Read Who Built the Moon? Online
Authors: Christopher Knight,Alan Butler
Who Built the Moon? (6 page)
The suggestion seems to have many merits. First and foremost it appears to address the greatest puzzle that the recovery of Moon rock had thrown up: How was it that the composition of the Moon was so similar to that of the Earth, but only in part?
A close analysis of Moon rock has shown that it is very similar to the rock that forms the mantle of the Earth, yet the Moon is nowhere near as massive as the Earth in proportional terms. (The Earth is only 3.66 times as big as the Moon but has eighty-one times the Moon’s mass.) It was obvious that the Moon could not contain many of the heavy elements that are found inside the Earth and the Big Whack theory purported to explain why this was the case. The Earth and the rogue visitor had come together in a very specific way. Although they would eventually form one planet it was reasoned that they must have impacted, drawn apart and then come together again. Computer modelling showed that under these very special circumstances it would have been possible for the material thrown off to have been mantle material, from close to the surface of the two bodies.
Although the theory eventually gained ground, at first it seemed so improbable that it was generally rejected. But with the passing of time, further work showed that such an unlikely scenario could conceivably have taken place. In 1983 an international conference was held at Kona, Hawaii, to try and solve the problems regarding the origins of the Moon. It was at this meeting that the Big Whack theory, also known as the Giant Impact Hypothesis of the Collision Ejection theory, began to gain ground. Hartmann’s own suggestions, together with those of other scientists at the conference, formed the nucleus of the 1986 book,
Origin of the Moon
, which was edited by Hartmann himself.
In the intervening period several experts have created computer models that purport to add weight to the Big Whack theory and the most convincing of these are those of Dr Robin Canup, who is now Assistant Director of the Department of Space Studies in Colorado, USA. Canup wrote her PhD dissertation on the Moon’s origin and specifically the Big Whack theory. Her early work led to the conclusion that the suggested impact would have actually led to a swarm of moonlets, rather than the Moon, but by 1997 further computer modelling resulted in a model of the impact that would lead to the Moon’s presence.
Despite the fact that the Big Whack theory is now generally accepted by most authorities, it has many problems. Not least of all is that recognized by Robin Canup herself as she admits that there is one key aspect of the theory that doesn’t make sense. This stems from the fact that other researchers have pointed out that such a massive impact as that proposed could not have failed to speed up the rotation of the Earth to a level far beyond today’s situation. Canup agrees and the only way that she could deal with this anomaly is to propose a second major impact – which was designated ‘Big Whack II’. This suggests that the second planetary collision happened perhaps only a few thousand years after the first one but, quite incredibly, this incoming object came from the opposite direction and so cancelled out the huge spin imparted to the Earth by the first cataclysmic event. This balanced double act sounds unlikely in the extreme. Two cosmic collisions that just happen to precisely return the planet to its natural rhythm? To us, this explanation smacks of desperation!
Canup herself is not happy with Big Whack II and is hopeful of modifying the original theory so that it can account for the present rate of spin of the Earth.
There is another big problem to overcome if the Big Whack theory is to be taken seriously. When rocks were brought back from the Moon, both by American astronauts and Soviet unmanned Moon missions, they were subjected to every conceivable test. The observed fact that put paid to the captured asteroid theory of the Moon is also a gigantic stumbling block to the Big Whack theory. It has been observed that the oxygen isotope signatures of Moon rocks are identical with those of rocks from the Earth – and that fact has some serious implications: Moon rocks and Earth rocks can only have the same oxygen isotope signature if they originated at the same distance from the Sun. This would mean that the Mars-sized body that hit the Earth must have occupied a similar orbit to that of the Earth and yet had already managed to survive for many millions of years before it hit the Earth.
That does not sound reasonable.
This situation is extremely unlikely and it throws up other difficulties. The present obliquity of the Earth (its twenty-three degree tilt against the plane of its orbit around the Sun) is usually deemed to be the result of the giant impact, but any body of the size of Mars that was in an orbit similar to that of the Earth could not have had sufficient momentum to knock the Earth’s angle of rotation back so severely. Either the rogue planet was Mars-sized, and came from way out in the solar system and was therefore travelling extremely fast, or else it had to be at least three times the size of Mars, which doesn’t tie in with the computer models as they stand.
Some of the other problems were cited by Jack J Lissauer, a well-respected scientist from NASA’s Ames Research Center in an article he wrote for
Nature
in1997.
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Lissauer is said to have joked to his students about a remark made by another scientist, Irwin Shapiro from the Harvard-Smithsonian Center for Astrophysics: ‘The best explanation for the Moon is observational error – the Moon does not exist!’
Lissauer’s article pointed out some of the problems with the Big Whack theory. He made it clear that in his opinion the latest research demonstrated that much of the material blown out by the impact (the ejecta) would have fallen back to the Earth. He says:
‘The implication here is that lunar growth in an impact-produced disk is not very efficient. So, to form our Moon, more material must be placed in orbit at a greater distance from Earth than was previously believed.’
Lissauer made it clear that as a result, he too is of the opinion that the rogue planet must have been substantially larger than that originally proposed but noted that it is difficult to see how the excess angular momentum resulting from such a large impact could have been lost.
Three other scientists, Ruzicka, Snyder and Taylor, approached the problem from a slightly different direction by analysing the biochemical data available against the theoretical Big Whack. After a detailed examination they concluded: ‘There is no strong geochemical support for either the Giant Impact or Impact-triggered Fission hypotheses.’
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These words used in the conclusion to this biochemical analysis indicate just how hopelessly contrived the whole Big Whack theory is. They go on to say: ‘This [hypothesis] has arisen not so much because of the merits of [its] theory as because of the apparent dynamical or geochemical short-comings of other theories.’
In other words scientists hang onto the Big Whack theory, even though it has more holes than a rusty colander, simply because no other logical explanation has been found. It is just the least impossible explanation for a celestial body that has no right to be there.
Not only is the Big Whack theory discredited on a number of grounds by the scientific fraternity itself, it also singularly fails to deal with the anomalies thrown up by our own research, as outlined throughout this book. Big Whack cannot explain the extraordinary ratio relationship between the Moon and the Sun or the Moon and the Earth. The Moon could, by pure chance, end up being exactly 1/400
th
the size of the Sun and occupying an orbit that allows it to stand 1/400
th
the distance between the Earth and the Sun – but the odds are, quite literally, astronomically against it.
The Moon is proportionally bigger in relation to its host planet than any other in the solar system apart from Charon, Pluto’s moon, which is more than half the diameter of Pluto. These two bodies are essentially twin planets or may be asteroids orbiting each other at close range although they are believed to have an unrelated origin.
Mercury has no moons at all and neither has Venus. Mars does have two moons but they are tiny in comparison with our own.
A close examination of the many samples of Moon rock brought back by the American Apollo missions and the Soviet unmanned missions has thrown up what turned out to be one of the biggest surprises of all. It has been observed that the oldest of the rocks collected from the Moon are significantly more ancient that any rock ever found on Earth. The most venerable rocks to be found on the Earth date back 3.5 billion years, whilst some samples from the Moon are around 4.5 billion years old – which is very close to the estimated age of our solar system. When radioactive dating techniques are applied to meteorites they are uniformly found to be 4.6 billion years old.
Yet even these rocks have the same oxygen isotope signature as those on Earth, another indication that the Moon has occupied its present distance from the Sun for an incredibly long time. There is currently no persuasive argument for this state of affairs.
Our own, almost accidental, discoveries regarding the peculiar ratio relationships between the Earth, Moon and Sun described in our previous book,
Civilization One
,
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led us to an in-depth appraisal of the latest theories regarding the Moon and its origins. We were stunned by what we discovered. The Moon is bigger than it should be, apparently older than it should be and much lighter in mass than it should be. It occupies an unlikely orbit and is so extraordinary that all existing explanations for its presence are fraught with difficulties and none of them could be considered remotely watertight. We came to realize that many reputable experts across the world have significant misgivings about current theories concerning the Moon’s origins that, as we have shown in this chapter, they were quite willing to voice publicly.
No matter how much the advocates of the Big Whack theory may claim they have solved the puzzle that is the Moon, it is quite obvious that this claim is far from being true. The Moon remains, to borrow the words of Winston Churchill, ‘a riddle wrapped in a mystery inside an enigma’.
Walking On The Moon
‘We choose to go to the moon.’
President John F Kennedy: September 12
th
, 1962
After the end of the Second World War, rocket scientists from Germany were ‘liberated’ by both the United States and the Soviet Union, and by the beginning of the 1950s these experts were put to work on creating weapons of various sorts that would fuel the Cold War between the Eastern communists and the Western capitalists. On the American side the most famous of the German experts was Vernher Von Braun who had created the V1 and V2 rockets for Nazi Germany and who eventually went on to design the Saturn V rocket that would take people to the Moon.
At the outset the USA focused its attentions on developing new types of small but immensely powerful hydrogen bombs based on nuclear fusion whilst the USSR continued to refine the older and much heavier fission bomb. The Soviets therefore had to develop more powerful rockets and the R-7 missile, capable of carrying a five-tonne warhead, was the result. Their Chief Designer, Sergei Korolyov, realized that these rockets would also be capable of putting a one-and-a-half tonne satellite into Earth’s orbit and he put forward his plan for such a mission.
Korolyov’s project was well under way when news came that the US was developing its own satellite launch, known as Project Vanguard. This new challenge set up a ‘race to space’ and Korolyov’s main satellite project was temporarily suspended as all efforts became focused on the early launch of a smaller artificial satellite that could be built far more quickly. Sputnik lifted into the skies on October 4
th
1957.
This first spacecraft was a forty-pound sphere that carried a simple transmitter so that it could make meaningless, but technical sounding, bleeping sounds at which the world could marvel. The acclaim and sheer excitement caused by Sputnik’s success led the Soviet leader, Nikita Khruschev, to demand more high-profile stunts rather than a return to serious science. The team responded immediately by screwing together the original Sputnik’s backup spares to create a second Sputnik. They had only a few weeks as they were instructed that the next launch must happen before November 7
th
– the fortieth anniversary of the Great October Revolution.
Sputnik 2 was something of a botched job but it captured the imagination of the planet because it took off four days ahead of the anniversary and, amazingly, it was carrying a passenger: a dog called Laika. Unfortunately for this canine hero, her ticket was strictly one way because this hastily assembled craft had no mechanism for a controlled return to Earth – so the animal was destined to die in orbit from the outset. It is thought that she lived for four days in space before suffering a painful death as the cabin overheated. The fatality was part of the plan and the mission was considered a success as it proved that a living creature could survive the journey into orbit. So despite the fact that Sputnik 2 was initiated as a publicity stunt it was an important prelude to a human being making the trip.
The first two Sputniks were therefore politically inspired projects carried out by Sergei Korolyov under orders from the Kremlin and it was not until May 15
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1958 that his original spacecraft was launched – now designated Sputnik 3. This was a serious piece of equipment that was an automated scientific laboratory. It carried twelve instruments providing data on pressure and composition of the upper atmosphere; concentration of charged particles; photons in cosmic rays; heavy nuclei in cosmic rays; magnetic and electrostatic fields; and meteoric particles. And it was Sputnik 3 that first detected the presence of the outer radiation belts that surround the Earth.
The United States was highly embarrassed by the Soviet achievements, and particularly so because it was having little success with its own rocket launchers. So many of them blew up on the launch pad or during takeoff that the world’s press variously dubbed the American space mission ‘Kaputnik, Flopnik, and Stayputnik’.