by Mike Bara
The second objection is that such an eruption would most likely be from the equatorial region of the Earth. If this were the case, then logically the Moon would orbit around the Earth’s equatorial plane, much like the planets orbit around the Sun’s plane of the ecliptic. Instead, we see that Moon’s orbital plane is tilted 28.5 degrees to the Earth’s equator.
The third objection was that the newly broken away Moon would have had devastating tidal effects on the Earth, and possibly been broken apart as it passed the Earth’s destructive “Roche limit.” It is argued that no evidence of such tremendous tidal disruptions exists in the geologic record today.
Despite all this, the Lunar Fission Theory remained popular well into the twentieth century. One fanciful account from a 1936 U.S. Office of Education script for a children’s radio program told the story this way:
“FRIENDLY GUIDE: Have you heard that the moon once occupied the space now filled by the Pacific Ocean? Once upon a time—a billion or so years ago—when the Earth was still young—a remarkable romance developed between the Earth and the sun—according to some of our ablest scientists … In those days the Earth was a spirited maiden who danced about the princely sun—was charmed by him—yielded to his attraction, and became his bride … The sun’s attraction raised great tides upon the Earth’s surface … the huge crest of a bulge broke away with such momentum that it could not return to the body of mother Earth. And this is the way the moon was born!
GIRL: How exciting!”4
However exciting, the Lunar Fission Theory began to get some competition by the early 20th century. In 1909, an astronomer by the name of Thomas Jefferson Jackson See proposed a new idea; that the Moon had just been wandering by and was somehow “captured” by the Earth’s gravitational pull and settled into a stable orbit. This scenario, while possible, is highly improbable for a number of reasons. First, celestial objects tend to move through the vacuum of space pretty quickly. The Earth, for instance, travels at about 67,108 mph through space, which generates quite a bit of inertia, or momentum. How the Earth’s relatively weak gravitational field could capture another object moving past and pull it into a stable orbit is a problematic question with no easy answer. In an attempt to resolve it, the capture theory was modified so that the Earth in the distant past had a much denser atmosphere that was also much greater in volume. If this had been the case, the dense atmosphere could have helped slow down the wandering Moon, but so far no evidence supporting this proposal has ever emerged.
And there were other problems. Even without the highly expanded atmosphere idea, the intricate celestial dance required to make the capture theory work would be incredibly complex and almost unimaginably coincidental. Since nothing like it has ever been observed anywhere in the universe, it remained a very unlikely possibility even before the astronauts landed on the Moon and brought back rock samples. It was really then that the capture theory completely fell apart.
Logically, if the Moon was just wandering by and somehow magically captured by the Earth’s gravitational field – which remember is weaker than the Sun’s hold on it—then a couple of assumptions therefore follow. The first is that since the Moon by definition would have formed somewhere else, it should not be made up of materials similar to Earth or of the same relative age. That’s where the moon rocks came in. What they showed is that not only is the Moon made up of the same “stuff” as the Earth, it was, like the Earth, formed some 4.5 billion years ago. So all things considered, the capture theory didn’t ever really get off the ground. But it did give rise to another idea, which became all the rage for a period of time in the late 1970’s. This was the “co-accretion theory.”
The co-accretion theory arose from the accretion theory of planetary formation (which I thoroughly dismantled in my last book, The Choice). This idea, initially advocated by the French astronomer Edouard Roche, argues that planets are formed by simply coalescing from the leftover dust and debris of exploded stars. These debris clouds are called “nebula” by the astronomical community, and the idea is that clumps of material begin to form in these primordial nebula, run into each other, magically glue themselves together, and eventually become planets. Roche simply expanded the notion so that the Earth and Moon formed literally side by side, just as we see them today. However, the co-accretion theory cannot account for why the Moon is so much less dense than the Earth, or why it has such a small core and virtually no heavy elements. Logically, if they formed together in the same region of the primordial soup, they should have similar compositions and densities. Not only that, but the CO–accretion theory could not account for the high amount of angular momentum (spin energy) in the Earth-Moon system.
Artists depiction of the capture theory. (NASA)
So, having pretty much struck out by the late 1970’s, the planetary scientists began to seize on a new theory of how the Earth-Moon system formed; the “Big Whack” theory.
Re-dubbed the Giant Impact Hypothesis, this new idea said that a large, Mars sized object struck the Earth sometime in the distant past (about 4.5 billion years ago, by most estimates). This impact ejected a huge amount of material off the Earth and into the Moon’s orbit, where it cooled, coalesced and formed a completely new body we know today as our sister Moon. This massive object is sometimes called Thea, after the Greek Titan that was the mother of Selene, the Moon goddess of ancient Greek mythology. Advocates of the Giant Impact Hypothesis (let’s just call it the GIH from now on) point to what they argue are several lines of evidence to support it. Primary among these are that the Earth’s and the Moon’s orbit are in the same direction (possibly indicating they had a common origin point in the solar system), and the fact (derived from moon rocks brought back the Apollo astronauts) that the lunar surface was once nearly entirely molten.
Of course, there are also problems with the GIH. First, an impact such as the one required to make the GIH work would have probably melted the entire surface of the Earth into a molten magma ocean, at least for a brief period of time. Since there is no geologic evidence that such a global melt ever took place, that finding in of itself pretty much shoots down the GIH theory. Further proof that the GIH is wrong was recently found in the study of titanium oxygen isotopes from the Moon, Earth and meteors. The study, which is kind of a planetary paternity test, found that Moon rocks and Earth rocks had virtually identical oxygen isotopic ratios, meaning that the Earth and Moon are chemically exactly the same. This has two implications; first that the Moon formed from the Earth, and second that there was no giant impacting body that struck the Earth and formed the Moon. If there was, the oxygen isotopic ratios of the Earth and Moon would be different, since it is virtually guaranteed that an object which formed elsewhere in the solar system would not have identical ratios to the Earth’s. In other words, if Thea had truly struck Earth, Thea and Earth’s chemicals and elements would have mixed when the Moon formed, and the Moon would be a compositional mixture of the two. It is not. It is exactly like the Earth, meaning it either formed near the Earth, or was somehow broken away from it.
So much for Thea and the GIH.
Unfortunately, this leaves us without a single viable working theory for how the Moon formed. Or at least, it leaves the planetary geologists and astronomers without one. Fortunately, just as I did in my previous book The Choice, I’m here to sort things out for the planetary geologists and give them a new and more likely theory they can hang their hat on. It’s called the Solar Fission Theory.
The Solar Fission Theory, chiefly advocated by the late Dr. Tom van Flandern in his book Dark Matter, Missing Planets and New Comets: Paradoxes Resolved, Origins Illuminated, argues that the Sun spins off the planets from its belly very early in its life-cycle, and that the planets subsequently give birth to their moons in the same manner. As I described it in The Choice:
“In the solar fission model, once the biggest chunk of the solar nebula collapses and begins nuclear fusion (ignition into a star), it starts sucking up all the nearby dust and g
as and it quickly grows in size. By adding all this fuel to its nuclear furnace, it soon begins spinning so fast that the centrifugal forces become stronger than the gravitational field of the newborn star. At this point, the star “oblates,” or bulges at the center, and solar material is flung out from the equatorial region of the young star. This material then spirals outward in (roughly) twin pairs, forming first gas giant planets and then later “terrestrial” or rocky planets like our Earth. As the star gives birth to pair after pair of twins in this manner, its angular momentum (spin energy) dissipates and the star begins to emit energy in a stable cycle ideal for supporting life giving planets. As the blobs of ejected “star stuff” spiral away from their birth mother, they also give birth in turn to their own moons, and eventually find their resonant orbits and begin to cool. After a billion years or so, the whole system should achieve a state of equilibrium and balance. The planets will cool. On some of them in the habitable zone, like Venus, Earth or Mars, water will form oceans, bacteria will start the cycle of life, and the children of this elegant birthing process will eventually walk the face of these planets, stare into the night sky, and wonder how they got there in the first place.”
The theory then goes on to explain that large gas giant planets like Jupiter and Saturn will tend to spin off multiple moons (in roughly twin pairs) and smaller terrestrial planets like Earth and Venus will tend to spin off only one large moon, much like we see in the Earth-Moon system. In van Flandern’s model, Earth and the Moon are an example of such a pairing, and so are Venus and Mercury, with Mercury having been ejected from its orbit around Venus by some ancient impact.
The chief objection to the idea that the Moon broke off from the Earth was the fact that it would take far more spin energy than the current Earth-Moon system possess to actually break a chunk of solid Earth off. The Solar Fission model also solves this problem. In van Flandern’s model, the Moon didn’t break away from the primordial Earth after it cooled and solidified, it spun off out of the early molten Earth. This would also explain why the Moon is made up primarily of material from the Earth’s lighter mantle, rather than the heavier iron-rich core. The only observation that isn’t accounted for is the fact that the Moon’s orbital plane is inclined by 5.14° to the Earth’s. However, there could be numerous explanations for this (like later impacts which forced the Moon to a different position) and so this is not a show–stopper for the theory.
What does appear to be certain is this; whatever the Moon’s origins, it appears to be either formed from the Earth itself or very nearby at the same time as the Earth, 4.5 billion years ago. Fanciful stories of it being a celestial body from another part of the solar system (or the galaxy) that was “driven” here and placed into orbit are most likely wrong. That does not however preclude it from being inhabited or modified much later in its evolutionary process. For instance, sometime after life began on Earth.
Early Studies and Anomalies
Almost from the dawn of human history, the ancients studied the Moon and began to unravel its secrets. The ancient Greek philosopher Anaxagoras (4th century BC) speculated that the Sun and Moon were both giant spherical rocks, and although he got that wrong, he did correctly surmise that the Moon was visible because it was reflecting the light of the Sun. The Chinese astronomer Shi Shen published instructions for the predictions of both lunar and solar eclipses in the 4th century. Jing Fang (78–37 BC), of the Chinese Han dynasty, also correctly predicted that the Moon was spherical. In the 2nd century BC, Seleucus of Seleucia correctly theorized that tides were due to the attraction of the Moon, and that their height depended on the Moon’s position relative to the Sun. Ptolemy of Egypt (90–168 AD) calculated the distance of the Earth to the Moon and its size relative to the Earth with amazing accuracy. He calculated the Moon was at a distance of 59 times the Earth’s radius and had a diameter of 0.292 Earth diameters. The actual values are 60 and 0.273 Earth diameters. Babylonian astronomers were the first to record the 18-year cycle of lunar eclipses in the 5th century AD. In 499 AD, the Indian astronomer Aryabhata stated in his journal the Aryabhatiya that reflected sunlight is what causes the Moon to shine.
That all of this was discovered or accurately predicted before the invention the telescope is somewhat astonishing. By the time Galileo Galilei made his first drawings of the Moon from his telescopic observations in 1609, most of the world had come to believe that while the Moon was spherical, its surface was probably glass smooth. Galileo was the first to truly insist that it was in fact made up of mountains and valleys – much like the Earth – and that the deep craters visible on its pockmarked surface were probably the results of volcanic activity (which some are) or massive impacts.
Transient Lunar Phenomena (TLP) visible on the Moon. (NASA)
Through this same time period, observers began to note what appeared to be temporary changes in the surface appearance of the Moon. These “Transient Lunar Phenomena” (TLP’s or LTP’s for short) are usually noted as observations of changes in the color or reflectivity of the lunar surface. Since the 1600’s, observers have cataloged at least 579 separate observations of TLP’s, according to one NASA report.5 Most of these events last anywhere from a few minutes to a few hours (hence the “transient” part of the designation) and have a tendency to cluster around certain areas of the lunar surface. The craters Alphonsus and Aristarchus are the two most commonly mentioned in the literature.
Descriptions of TLP’s range from foggy patches to what appear to be mist-like or cloudy formations or other forms of obscuration of the lunar surface. Changes in coloration ranging from red, green, blue or violet have been noted, as have areas of increased brightness or areas of increased darkness. Two extensive catalogs of TLP’s exist, with the most recent cataloging some 2,254 events going back to the 6th century. Of those that are considered the most reliable reports, about 1/3 come from the vicinity of the previously mentioned Aristarchus plateau.
Wikipedia lists some of the more well-known examples of TLP reports as follows:
On June 18, 1178, five or more monks from Canterbury reported an upheaval on the moon shortly after sunset. “There was a bright new moon, and as usual in that phase its horns were tilted toward the east; and suddenly the upper horn split in two. From the midpoint of this division a flaming torch sprang up, spewing out, over a considerable distance, fire, hot coals, and sparks. Meanwhile the body of the moon which was below writhed, as it were, in anxiety, and, to put it in the words of those who reported it to me and saw it with their own eyes, the moon throbbed like a wounded snake. Afterwards it resumed its proper state. This phenomenon was repeated a dozen times or more, the flame assuming various twisting shapes at random and then returning to normal. Then after these transformations the moon from horn to horn, that is along its whole length, took on a blackish appearance.” In 1976, Jack Hartung proposed that this described the formation of the Giordano Bruno crater.
During the night of April 19, 1787, the famous British astronomer Sir William Herschel noticed three red glowing spots on the dark part of the moon. He informed King George III and other astronomers of his observations. Herschel attributed the phenomena to erupting volcanoes and perceived the luminosity of the brightest of the three as greater than the brightness of a comet that had been discovered on April 10. His observations were made while an aurora borealis (northern lights) rippled above Padua, Italy. Aurora activity that far south from the Arctic Circle was very rare. Padua’s display and Herschel’s observations had happened a few days before the sunspot number had peaked in May 1787.
In 1866, the experienced lunar observer and mapmaker J. F. Julius Schmidt made the claim that Linné crater had changed its appearance. Based on drawings made earlier by J. H. Schröter, as well as personal observations and drawings made between 1841 and 1843, he stated that the crater “at the time of oblique illumination cannot at all be seen” (his emphasis), whereas at high illumination, it was visible as a bright spot. Based on repeat observations, he further stated t
hat “Linné can never be seen under any illumination as a crater of the normal type” and that “a local change has taken place.” Today, Linné is visible as a normal young impact crater with a diameter of about 1.5 miles (2.4 km).
On November 2, 1958, the Russian astronomer Nikolai A. Kozyrev (prominently mentioned in The Choice) observed an apparent half-hour “eruption” that took place on the central peak of Alphonsus crater using a 48-inch (122-cm) reflector telescope equipped with a spectrometer. During this time, the obtained spectra showed evidence for bright gaseous emission bands due to the molecules C2 and C3. While exposing his second spectrogram, he noticed “a marked increase in the brightness of the central region and an unusual white colour.” Then, “all of a sudden the brightness started to decrease” and the resulting spectrum was normal.
On October 29, 1963, two Aeronautical Chart and Information Center cartographers, James A. Greenacre and Edward Barr, at the Lowell Observatory, Flagstaff, Arizona, manually recorded very bright red, orange, and pink colour phenomena on the southwest side of Cobra Head; a hill southeast of the lunar valley Vallis Schröteri; and the southwest interior rim of the Aristarchus crater. This event sparked a major change in attitude towards TLP reports. According to Willy Ley: “The first reaction in professional circles was, naturally, surprise, and hard on the heels of the surprise there followed an apologetic attitude, the apologies being directed at a long-dead great astronomer, Sir William Herschel.” A notation by Winifred Sawtell Cameron states (1978, Event Serial No. 778): “This and their November observations started the modern interest and observing the Moon.” The credibility of their findings stemmed from Greenacre’s exemplary reputation as an impeccable cartographer. It is interesting to note that this monumental change in attitude had been caused by the reputations of map makers and not by the acquisition of photographic evidence.