RAMADAN 1420: THE LONGEST FOR 300 YEARS

ATTEMPTED CRESCENT-SIGHTING, DECEMBER 8th 1999

PLACE . . . . . . . . TIME (UT) . . . . . . .MOON - SUN

UAE . . . . . . . . . . . . 13.57 . . . . . . . . . . . . . 6·6º
25N 55E

LEBANON . . . . . . .14.55½. . . . . . . . . . . . 6·7º
34N 36E

MOROCCO . . . . . . 17.57½. . . . . . . . . . . .7·8º
31N 8W

EAST USA . . . . . . . .21.49 . . . . . . . . . . . . .8·1º
42N 72W

WEST USA . . . . . . . 25.06. . . . . . . . . . . . . 9·3º
40N 120 W . . . . . (1.06 am on 9th)

JAMAICA . . . . . . . . 22.56. . . . . . . . . . . . .10·2º
18N 77W

Times are chosen so that the centre of the sun is six degrees below the horizon, ignoring refraction. (That is defined as the "end of civil twilight"). The "moon - sun" separation at that particular instant is then calculated in degrees from the centre of the sun up to the base of the crescent moon, again ignoring refraction - but allowing for topocentric parallax.
 
 

GULF CRESCENT-SPOTTERS WILL FAST FROM THE 10th

There is a very small chance that the crescent will be seen on 8th December 1999 from the west of the USA - perhaps from the mountains - if the air is extremely clear. However, reports from that area cannot really be transmitted to the UAE in time for fasting to commence on the 9th.

Although there will be more moon-sun vertical separation for viewers in the Caribbean, marginal atmospheric visibility there may well prevent successful identification. Also, as far as I know, there is no telephone contact between the UAE and crescent-observers in the Caribbean.

The Saudi Arabian calendar shows Ramadan commencing on the morning of 9th December (after 30 days of Sha'ban) - so this date will probably be retained for that country and for most other members of the GCC (thereby disagreeing with strict crescent-visibility criteria). For an explanation of a decision-system sometimes adopted by the Saudis in the past, see url http://www.world-federation.org/moonsighting/saudi_date_system.htm /. New Moon will actually be born at 22.32 UT on the 7th, so if they adopt that same system again this year, then their Ramadan will be declared even earlier - for the morning of the 8th. (Here, I must emphasise that it is not my prerogative to judge which method is right or wrong. Any process will work as long as its criteria are clearly defined).
 
 

A SLOW-MOVING MOON

In its elliptical orbit, the moon reaches apogee (maximum distance from Earth) on December 8th 1999 at 11.00 UT. This particular apogee (406,624km) also happens to be an above average one. That means that the moon will be migrating comparatively slowly, which helps to explain why there is not all that much difference between its height at dusk in the UAE and in Morocco on the 8th. (Remember too that the sun-moon line becomes less steep as latitude increases - and its departure from the vertical, adversely affects the topocentric altitude of the moon).

During this particular Ramadan (1420), the "lunation" (time taken for the moon to complete one circuit) will be 29 days 19.7 hours - which is significantly longer than the average value of 29 days 12.73 hours. In fact, this happens to be the longest Ramadan lunation for over 300 years. In order to find another one to equal it, we need to go back to Ramadan 1083 - which started with the New Moon of 19th December 1672 (Gregorian date).

This slow circuit means that even if the beginning of Ramadan 1420 is delayed till the evening of 9th December (i.e. the morning of the 10th), then Middle Eastern crescent-spotters will still need to wait a full 30 days more before seeing the Eid crescent.
 
 

ATTEMPTED CRESCENT-SIGHTING, JANUARY 7th

PLACE . . . . . . . . . TIME (UT) . . . . . .MOON - SUN

UAE . . . . . . . . . . . . 14.10½. . . . . . . . . . . 7·7º
25N 55E

MOROCCO . . . . . . 18.12 . . . . . . . . . . . . 9º
31N 8W

EAST USA . . . . . . . 22.04 . . . . . . . . . . . . 9·4º
42N 72W

WEST USA . . . . . . .25.21 . . . . . . . . . . . .10·8º
40N 120W . . . . . (1.21 am on 8th)
 
 

David McNaughton:

E-mail: DLMcN@yahoo.com



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