With the Name Allah, the Gracious, the Compassionate





      A Speculative Essay on the Origin of the Moon

    by Hakeem Muhammad


                At 10:00 a.m. on August 27, 1883, climaxing three months of violent activity, Krakatoa exploded.  This Indonesian volcano propelled ash to a height of 50 miles and threw nearly 5 cubic miles of rock fragments into the air.  By the next morning, the volcano was quiet.  A mountain 6,000 feet above sea level had been reduced to 2,667 feet.


                Is it possible that the same forces that caused the catastrophic self-destruction of Krakatoa one century ago caused a volcanic eruption 4.5 billion years ago so massive that over one percent of the Earth's mass was thrown into orbit?  This "birth by volcanic ejection" is my proposed theory for the origin of the Moon.


Theories of Lunar Origin


                There are four basic hypotheses of how the Moon was formed.


                "Sister" Theory (Circumterrestrial Coagulation).  This theory is that the Earth and the Moon evolved together out of the same cloud of debris.  This theory fails to explain: (1) the accumulation of the Moon's present angular momentum; (2) the obliquity of the Moon's orbit; and (3) the formation of two planets instead of one.


                "Wife" Theory (Orbital Capture).  This theory is that the Moon did not come from Earth but from elsewhere in the solar system and was captured into orbit around the Earth during a close approach.  This theory fails to explain: (1) how a body as massive as the Moon could have been captured by the Earth while its velocity and angular momentum were increasing as a result of the Earth's gravitational attraction; and (2) the similarity in composition of the Earth and the Moon.


                The Collision Theory.  This theory is that a Mars-sized planetary body collided with the Earth in a grazing collision which caused the ejection into orbit of part of the Earth's mass.  This theory is currently popular.  In my opinion, this theory calls for the presence of noticeable amounts of similar anomalous materials in the composition of both the Earth and the Moon.  Just as meteorites of asteroidal origin are clearly distinguishable from meteorites of Martian origin (as have been found in Antarctica), similarly crustal materials originally from an alien planetoid should be distinguishable from crustal materials native to the original Earth.


                "Daughter" Theory (Terrestrial Fission).  Originally proposed by Charles Darwin, this theory is that solar tides caused a rapidly spinning fluid spheroid (the primordial Earth) to become rotationally unstable and break in two.  This theory has been discounted because: (1) such rotational instability is unlikely; (2) it fails to explain the accumulation of the Moon's current angular momentum; and (3) it fails to explain the obliquity of the Moon's orbit.



A Revived Daughter Theory


                Volcanic Activity.  My proposed theory is a "daughter" theory of the birth of the Moon, with volcanic activity at a catastrophic level as the cause.  I am suggesting that the Moon is the ejecta of a volcanic eruption.  In effect, the Earth blew itself apart.


                Earth's Instability.  The Earth is unstable.  There are constant Earthquakes, volcanic eruptions, lava flows, and other events, frequently at a catastrophic level, indicating powerful internal processes as the cause for crustal instability.  Planet-wide, there are indications that in the past the instability has been more pronounced.  The Deccan Traps of India, for example, were produced by thousands of years of catastrophic lava flows.  Today, what remains are thousands of square miles of volcanic rock, thousands of feet deep.  Sixty-five million years ago, the intensity of these eruptions must have poisoned the atmosphere and the ocean, and blocked out the Sun, killing most life on Earth.



                Radioactive Decay as a Source of Instability.  Radioactivity generates the heat which causes these phenomena.  Uranium 235 has a half-life of 4.5 billion years.  This means that 4.5 billion years ago, when the Earth was young, there was twice as much of this radioactive material in the Earth's surface layers when the Earth was born.  Similar considerations reveal that there was 17 times as much U‑238 and even greater multiples of other radioactive materials.  In its early life, not only was the Earth hot from the heat of coalescence and bombardment, but also from the heat of much more radioactivity than today.


                Can a Rocky Planet Be Too Large?  The Earth is the largest rocky planet.  Smaller planets of this type ‑‑ the Moon, Mercury, Mars, Venus ‑‑ show evidence of similar phenomena.  Quakes, lava flows and volcanoes in particular.  Is it possible that the Earth is as large as a rocky planet can be without blowing up?  (Is it possible that the large, heavy cores of Uranus and Neptune are the cause of excess heat and instabilities in those planets?)  The additional mass of the Moon, and other material that was ejected explosively, may have pushed the primeval Earth over some limit of viability.  There would have been even more radioactive materials and a slower loss of heat.  A greater accumulation of explosive potential.




                1.             Similar Composition of Earth and Moon.  The Earth and the Moon consist of similar materials.  This tends to rule out the "wife" (separate origin) theory.


                2.             Lack of Anomalous Materials.  Extensive study of the Earth and preliminary studies of lunar materials have not discovered anomalous materials (except in relatively minute amounts) in the crusts of either body.  This tends to rule out the collision theory.


                3.             The Moon Consists of Volcanic Materials.  The Moon is made of basalt ‑‑ volcanic rock.  The distinctive characteristic of lunar materials ‑‑ lack of volatiles, excess of refractories ‑‑ supports a theory of volcanic origin and tends to undermine the "sister" (common birth) theory.


                4.             The Moon is Light.  The Moon's lack of a heavy Earth-like core (or a proportionately heavier core like that of Mercury) is evidence for a lunar birth from the outer layers of a pre-formed Earth.


                5.             Orbital Obliquity.  The obliquity of the lunar orbit, while it tends to rule out Darwin's "daughter" theory (and the "sister" theory), can be explained by this revived "daughter" theory based on volcanic activity.  If (speculatively) the Pacific basin is taken to suggest the original site of an explosive ejection, then it might be that the event occurred not on the equator but south of it.  (Although the Pacific Ocean floor has been "re-paved" by tectonic activity, the Pacific basin continues to be volcanically super-active.  In addition, projections of continental drift into past eons always leave what would today be the Pacific basin on the outside of combining and recombining land masses.  It seems to be a permanent fixture.  Why?)





                My sources have been, for the most part, the popular news magazines, Science Times (The New York Times, Tuesday section), Scientific American, The Sciences (publication of the New York Academy of Sciences, November/December 1990 issue), Planetary Landscapes (by R. Greeley; Allen & Unwin, Boston, rev. ed. 1987), The Solar System (by Roman Smoluchowski; Scientific American Library, New York, 1983), The Encyclopaedia Britannica (vol. 27, pp. 504-507, 517-561; 15th edition, 1985).

(Written sometime between 1989 and 1991)