Science Buddies: "Ask an Expert"

Hello! A few weeks ago my son's 3rd grade teacher asked the class to pick science fair project. No parameters were given. At the time he chose to study the effects of light pollution on star gazing. Our planned experiment was to study 3-4 local locations with in 10 miles of one another and with in a 90 minute time frame on 2 separate nights that were equal in temperature and cloud cover. Today she sent home parameters that now include performing a controlled experiment. I am having trouble figuring out how to create a controlled experiment with this project. I am assuming that the variable would be the change in venue but am having difficulty determining how to have a controlled group. Would it be the night sky being viewed on similar nights and time? Any help would be appreciated ASAP as this portion is due tomorrow! Thank you!

tubbscynthia1 - Here are some starting points for your experiment. There is a Science Buddies project that deals with measuring 'skyglow' and the effects it has on stellar observation. You can find it at this link. Read through the experiment and procedures for a better understanding.

https://www.sciencebuddies.org/science- ... p022.shtml

Also, just taking the subject you used - Studying the effects of light pollution on star gazing - and doing a search on the internet, you find numerous articles on the phenomena. I think with a little digging you will better understand how to create your experiment.

Rick Marz