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Position of Moon on Cumulus
Posted: Sat 29 Oct 2011 1:18 am
by Zebra400
Is there any reason why the view of the moon appears to be the wrong way around. I see the moon is curerently a waxing crescent, which suggests that viewable part of the moon should be on the earth's eastern side. However, Cumulus shows it on the left hand side.
Is there a reason for this?
Laurie
Re: Position of Moon on Cumulus
Posted: Sat 29 Oct 2011 2:10 am
by MickinMoulden
Please put your approximate location into your profile
Please supply your coordinates as put into Cumulus. This may be your problem. With these two pieces of information we can help.
Re: Position of Moon on Cumulus
Posted: Sat 29 Oct 2011 2:12 am
by beteljuice
Because your're wrong
Current Moon for general Northern hemisphere is
You don't give your location, but if the Moon is the 'wrong way round' it is usually because you have not correctly entered your N/S latitude in Cumulus set-up.
Re: Position of Moon on Cumulus
Posted: Sat 29 Oct 2011 3:27 am
by Zebra400
I think there is a bug in the program. My location is in Australia, so my lat & long are S & E in my home location. As you guys are in the northern hemisphere, I decided to change my location from S & E to N & E. Hey presto, the moon appears correctly.
Now, I have to ask the question, why does the program change the way the moon faces depending on your hemisphere location. Surely the waxing crescent is on the east side (right side) no matter which hemishpere you live in.
For me downunder, I think the program makes an incorrect assumption of our the moon appears in the southern sky.
Laurie
Re: Position of Moon on Cumulus
Posted: Sat 29 Oct 2011 3:47 am
by MickinMoulden
Beetlejuice is right.
In your Cumulus set up, just make sure it has N for north
Also, if you are in England (or there abouts), just after the sun sets, you will see Venus between the sun and the moon. Directly under Venus will be Mercury and on the ENE side will have Jupiter rising. This is the closest Jupiter gets these couple of days (until Dec 2012).
.....just found out something interesting, will post new topic.
Re: Position of Moon on Cumulus
Posted: Sat 29 Oct 2011 4:28 am
by beteljuice
For me downunder, I think the program makes an incorrect assumption of our the moon appears in the southern sky.
There are MANY Aus and NZ users who don't have a problem, and yes the Moon is transposed between hemispheres.
Have you done the 'double whammy' of declaring South and then entering a negative latitude ?
The figure entered should only be positive.
Re: Position of Moon on Cumulus
Posted: Sat 29 Oct 2011 5:10 am
by MickinMoulden
Zebra400 wrote:I think there is a bug in the program. My location is in Australia, so my lat & long are S & E in my home location. As you guys are in the northern hemisphere, I decided to change my location from S & E to N & E. Hey presto, the moon appears correctly.
Now, I have to ask the question, why does the program change the way the moon faces depending on your hemisphere location. Surely the waxing crescent is on the east side (right side) no matter which hemishpere you live in.
For me downunder, I think the program makes an incorrect assumption of our the moon appears in the southern sky.
Laurie
When you are in the Northern Hemisphere, the moon looks ofset to the left, which show the reflection on the right side of the moon. As you move from North to South the reflection rotates around from the right, underneath, then to the left. As for me, 12 degree's south, I get a big smiley face

. I have a programme I have found that you can put coordinates in and view the planets, moon and stars (constallations) from anywhere in the world at anytime, measure distances, view the solar system with Earth or any other planet as the centre location or zoom in and out of the whole solar system, spin it etc. It's fantastic. Would you like to know when we are closest to our closest planet? When the planets will align?
If your interested in seeing the solar system to scale, not by planet size (which is common), but by distance as well (an amazing feat you'll discover), then you can visit my Google maps page here:
http://maps.google.com.au/maps/ms?msid= ... 9,0.076818.
Just think of this when you visit, Earth, at a scale of 1 billion to 1, is under 12.8mm in diameter.
Re: Position of Moon on Cumulus
Posted: Sun 30 Oct 2011 12:10 am
by beteljuice
Are we to assume:
- The coordinates were correctly entered.
- The Moon was being shown in it's correct orientation.
- Zebra400 doesn't look up at The Moon

Re: Position of Moon on Cumulus
Posted: Mon 31 Oct 2011 8:04 am
by JennyLeez
I decided to change my location from S & E to N & E. Hey presto, the moon appears correctly.
Well that be weird. If I do this the moon swings around and faces the incorrect way.
As above have said, make sure lat and Long are correct with no negative sign.
Should be S and E and all should be fine.
It is not the program it is something you have set incorrect.
Check you have the time zone correct on your PC plus the time am or pm.
Maybe set on Greenland is not helping..... lol just joking.
Something is screwing it for sure.
c) Zebra400 doesn't look up at The Moon

Yep I will go for C.
Cheers
Re: Position of Moon on Cumulus
Posted: Sat 20 Apr 2013 1:05 am
by chook
3 years latter (from the last post on this) Ive Googled, read these forums and I do believe Laurie is onto something.
Looking at his site, it still show's the moon the wrong way round.
.. and I'm having the same issue. (Unless I stand upside down)
In the Latitude [deg] section us Southerners can't insert an -ve number. Cumulus won't allow it.
Changing the Latitude from N to S Fixes the Moon Problem - BUT -
The day length is now screwed.. Instead of the days getting shorter this time of year they aren't.
Re: Position of Moon on Cumulus
Posted: Sat 20 Apr 2013 9:31 am
by steve
Please could you attach a screenshot of your station settings screen (or at least the 'location' panel), and copy and paste the latitude and longitude lines from cumulus.ini, e.g.
Latitude=59.2425
Longitude=-2.58777777777778
Re: Position of Moon on Cumulus
Posted: Sat 20 Apr 2013 12:40 pm
by BCJKiwi
In New Zealand, never had (and stil don't) have a problem - once that is that I put Deg Min Sec & S and E in the settings screen.
The .ini file entry I never touched but it was created by the original setup and has both decimal degrees and Deg,Min,Sec entries.
Re: Position of Moon on Cumulus
Posted: Sun 21 Apr 2013 9:02 am
by MickinMoulden
chook wrote:3 years latter (from the last post on this) Ive Googled, read these forums and I do believe Laurie is onto something.
Looking at his site, it still show's the moon the wrong way round.
.. and I'm having the same issue. (Unless I stand upside down)
In the Latitude [deg] section us Southerners can't insert an -ve number. Cumulus won't allow it.
Changing the Latitude from N to S Fixes the Moon Problem - BUT -
The day length is now screwed.. Instead of the days getting shorter this time of year they aren't.
"Changing the Lat from N to S" is not fixing the problem, that's what it is meant to be, which is different to what Laurie is saying, he is saying he has to change from S to N to fix the moon picture when all three of us are in the southern hemisphere. To be clear, I have put in correct co-ords of S and E and the moon appears correctly (waxing to the right with a 10 day old moon at 77% illumination) AND also showing that daylight is getting shorter (as it will until the Winter Solstice in June). So it may be the version you have of Cumulus (although I've never noticed a problem upgrading through the versions) and is your computer clock set to the correct month? And looking at Laurie's post I don't see a link to a website to check. Do you have one?
Re: Position of Moon on Cumulus
Posted: Sun 07 Jul 2013 2:45 pm
by Asidonense
For a person who lives in the UK the moon always appears in the southern sky. For a person who lives in New Zealand the moon always appears in the northern sky. But whether you live in the UK or in NZ the moon rises in the east and sets in the west.
In the UK a new moon is a thin crescent on the viewer's right of the moon, and the moon is to the left of the setting sun. In NZ the thin crescent is on the left side and the moon is to the right of the sun. In the UK the illuminated part of the moon increases to the left during the following days, while in NZ it increases to the right. In both places the moon appears farther behind the sun every night and at the full moon it is rising on the opposite (eastern) horizon as the sun is setting - more or less, but it depends on the time of year.
When you are in the tropics you do not look north or south to see the the sun or the moon, they pass overhead. This means that the new moon appears as a shallow bowl briefly visible in the western sky just above the horizon at sunset, which as many people know happens faster in the tropics than at higher northern or southern latitudes. In the following nights the moon increases in size from the bottom upwards. Not from the left nor from the right, upwards.
As luck would have it there is no moon at all tonight so I cannot check the image right now, but as I recall the image of the moon on my computer changes from right to left with the north pole of the moon always at the top. This representation works in the same way as a number of conjuring tricks - but that is not a topic for this forum.
Most members will know that the moon spins on its axis as does the Earth, Sun, other planets, etc, and that having been caught in Earth's gravitational field the moon continuously presents the same face to us.
So how accurate should the representation of the moon be? I suspect that most weather enthusiasts are not interested in the phases but that those who are want accurate details. Well, the moon also has a north and south pole because as we know it rotates, though only slowly compared with Earth. Seen from UK the north pole of the moon is usually more or less at the top, but seen from NZ the north pole of the moon is at the bottom. In the tropics a rising full moon has its north pole on your left, not at the top, and its south pole at the right
I confess that I have not experimented by telling Cumulus that I now live in Dunedin, as I once used to, or in Honolulu, as I once used to, to see what the effect on the moon phase will be. But I suspect that the code for presenting the phase of the moon takes no account of the location of the observer beyond whether he/she is northern or southern hemisphere.
I offer two solutions..., er..., suggestions:
1. Orient the poles of the image of the moon to match those of the latitude of the weather station and its observer.
2 (perhaps a lot easier). Use a plain white disk to represent the moon and let everyone work out for him/herself what this represents in the sky above him/her.
Re: Position of Moon on Cumulus
Posted: Sun 07 Jul 2013 3:13 pm
by mcrossley
Option 1 is non-trivial, the apparent orientation of the Moon's poles varies as the Moon crosses the sky. This ignores libration and topocentric effects which are also visible to the naked eye observer.