Astronomy/Moon turns


QUESTION: This is probably a dumb question, but how often does the moon turn circularly from an earth perspective? In which the man in the moon appears to be flipping upside-down? When I was young he appeared perfectly verticle facial feature wise, but now he appears to be on a slant. :( lol.

ANSWER: Hello,

I suspect that the answer to your question is likely along the lines of one already addressed. See, e.g.

---------- FOLLOW-UP ----------

QUESTION: I was not refering to lunar phases and lighting. I am refering to a physical turn of the moon. Like if you drew a line from the center of the moon out to a particular crater and determined at what degree that crater is. It seems like in my lifetime the location of craters creating the "man in the moon" appear to be turned a bit to one side.


Actually, no. There's no evidence of which I'm aware of any such 'turning', apart from the motions associated with nutation in obliqity (delta eta), by which we see a little bit more of its far side- beyond its poles-  every now and then. Also - which craters are you defining as creating a 'man in the Moon'? (Too subjective a description for astronomical use).

Also, what instruments did you use to observe this change? Binoculars? Telescope?  To have a genuine assessment of changes such as you describe you can't go by naked eye estimates. At the very least you'd need to steadily observe the area in question with a small power (e.g. 30x) telescope, perhaps equipped with some kind of reference marker, e.g. cross hairs. Then, on making consistent observations over time, you can more reliably determine whether observed locations of craters are really changing (say with respect to your cross hair center, denoting an actual 'turning' effect)  or are more in the way of an optical illusion.

Hopefully, this will perhaps encourage you to do more detailed observations of this apparent phenomenon and then satisfy yourself with your own observations whether it is real or not.  


All Answers

Answers by Expert:

Ask Experts


Philip Stahl


I have more than forty years of experience in Astronomy, specifically solar and space physics. My specialties include the physics of solar flares, sunspots, including their effects on Earth and statistics pertaining to sunspot morphology and flare geo-effectiveness.


Astronomy: Worked at university observatory in college, doing astrographic measurements. Developed first ever astronomy curriculum for secondary schools in Caribbean. Gave workshops in astrophysics and astronomical measurements at Harry Bayley Observatory, Barbados. M.Phil. degree in Physics/Solar Physics and more than twenty years as researcher with discovery of SID flares. Developed of first ever consistent magnetic arcade model for solar flares incorporating energy dissipation and accumulation. Develop first ever loop solar flare model using double layers and incorporating cavity resonators.

American Astronomical Society (Solar Physics and Dynamical Astronomy divisions), American Mathematical Society, American Geophysical Union.

Solar Physics (journal), The Journal of the Royal Astronomical Society of Canada, The Proceedings of the Meudon Solar Flare Workshop (1986), The Proceedings of the Caribbean Physics Conference (1985). Books: 'Selected Analyses in Solar Flare Plasma Dynamics', 'Physics Notes for Advanced Level'. 'Astronomy and Astrophysics: Notes, Problems and Solutions'.

B.A. Astronomy, M. Phil. Physics

Awards and Honors
American Astronomical Society Studentship Award (1984), Barbados Government Award for Solar Research (1980), Barbados Astronomical Society Award for Service as Journal Editor (1977-91)

Past/Present Clients
Caribbean Examinations Council, Barbados Astronomical Society, Trinidad & Tobago Astronomical Society.

©2017 All rights reserved.