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Crescent moon positions

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snooper | 16:13 Tue 24th Jun 2008 | Science
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I desperately need to know the answer to the below question and am sure you brainboxes will have all the info.
I know virtually nothing about astronomy and have spent hours looking on the internet for the answer to my question, with no result - that I can understand anyway.

So here goes:
When a crescent moon rises (becomes visible) goes across the night sky and then sets in the course of one night, what would the moon look like? What I mean is in a stylised diagram would the moon's crescent points be away from or facing the earth when at rising, setting and halfway point?
If anyone understands my question and can answer it, in words of one syllable, or point me in the right direction internet wise I would be hugely grateful. (I would then be able to go and watch the delectable Nadal without feeling guilty)
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The apparent shape of the moon is not related to whether it is rising or setting but due to the moon's angle between us and the sun.

look at this:

http://www.afreshhorizon.co.uk/images/moon_pha ses.jpg

Now imagine the earth rotating (a day) the moon will appear to rise and set.

During that time the moon will look the same.

However over the period of about a month the moon circles the arth and different portions are illuminated giving you different shapes.

Simply speaking

A cresent moon is a cresent moon all night
And incidentally:

If you want to remember which way the moon faces (in the northern hemisphere) then use this mnemonic

C O D ( or even G O D )

If the O represents the FULL moon, then before it is full, the curve is on the left, and after it is full, the curve is on the right.

(Those in the southern hemisphere will see the moon the opposite way pound and will have to remember D O G instead.)
PS, What is Nadal, and what has it to do with the phases of the moon?
pound ?????????????????????????

*** Round *** of course - and the P isn't anywhere near the R on my keyboard, so what happened there is anybody's guess.

If the Moon is visible all night it is not a crescent, it is either or very nearly a full moon (or at least gibbous at extreme northern or southern latitudes). A full moon is opposite the Sun and so rises as the Sun sets and then at sets at sunrise. A crescent moon either sets within a few hours after sunset or rises within a few hours prior to sunrise.

By the way, crescent is a two syllable word (and syllable has three) . . . hardly fair!
Question Author
Thanks for your replies.

Unfortunately I am no further forward in solving my problem. I am trying to produce (for a design) a stylised diagram that would represent the passing of "one night". My idea was to have a crescent moon as opposed to full or nearly full, as that would look too much like a sun and therefore day time, that rose on the left passed through the zenith and set to the right. I now understand that due to phases of the moon that doesn't really happen, but I am sure it is a device I have seen used in cartoons to express a speedy moving from evening to the next morning.
Using C O D would I be right to simply have the C shape on the left another above and a third on the right, or does it appear to tilt, as it and we move, and come down in a D?
I hope you can understand the simplistic idea from which I am coming.
In the course of one night the moon must appear to rise and then set as daylight approaches - and must be expressed in a childlike diagram.
Here's hoping for more help, after all I don't really want to stand in the garden all night.
Thank you again.
Well firstly of course you won't necessarilly need to stand all night in the garden because sometimes the moon rises and sets during the day. I'm sure you'll have seen it.

Now that I understand that what you're after is a graphic representation of a night rather than a realistic display I have to ask "Does it matter?"

I'm sure that however you choose to illustrate it nobody's going to pick you up on it and even if they do you can say "Come on don't you know the moon doesn't even change phase during a single night!"


Nearly 8 years later but what the heck?

As I write, a crescent moon is setting in the west. The sun is below the horizon but the bright portion of the moon points towards it. Because the plane of the solar system (the ecliptic) is tilted, relative to the horizon, the lit part is from, roughly, the 1-o'clock to the 7-o'clock positions. The rest of the moon's face is lit by "earthshine" and is a pale grey, lighter than the sky's dark blue shade.

So the shape of a new moon is the *reverse* of "C", with the 'horns' of the crescent pointing at an angle to the left and slightly upward.

Winding back to the start of the day, the sun would have risen first, the moon some time behind it i.e always to the sun's left. Again, the lit portion of crescent respects the sun's position and the horns of the crescent would have angled left but downward. Overall, the brightness of the sun may have drowned out the light reflecting off the moon, for much of the day. If it fails to contrast adequately with the sky colour then you would struggle to perceive it against the glare from the sun.

The "C" shaped moon is the waning, old moon, which you'd only see if you were up before the dawn. Again, it is hard to spot against the sun's glare and it sets before the sun i.e. it is always to the sun's right.

So, for cartoon purposes, you can either: a
i) Use artistic licence, show a crescent rising, horns down, crossing the sky, all the while rotating clockwise, such that the horns are pointing left, at the zenith, then upwards as it sets or
ii) show the sunset, then have the cresent emerge from the increasing gloom but low above the horizon, then it sets but the rest of the passage of time would have to be portrayed by having the stars move and set, while preserving their patterns - which would be horribly complex to do by hand.

As above, it's a cartoon and nobody's going to be that fussed. In fact, the more kids discover that reality is unlike cartoons, the cleverer they feel and the more curiosity they have about why things are as they are.

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