Predicting Weather By The Moon - Xavier University Libraries

Weather By The Moon
ground stars. It moves about 13 degrees (26 times its apparent
diameter) in 24 hours (slightly greater than its own
diameter) in one hour. This rapid motion has given it a
unique role in the history of astronomy. For thousands of
years it has been used as the basis of calendars. Isaac Newton
deployed crucial information from the Moon’s motion
around the Earth for the law of gravity.
Almost everyone has noted that we see the same face
of the Moon all of the time. It’s the ‘Man in the Moon’ that
children are enthralled by. One thing this shows us is that
the Moon turns exactly once on its axis each time that it
goes around the Earth. The pull of the Earth over millions
of years has caused the Moon, which once rotated by itself,
to now be relatively orbit-free, in what we see as a
face-to-face dance of the Earth and Moon.
It drifts eastward with respect to the background stars
(or it lags behind the stars). It returns to the same position
with respect to the background stars every 27.323 days.
Half a billion years ago, the Moon lay closer to the
Earth in its orbit and it has been moving away into the beyond
of outer space ever since, at the rate of about an inch
per year. As the Moon recedes, our month increases by
about a second every 4,000 years. We know from fossil
records of rock formation that 350 million years ago the
month was a day and a half shorter, making for closer to
13 months in the year rather than 12.
There seems to be general agreement that at one stage,
thousands of millions of years ago, the Moon was closer
to us than it is today; perhaps as little as 12,000 miles. If
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