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Why Does the Moon Appear Larger at Some Times? *

Time Required Very Long (1+ months)
*Note: This is an abbreviated Project Idea, without notes to start your background research, a specific list of materials, or a procedure for how to do the experiment. You can identify abbreviated Project Ideas by the asterisk at the end of the title. If you want a Project Idea with full instructions, please pick one without an asterisk.


Some claim the Moon appears larger when near the horizon. Make a series of observations of the Moon, measuring the Moon's angular diameter each time. You should also note the Moon's altitude above the horizon, and the Moon's phase. You should do background research on the lunar orbit to determine the necessary time period. Do you find predictable variations in the Moon's diameter? Can you relate this to the Moon's changing distance from Earth? From your data, try to determine when apogee and perigee occurred during your observations. Compare your calculated answer with published dates (Pierce, 2005). For another method of measuring the distance to the Moon, see How Far Away Is the Moon?

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Science Buddies Staff. "Why Does the Moon Appear Larger at Some Times?" Science Buddies. Science Buddies, 30 June 2014. Web. 25 Oct. 2014 <http://www.sciencebuddies.org/science-fair-projects/project_ideas/Astro_p030.shtml>

APA Style

Science Buddies Staff. (2014, June 30). Why Does the Moon Appear Larger at Some Times?. Retrieved October 25, 2014 from http://www.sciencebuddies.org/science-fair-projects/project_ideas/Astro_p030.shtml

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Last edit date: 2014-06-30


Pierce, J., 2004. "Ideas for Astronomy Science Fair Projects," Astronomy Program, Minnesota State University, Mankato [accessed December 01, 2011] http://mavdisk.mnsu.edu/jpierce/scifair.html.

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