The moon: the light that rules the night
Our Moon. God created it. Man reached it. Poets have written about it. Find out
about some fascinating truths behind our great ‘lesser light’…
by Jonathan Sarfati
The moon—an object of wonder since the dawn of mankind. It lights up the night
sky like nothing else in the heavens, and appears as if it regularly changes shape.
As we shall see, it is well designed for life on Earth, while its origin baffles
evolutionists.
The moon’s origin
Although there are many different ideas on how and when the moon formed, no scientist
was there at the time. So we should rely on the witness of One who was there (cf.
Job 38:4), and who has revealed the truth in
Genesis 1:14–19:
‘14 And God said, Let there be lights in the firmament
of the heaven to divide the day from the night; and let them be for signs, and for
seasons, and for days, and years:
‘15 And let them be for lights in the firmament of the
heaven to give light upon the earth: and it was so.
‘16 And God made two great lights; the greater light to
rule the day, and the lesser light to rule the night: he made the stars
also …
‘19 And the evening and the morning were the fourth day.’
This passage clearly states that God made the moon on the same day as the sun and
stars — the fourth day of Creation Week. It was also created one day after
the plants. This order of events is impossible to reconcile with evolutionary/billions
of years ideas.
The moon’s purpose
The answer’s in Genesis! A major purpose is to light up the night. The moon
reflects the sun’s light on to us even when the sun is on the other side of
the earth. The amount of reflected light depends on the moon’s surface area,
so we are fortunate to have a moon that is so large. It is over a quarter of Earth’s
diameter — far larger in comparison with its planet than any other in the
solar system.1 Also, if it were much
smaller, it would not have enough gravity to maintain its spherical shape.2
Another reason for the moon is to show the seasons. The moon orbits the earth roughly
once a month causing regular phases in a 29½ day cycle (see diagram below).
So calendars could be made, so people could plant their crops at the best time of
the year.
An important feature is that the moon always keeps the same face towards the earth.3 If different parts were visible
at different times, the moon’s brightness would depend on which part was pointing
towards the earth. Then the 29½ day cycle would be far less obvious.
Tides
The earth’s gravity keeps the moon in orbit, and is so strong that it would
need a steel cable 850 km (531 miles) in diameter to provide an equivalent binding
force without breaking. The moon exerts the same force on the earth. But the force
is somewhat higher on the part of the earth nearest the moon, so any water there
will bulge towards it — a high tide. The part furthest from the moon is attracted
the least by the moon, so flows away from the moon (and Earth’s centre) —
another high tide on the opposite side of the earth. In between, the water level
must drop — the low tides — see diagram below. As
the moon orbits the spinning earth, there is a cycle of two high tides and two low
tides about every 25 hours.
Tides are vital to life on Earth. Tides cleanse the ocean’s
shorelines, and help keep the ocean currents circulating, preventing the ocean from
stagnating. They benefit man by scouring out shipping channels and diluting sewage
discharges. In some places, people exploit the enormous energy of the tides to generate
electricity.4

The Apollo moon landing. Such achievements may be a logical extension
of the dominion mandate given to mankind in
Genesis 1:28. The moon’s utter barrenness should remind us of our
planet’s unique design for life.
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Nice to visit; but to live?
One of the most dramatic events of our time was the landing of men on the moon.
However, they confirmed that it is a lifeless, airless world, with huge temperature
extremes and no liquid water. From the moon, Earth appears as a bright blue-and-white
object in the black sky. Earth is the planet God has designed for life. Man may
be able to live on other worlds one day, but it will be hard to make them habitable.
Many people don’t realise that the man behind the Apollo moon mission was
the creationist rocket scientist Wernher von Braun.5
And another creationist, Jules Poirier, designed some
vital navigational equipment used in the space program.6
How long has the moon been receding?
Friction by the tides is slowing the earth’s rotation, so the length of a
day is increasing by 0.002 seconds per century. This means that the earth is losing
angular momentum.7 The Law
of Conservation of Angular Momentum says that the angular momentum the
earth loses must be gained by the moon. Thus the moon is slowly receding from Earth
at about 4 cm (1½ inches) per year, and the rate would have been greater
in the past. The moon could never have been closer than 18,400 km (11,500 miles),
known as the Roche Limit, because Earth’s tidal forces (i.e., the
result of different gravitational forces on different parts of the moon) would have
shattered it. But even if the moon had started receding from being in contact with
the earth, it would have taken only 1.37 billion years to reach its present distance.8 NB: this is the maximum
possible age — far too young for evolution (and much younger than the radiometric
‘dates’ assigned to moon rocks) — not the actual age.
Could the moon form by itself?
Evolutionists (and progressive creationists) deny the moon’s direct creation
by God. They have come up with several theories, but they all have serious holes,
as many evolutionists themselves admit. For example, lunar researcher S. Ross Taylor
said: ‘The best models of lunar origin are the testable ones, but the testable
models for lunar origin are wrong.’9
Another astronomer said, half-jokingly, that there were no good (naturalistic) explanations,
so the best explanation is that the moon is an illusion!10
- Fission theory, invented by the astronomer George Darwin (son of Charles).
He proposed that the earth spun so fast that a chunk broke off. But this theory
is universally discarded today. The earth could never have spun fast enough to throw
a moon into orbit, and the escaping moon would have been shattered while within
the Roche Limit.
- Capture theory — the moon was wandering through
the solar system, and was captured by Earth’s gravity. But the chance of two
bodies passing close enough is minute; the moon would be more likely to have been
‘slingshotted’ like artificial satellites than captured. Finally, even
a successful capture would have resulted in an elongated comet-like orbit.
-
Condensation theory — the moon grew out of a dust cloud attracted by
Earth’s gravity. However, no such cloud could be dense enough, and it doesn’t
account for the moon’s low iron content.
- Impact theory —
the currently fashionable idea that material was blasted off from Earth by the impact
of another object. Calculations show that to get enough material to form the moon,
the impacting object would need to have been twice as massive as Mars. Then there
is the unsolved problem of losing the excess angular momentum.11
Conclusion
The moon is a good example of the heavens declaring God’s glory (Psalm
19:1). It does what it’s designed to do, and is vital for life on
Earth. It is also a headache for evolutionists/uniformitarians.
When day becomes night …
One of the most fascinating sights in the sky is a total eclipse of the sun. This
is possible because the moon is almost exactly the same angular size (half a degree)
in the sky as the sun — it is both 400 times smaller and 400 times closer
than the sun. This looks like design. If the moon had really been receding for billions
of years, and man had been around for a tiny fraction of that time, the chances
of mankind living at a time so he could observe this precise size matchup would
be remote.12
Moon facts 13
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Mean distance from earth
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384,404 km or 239,000 miles
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Diameter
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3,476 km or 2172.5 miles (0.273 Earth, 1/400 Sun)
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Mass
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7.35 x 1022 kg (0.0123 Earth)
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Density
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3.34 g/cm3 (0.6 Earth)
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Surface Temperature
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204°C (400°F) day, -205° C (-338°F)
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True (sidereal) orbital period
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27.322 Earth days (29.531 day phase cycle)14
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Orbital angular momentum
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2.68 x 1034 kg m2/s (82.9% of earth-moon system)
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Inclination of equator to orbital plane
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6° 41′ (cf. Earth 23° 27′)
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Earth-moon gravitational attraction
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1.98 x 1020 N (2.23 x 1016 tons)
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Click
here for larger image.
The moon’s size and closeness to Earth means it has the greatest tidal effect
on Earth. Even the sun has less than half this effect, and the effect of the other
planets is negligible.* When the sun and moon are aligned, their combined gravity
results in strong spring tides. When they are at right angles, their gravity
partly cancels, resulting in weak neap tides.
* Gravitational force between two objects is given by F = Gm1m2/R2,
where G is the gravitational constant, m1 and m2 are the masses
of the objects, and R is the distance between their centres of mass — an inverse
square law. But the tidal effect drops off far more quickly, with R3
— an inverse cube law. If more people had known this, they wouldn’t
have been scared by knowing all the planets would be roughly aligned in 1982, when
many predicted this would lead to disaster.
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Further reading
References and notes
- Apart from the remote Pluto/Charon system. Return
to text.
- The most stable shape for a massive body is for all parts of the
surface to be the same distance from the centre of mass, i.e. a sphere. The pressure
inside the moon is ten times the crushing strength of granite, so any large unevenness
would be crushed into shape. Such a sphere may bulge at the equator if the body
is spinning fast enough. Return to text.
- That is, its rotational period is identical to its (synodic) orbital
period. This is true of many moons in the solar system, because the planet’s
gravity is always stronger on the nearest side (a tidal interaction), and this will
eventually lock one side so it will always face the planet. The effect is enhanced
if one side is denser than the other. Return to text.
- Fred Pearce, ‘Catching the tide’, New Scientist
158(2139):38–41, June 20, 1998. Return to text.
- See Ann Lamont, 21 Great Scientists who Believed the Bible,
Creation Science Foundation, Australia, 1995, pp. 242–251. Return
to text
- For more details, see his article ‘The
magnificent migrating monarch’, Creation 20(1):28–31,
1997. Return to text.
- Angular momentum = mvr, the product of mass, velocity and distance,
and is always conserved (constant) in an isolated system. Return to text.
- For the technical reader: since tidal forces are inversely proportional
to the cube of the distance, the recession rate (dR/dt) is inversely proportional
to the sixth power of the distance. So dR/dt = k/R6, where k
is a constant = (present speed: 0.04 m/year) x (present distance: 384,400,000 m)6
= 1.29x1050 m7/year. Integrating this differential equation
gives the time to move from Ri to Rf as t = 1/7k(Rf7
— Ri7). For Rf = the present distance and
Ri = the Roche Limit, t = 1.37 x 109 years. There is no significant
difference if Ri = 0, i.e. the earth and moon touching, because of the
high recession rate (caused by enormous tides) if the moon is close. See also Don DeYoung, ‘The Earth-Moon System’, Proceedings
of the Second International Conference on Creationism, Vol. II, pp.
79–84, 1990. Return to text.
- S. Ross Taylor, paraphrased by geophysicist Sean Solomon, at Kona,
Hawaii, Conference on Lunar Origin, 1984; cited in: Hartmann, Wm. K., The History
of Earth, p. 44, Workman Publishing Co., Inc., Broadway, NY, 1991.
Return to text.
- Irwin Shapiro in a university astronomy class about 20 years ago,
cited by J.J. Lissauer, Ref. 10, p. 327. Lissauer affirms that the first three theories
have insoluble problems. Return to text.
- Shigeru Ida et al., ‘Lunar accretion from an impact generated
disk’, Nature 389 (6649):353–357, September
25, 1997; Comment in the same issue by J.J. Lissauer, ‘It’s not easy
to make the moon’, pp. 327–328. Return to text.
- See also D.R. Faulkner, ‘The
angular size of the moon and other planetary satellites: An argument for Design’,
Creation Research Society Quarterly 35(1):23–26,
June 1998. Return to text.
- From John C. Whitcomb and
Donald B. DeYoung, The Moon: Its Creation, Form and Significance, Baker
Book House, Grand Rapids, Michigan, 1978. This book provided many ideas for this
article. Return to text.
- The sidereal period is the time for a complete orbit of the moon
around the earth, relative to an observer outside the solar system. The phase cycle
(synodic period) is the time taken for the moon to return to the same orientation
towards the sun. It is longer because the earth moves about 1/13th of the way in
its orbit around the sun, so the moon must travel further than one true lunar orbit
for a given orientation to recur. (The assistance of astronomer
Dr Danny Faulkner is gratefully acknowledged). Return to text.
(Available in Spanish)
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