 th  Time of Observations: 15 minute time span between 8:00-9:00 PM  We observed the night sky looking for the constellation of Orion. Then we compared our view to a series of star maps which showed the varying degrees of how well we could see the stars.

4. Results Date5 April 056 April 057 April 058 April 05 9 April 0510 April 05 Ashley 4 3 Andrea 5 2None462 Ryan222 Michael M. 3 22 Bryce 4 4None44 Stacy3455 Jennifer 4 35 Michael C.None4 Josh 3 Anastasia 5 Results in blue were represented on the Tucson map.

5. Inferences It is interesting to see so much variation in people’s observations, especially since we all live relatively close to one another. When looking over the details people recorded, the neighborhoods had some significant differences. For example, on the evening of April 5 th, one student recorded a result of four and another of two. The student who recorded a four lives in a neighborhood where the nearest porch light was two houses away. The student who recorded a two lives in a neighborhood where every house has a porch light that cannot be turned off. This type of result supports the idea that outside lights contribute to light pollution.