Yesterday evening’s nearly-full Moon photographed at intervals 3 hours and 57 minutes apart:
Above, at 7:34 PM CDT 10-9-11 (00:34 UTC 10-10-11).
Below, at 11:31 PM CDT 10-9-11 (4:31 UTC 10-10-11).
As usual, 8″ reflector telescope, 25mm eyepiece, LG VX8360 cell phone camera. Click for larger view. Considering that I use the inexact method of aiming my cell phone camera by hand into the telescope eyepiece, I tried my best to approximate the actual orientation of the Moon with respect to my local horizon. I didn’t use to try so hard, but I’ve become aware that with the concern many have these days about alleged changes in the Moon’s orbit, the Moon’s orientation in the sky has become an issue, so I’m now trying my best to document what’s actually observed. What you’re seeing in these pictures is nothing more than field rotation. Since I’m at roughly 46 degrees North latitude, the Moon and other celestial objects rise upwards and to the right at a slope of roughly 44 degrees (44+46=90), which means that when it’s in the east it looks rotated counterclockwise, as in the first photo, when the Moon was in the East-Southeastern sky. In the second picture the Moon was almost directly South, so field rotation evened out. The Moon looks at that point like it’s rotated slightly clockwise, because it was “climbing” toward the northernmost part of its monthly path through the sky, which it will reach on 10-16-11. That’s all that’s happening.
Lots of people continue to stop by my site looking for information about the Moon’s orbit and the following recent paper by professional astronomer Dr. Lorenzo Iorio:
On the anomalous secular increase of the eccentricity of the orbit of the Moon
Since I’ve even recently been cited as a source for a lay-level explanation of Dr. Iorio’s paper (and I’m honored to have been cited), I feel an obligation to write with greater detail and clarity on the subject. I have nothing to offer but careful observations, careful reading, careful listening, and careful thought, but if that interests you, watch my site within the next two weeks for a detailed post on Dr. Iorio’s paper.
[…] As promised, I shall offer a few notes in hopes of clarifying for the layperson what is said, and what is not said, in this paper by professional astronomer Dr. Lorenzo Iorio: […]
I looked at the eastern sky moon in Columbia SC USA at 11pm on 10/19/13; it appeared exacty as per your TOP photo…the next morning ; however, I rose at 7 am and it DID NOT APPEAR as per your BOTTOM photo – ! It appewred to have rotated SEVERELY to the RIGHT by approx. 90 DEGREES. I have photos of the moon – with good detail – between tall pines, so one can see the extreme perturbation anomaly. I am not a conspiracy nut. I also admit the possibility of error. I just want to know why there is such a discrepancy in the aspect. Pick up my video at https://www.youtube.com/watch?v=Et_GU7nn10Y.
Thanks for stopping by, and I did look at your video, which is beautiful! I like the gentle music with it as well.
A couple of things to keep in mind about your observation. First of all, during the eight hours between 11 PM and 7 AM the next morning, the Earth made 120 degrees of its daily rotation on its axis, and this alone is the largest factor in the change in the Moon’s apparent orientation. It isn’t that the Moon itself changed, but that Columbia, SC and its inhabitants are viewing the Moon from a very different angle 8 hours later.
Secondly, at Columbia, SC you are 34 degrees north of the Equator, which means (1) that when you look northward on a clear night you see the star Polaris roughly 34 degrees above the horizon, and (2) the Sun, Moon, and other objects therefore rise in the east “uphill to the right” at a steep angle of 66 degrees, and later set “downhill to the right” at that same angle of 66 degrees. Therefore, in your location, if you observe the Moon from moonrise to moonset, you’ll actually see an apparent rotation of the Moon’s disk of 132 degrees to the right, every time it appears. When the Moon rises it will always appear tilted to the left, and it will always appear tilted to the right when it sets. But the one doing the real “tilting” is you! (and me)
Picture it this way: imagine that you are laying down in a recliner, carefully set to lean back 66 degrees in your backyard in Columbia. Face your recliner directly south, so that the top of your head points toward Polaris, the north star. Then teach yourself to think that “up” isn’t towards the zenith of the sky, but rather toward the north star. You look east (left) at moonrise, and since you’re already pre-tilted, the Moon doesn’t go “up” from your point of view, but simply “across” from left to right. And as it goes across the sky, it won’t appear to “rotate” at all when viewed in this manner, but will look “upright” all the way across.
I hope that helps. It really helps a lot to remember that there’s no real “up” or “down” in space, and that when we view the heavens from the surface of our rotating Earth, the point we call “up” is in a different direction every moment.