Astronomy Picture of the Day -- Jupiter and Venus from Earth

NASA ^ | August 17, 2014 | (see photo credit)

[messierhunter]

I just showed you that the moon being “upside down” is normal field rotation, it’s not new, and it’s completely predictable using the calculations I shared with you. I’ve been doing astrophotography for 14 years and I have yet to see the moon “out of place” or “rotated oddly” compared to where it should be. And yes, I can calculate all that myself:
http://dropcanvas.com/0hn26
“A lot of people” are wrong, I’ve measured it for myself and in cases where people have posted the time and location of their observations they claim show a “tilted” moon I’ve been able to show that it was normal. For example:
http://dropcanvas.com/7721m
http://dropcanvas.com/l0l53
Hell, I even got L.A. Marzulli himself to admit he was wrong about this.
http://dropcanvas.com/xsi93/1
When was the last time I looked at the moon? This morning.

[mountainlion]

So when will the man in the moon be right side up again? I have watched the moon since I was a kid and never saw it turn upside down before.

[messierhunter]

Then you clearly weren’t paying close attention to how the moon moves; this isn’t new. I just showed you a couple example photos from the 60’s and I have more old examples if you want them. As a rule of thumb, it’s “upright” when it’s at the meridian. You can use my spreadsheet and see for yourself how many degrees from vertical the moon should appear to be at any given time and location.
http://dropcanvas.com/0hn26

[mountainlion]

My latitude and longitude stay the same so how can the moon turn upside down. If I went to the southern hemisphere I under stand that the moon would change in prospective. How can Tycho go form the southern hemisphere of the moon to the northern hemisphere while in the same latitude and longitude. Don’t give me your references and tell me in your own words why the moon turned upside down. Then maybe when you get your nose out of your book we can come to a discussion.

[mountainlion]

One theory was that a massive object went through the solar system and caused the moon’s axis to rotate 135 degrees. The sun has flipped it poles recently also. The axis of the earth has moved and the magnetic north pole has moved so far that some airstrips have had to be renumbered because their compass headings have changed so much.

[messierhunter]

It has nothing to do with you changing location (or not changing location), it's field rotation, it happens from all non-polar aligned perspectives. In simple terms you're viewing the sky from the side of a rotating sphere and as a consequence the moon will appear to rotate to rotate up to 180 degrees a day relative to your local horizon. It does not mean the moon itself is tilted in some strange way, nor does it mean that the earth tilted in some strange way. See for yourself:
https://www.youtube.com/watch?v=-44HMPchDJ0

Had earth "tilted" in some strange way, my polar aligned telescope would not have worked this morning, but it worked just fine and recorded this long exposure (35 minutes of light) of comet Jacques next to the soul nebula without any field rotation (which would occur and cause a circular motion blur of the picture if the mount were misaligned because the earth had tilted).

My spreadsheet calculates the field rotation of the moon, it's perfectly normal and predictable. Don't give you my references? I created that spreadsheet myself. Do explain how it manages to work if this is abnormal? I don't know if you realize this, but it wouldn't even be possible for me to create such a thing (successfully) unless I knew what I was talking about.

[mountainlion]

Search finally came up with field rotation. We are talking about two different things. The formation Thycho was in the southern hemisphere of the moon and now is in the northern.

THE MOON IS UPSIDE DOWN!

[headsonpikes]

“THE MOON IS UPSIDE DOWN!”

I blame Global Warming.

[mountainlion]

I blame Global Warming.

I knew Al Gore had something to do with it.

[messierhunter]

The moon is not upside down, it rotates up to 180 degrees a day due to field rotation. The moon’s orientation is exactly what it should be. I’ve calculated and measured it for myself. Feel free to use my spreadsheet to see for yourself. For example:
http://imageshack.us/a/img46/1587/gjmv.jpg
Given the time and location of that image, here is the output:
Lunar Coordinates
Apparent Right Ascension at Equinox of date
Hours 9
Minutes 2
Seconds 39.33

Apparent Declination at Equinox of date
Degrees 11
Minutes 14
Seconds 42.73

Altitude (degrees) 1.53
Azimuth (degrees, 0 North) 77.93

Lunar Phase
Phase (percent full) 65.56%

Orientation of Illuminated Portion Relative to Horizon (degrees from vertical) 80.49
Illuminated limb facing towards the horizon

So if we rotate the image by 80.49 degrees, it should return the moon to an apparent “vertical” orientation, and indeed that is exactly the case:
http://imageshack.us/a/img202/8657/fqfv.jpg

[mountainlion]

So next full moon rise I am going to take a picture of the moon and compare it with previous pictures I have taken form the same deck. Are you saying it should be exactly the same as the historical picture?

[mountainlion]

So next full moon rise I am going to take a picture of the moon and compare it with previous pictures I have taken form the same deck. Are you saying it should be exactly the same as the historical picture?

[messierhunter]

No, why would a photo taken at an arbitrary time be in the same orientation as a photo taken at a different arbitrary time? You don’t understand how field rotation works, the exact time is a factor. How about I take a photo of the moon tomorrow morning (weather permitting) and show you that the orientation is normal even though it looks “tilted” from an altitude azimuth perspective?

[messierhunter]

Here’s my photo of the moon this morning taken at about 8:44 UT using a Canon XTi, a 300mm lens, and a tripod. At that time and my location here is the output from my spreadsheet (http://dropcanvas.com/0hn26 ):
Lunar Coordinates
Apparent Right Ascension at Equinox of date
Hours 6
Minutes 3
Seconds 16.16

Apparent Declination at Equinox of date
Degrees 18
Minutes 20
Seconds 25.58

Altitude (degrees) 22.35
Azimuth (degrees, 0 North) 80.21

Lunar Phase
Phase (percent full) 22.97%

Orientation of Illuminated Portion Relative to Horizon (degrees from vertical) 65.68 Illuminated limb facing towards the horizon

So, rotating this image 65.68 degrees should return the moon to an apparent “vertical” orientation. I rotated it in gimp by that amount and here is the resulting image:
http://h.dropcanvas.com/pb9au/530derotated.JPG
There you go, the lunar terminator and the lunar features (Aristarchus and Kepler crater are both visible in this image) are returned to a “vertical” orientation. The moon’s orientation is exactly what it should be according to my calculations.

[messierhunter]

Here’s the photo before I rotated it according to my calculations to return it to a vertical orientation:
http://h.dropcanvas.com/pb9au/530.JPG
It looks “tilted” but that’s how it should look from an altitude-azimuth perspective. Plugging in my location and time into my spreadsheet yields a result of 65.68 degrees from vertical and de-rotating the moon by that amount returns it to a “vertical” orientation as expected.
http://h.dropcanvas.com/pb9au/530derotated.JPG

[mountainlion]

http://129.164.179.22/apod/ap140907.html

Here is on that is upside down.

[messierhunter]

Yes, from Mount Victoria Lookout in Wellington, New Zealand. That’s in the southern hemisphere. The moon will look “upside down” from the southern hemisphere. The moon’s apparent orientation depends upon your location on earth.