Measuring the apparent size of the Moon with a digital camera

Ellery, Adam & Hughes, Stephen (2012) Measuring the apparent size of the Moon with a digital camera. Physics Education.

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The Moon appears to be much larger closer to the horizon than when higher in the sky. This is called the ‘Moon Illusion’ since the observed size of the Moon is not actually larger when the Moon is just above the horizon. This article describes a technique for verifying that the observed size of the Moon in not larger on the horizon. The technique can be easily performed in a high school teaching environment. Moreover, the technique demonstrates the surprising fact that the observed size of the Moon is actually smaller on the horizon due to atmospheric refraction. For the purposes of this paper, several images of the moon were taken with the Moon close to the horizon and close to the zenith. Images were processed using a free program called ImageJ. The Moon was found to be 5.73 ±0.04% smaller in area on the horizon then at the zenith.

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ID Code: 53017
Item Type: Journal Article
Refereed: Yes
Keywords: Moon, illusion, digital, camera, ImageJ
DOI: 10.1088/0031-9120/47/5/616
Subjects: Australian and New Zealand Standard Research Classification > EDUCATION (130000) > OTHER EDUCATION (139900) > Education not elsewhere classified (139999)
Divisions: Current > Schools > School of Chemistry, Physics & Mechanical Engineering
Current > Schools > School of Mathematical Sciences
Current > QUT Faculties and Divisions > Science & Engineering Faculty
Copyright Owner: Copyright 2012 Physics Education
Deposited On: 27 Aug 2012 23:08
Last Modified: 25 Oct 2012 06:10

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