Question: I have
checked the dates of the New Moons at NASA, and have found that NONE of the "New
Moon" dates agree with WLC. Can you
please explain why there is this difference?
Answer: The perceived
discrepancy here is due to a misunderstanding of calendation terms. The "Astronomical New Moon" and
"New Moon Day" are not
synonymous.
(1) Astronomical
New Moon – The Astronomical New Moon is often referred to by astronomers
simply as the "New Moon" or as the "Conjunction." During the Astronomical New Moon, the moon’s
unilluminated side is facing the Earth. The moon is not visible (except during
a solar eclipse). (http://aa.usno.navy.mil/faq/docs/moon_phases.php)
(2) New Moon Day
– New Moon Day commences at the first dawn after
the "Astronomical New Moon [Conjunction]" has occurred. This means that the Astronomical New Moon and
New Moon Day will always be one calendar date apart for any specified area. For example: If the Astronomical New Moon
(Conjunction) occurred at 12 pm on December 2 in your area, then New Moon Day
would commence at dawn on December 3.
For more on this important topic, see New Moon
Day: The Dawn After Conjunction.
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