Expert: Tom Whiting - 11/15/2004

Question
Dear Tom Whiting   

I was wondering if it was scientficly possible to see the crescent of the moon with the naked eye on the night of Nov 12th 2004, and is there scietnfic resources I can refer to that proves this information. Since the showing of the crescent shows the start of the new Isalmic Month and there has been huge controversy on when the month should have been offically ended.

Thank you for any help

Answer
Hi Moe....
From Where?  And which date...November 12 in Greenwich
England,  Christchurch, New Zealand?  Or North Pole?

And which crescent moon?  Old morning crescent just ahead
of the sun, or young evening crescent right after sunset?

I'll assume you mean young evening crescent right after
sunset as I think most Eastern Religions follow that rule,
but I'm not 100% certain of that....

Ok, I went to my Sky Globe computer program and it shows that New Zealanders could have actually seen an old  crescent moon rising just before sunrise on their Nov 12, but it would have been a very difficult observation, as the moon was only about  21 hours from new phase, which occured at 1425 GMT, or 9:25 am EST for the USA east coast.  So moonrise for New Zealanders was only about 30, 35 minutes before their sunrise, so it would have been a very difficult observation for them....but it could have been an easy
binocular observation....but I'm talking about an old crescent in the Eastern sky, not the evening young moon crescent.

Now the moon was new at 2:25 pm over London, England,
GMT, so even from the International Date line, you only had about 15 or 16 hours until sunset...right on the limit for naked eye visibility and ONLY if the moon was on a fast upward rise
on the ecliptic, but to the contrary, the sun/moon are currently down on the southern, flat part of the ecliptic in the
Scorpius region, , so the moon does NOT move upwards, away from the sun very rapidly, IN FACT, it does so very slowly right now, in November and December, because the
ecliptic is relatively flat down in Sagittarius and Scorpius,
as you probably know.

For the young evening sky crescent, I punched in
Honolulu, Hawaii in my Skyglobe program, (that's as far
west that I can get on that program) and I find that
the young evening crescent moon was only 9 degrees
from the sun, setting about 20 minutes after moonset,
and this would be considered an impossible viewing,
even with binoculars....as I believe the naked-eye record is a
15 or 16 hour evening crescent moon, under perfect conditions, and Hawaiians would have been viewing only a 12 or 13 hour crescent....considered impossible, except with a telescope or binoculars, and I believe that is "disqualifing" for the calendar problem.

I also use Guy Ottewell's Astronomical Calendar 2004
(See Sky Publishing Corp. for a copy of the current year)
for my Old Moon/Young Moon sightings, as he goes  into
it in depth on pages 34 and 35 in every yearly issue, because
astronomers enjoy trying to spot the very old/young
crescent moons, just for the sport of it.

So the bottom line is.....I don't know what date the "experts"
picked for the beginning of the new Islamic Month,
but I would have discounted the 12th and picked the
13th of November as the first sighting of the young evening
crescent moon from anywhere on the Earth's surface.
Because I think even on the International Date line, even at the last second, sunset of November 12th, the moon would still not have moved far enough from the sun to be visible to the naked-eye, for your calendar event.

So, no, sorry.....your scientific resources would show that the
13th of November would be the proper date, as the
evening crescent had not moved far enough from the sun
to be a naked-eye viewing at any time on November 12,
2004... even at the last moment at the International Date
Line out in the middle of the Pacific Ocean.

You can check all this out for yourself, using any
astronomical computer program, as I just did....only problem
is that I can't punch in the International Date Line,...I can
only get as far west as Honolulu.

Hope all this helps,
and clears up the controversy,
but I'd be curious as to what actual date the "experts"
picked....but not knowing, I would have picked Nov. 13
as the beginning of a new month.
Clear Skies,
Tom Whiting
Erie, PA  USA