I found the article “Earthshine, Moonshine, Albedos, Climate…” in the Astro-Notes column in the Sept. 2018 issue (p. 406) interesting and informative. I wish to comment on the author’s presentation of why eclipses do not happen more often. Agrawal writes “the plane of the Moon’s revolution is inclined at an angle of approximately 5° with the plane of the revolution of Earth around the Sun; that is why eclipses do not happen more often because during most months the Moon is ‘above’ or ‘below’ Earth.” This statement is correct but without a diagram may be confusing to students. The source of the confusion may lie in the fact that side views of the solar system and the Sun-Earth-Moon system are rare. What is typically found are diagrams similar to Fig. 2 and Fig. 3 in the article, which are top views. When making presentations that involve the solar system and/or...

AAPT members receive access to The Physics Teacher and the American Journal of Physics as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.