[HPforGrownups] Re: Full moon question for the folklorists

[Shaun Hately]

No: HPFGUIDX 97532

On 2 May 2004 at 16:07, scoutmom21113 wrote:

> Bookworm:
> According to the Farmer's Almanac, there are at least 7 daytime full 
> moons on 2003 and 2004. 

You're misreading the almanac - the times given are the moments of 
totality - the point where the moon is truly, absolutely 100% full. 
This has nothing to do with whether or not the moon is visible in 
daylight from a giving location.

> By my figuring, about 30% of the time the 
> moon is full during the daytime. And from my observations, the full 
> moon rises during the late morning and sets a little after midnight. 
> (Just my observations, and I'm late for work, so I can't check it 
> now.) 

Not on planet Earth, so unless you're a really long way away.

The phase of the moon is dependent on its entire face (from our 
point of view) being directly pointed at the sun. The only time 
this can occur is when we are on a direct line between the moon and 
the sun. When that occurs, the moon always rises near sunset, is at 
its peak near midnight, and sets near sunrise (for given values of 
'near').

This is absolute astronomical fact. Both the phase of the moon and 
the time of moonrise/moonset are completely and totally linked to 
the alignment of the sun, moon, and earth, and both match these 
patterns.
 
> July 13, 2003 - 2:21 pm
> September 10, 2003 - 11:36 am
> December 8, 2003 - 3:36 pm
> January 7, 2004	 - 10:40 am 
> May 4, 2004 - 	3:33 pm
> July 31, 2004 - 	1:05 pm
> December 26, 2004 - 10:06 am
> http://www.farmersalmanac.com/astronomy/fullmoons.html

Those times do not indicate the full moon is visible during 
daylight. Rather they indicate the moment of complete totality, 
when the moon may well be below the horizon - in fact, it will 
absolutely certainly be below the horizon for about half the 
planet.

The time the moon rises depends on your location.

Let's just look at one of the dates so we can see what is indicated 
here. January 7 2004 - 10:40am EST.

Because it's EST, we'll grab a US east coast location - New York. I 
could use any other location - I just already have its settings.

At that point, while the moon is full, it's *well* below the 
horizon - 20 degrees below the horizon in fact.

It won't rise until 4:36pm - 8 minutes before sunset.


Yours Without Wax, Dreadnought
Shaun Hately | www.alphalink.com.au/~drednort/thelab.html
(ISTJ)       | drednort at alphalink.com.au | ICQ: 6898200 
"You know the very powerful and the very stupid have one
thing in common. They don't alter their views to fit the 
facts. They alter the facts to fit the views. Which can be 
uncomfortable if you happen to be one of the facts that 
need altering." The Doctor - Doctor Who: The Face of Evil
Where am I: Frankston, Victoria, Australia