20.04.2021

Science refutes the claim made by some that the Moon is a hollow spaceship engineered by aliens.

Poe's Law can be roughly paraphrased as there are some views so extreme that they cannot reliably be distinguished from parody, and the claim that the Moon is a hollow alien construction perfectly illustrates the need for such a law. World famous conspiracy theorists such as David Icke have promoted this claim as fact, and fringe websites today continue to publish articles that assign it the unearned status Hollow Moon Theory. Today we're going to disassemble this alleged construction project, and learn exactly how we know that the Moon is neither hollow, nor was it engineered.

However, while it's easy to simply assert "That's not true", how many of us can convincingly explain how and why we know that? Would you be able to sit down right now on a panel and debate a Hollow Moon expert, who's written whole books on the subject? Suddenly we're not nearly the experts we think we are. What seems like a science fantasy idea out of a children's book suddenly looks like a gaping hole in our basic science literacy.

It probably comes as no great surprise that the early advocacy for this idea came from the former Soviet Union, a place where pseudoscientific ideas have found warm receptions not only among the fringe but also in the legitimate scientific community. Two members of the Soviet Academy of Sciences, Michael Vasin and Alexander Shcherbakov, published an article in the mass-market consumer publication Sputnik. In it, they made a few observations about the Moon and then gave what was essentially the plot from the Star Trek episode "For the World Is Hollow and I Have Touched the Sky" which had aired about 18 months previously:

OUR HYPOTHESIS: The Moon is an artificial Earth satellite put into orbit around the Earth by some intelligent beings unknown to ourselves. We refuse to engage in speculation about who exactly staged this unique experiment, which only a highly developed civilization was capable of.

If you are going to launch an artificial sputnik, then it is advisable to make it hollow... What we have here is a very ancient spaceship, the interior of which was filled with fuel for the engines, materials and appliances for repair work, navigation, instruments, observation equipment and all manner of machinery... In other words, everything necessary to enable this "caravelle of the Universe" to serve as a kind of Noah's Ark of intelligence, perhaps even as the home of a whole civilization envisaging a prolonged (thousands of millions of years) existence and long wanderings through space (thousands of millions of miles).

They also cited a 1959 claim by another Soviet scientist, Iosif Shklovsky, who had made the same arguments for Mars' moon Phobos. Soviet politics and science had always been closely intertwined, and their work came at a time when this tide was shifting away from belief in ancient aliens, perhaps in response to the West's new-found love for the subject driven by authors like Erich von Däniken. Thus was their work relegated to the consumer magazine, and thus it was essentially ignored by the scientific community.

But one can always trust in today's Internet conspiracy theory community to breathe new life into just about any old claim, so long as it's contemptuous of any standard model of science. The claims made today, as elucidated in one heavily linked and shared article on the website Ancient Code, include:

• The Moon has unexpected elements that it shouldn't have (not true);
• The Moon does not have a solid core (not true);
• The Moon is older than the Earth (not true);
• The Moon's orbit is perfectly circular (not true).

Let's talk about these.

We went into great detail on the early history of the Earth and the Moon in episode #638, which examined the notion that the early Earth may have had enormous tides rushing across its surface at supersonic speeds multiple times a day, back when the Moon was much closer and orbited much faster. (It's a cool episode, you should check it out.) The moon was formed when two primordial planetesimals, Theia and Gaia, collided. Theia and Gaia had been on the same orbit around the sun, and had accreted from the same material in the early solar system, thus they consisted of about the same minerals in about the same proportions. When they collided, the bulk of the combined mass stayed together and became the Earth while the rest was ejected outward and then accreted into the Moon. Thus, the Earth and the Moon are a pretty good mix of most of the same elements, but not a perfect mix. Both Theia and Gaia had most of the heavier elements deeper inside and their lighter elements further toward the surface, and most of the ejecta from the collision consisted of these lighter elements. The Earth got most of the heavier core elements, while the Moon is made up mostly of the lighter ejecta. Today we have pretty accurate measurements of both: The Earth has a mean density of 5.5 g/cm³ while the Moon measures 3.3 g/cm³, just about 60% as dense.

It is this compositional similarity that forms the backbone of our evidence that the Earth and Moon have this common origin from the same basic place in the solar system, chemically and isotopically distinct from all the other neighborhoods. If some aliens were going to build a gargantuan Ark and park it in orbit around the Earth, and they wanted to fool us by constructing it of the same minerals Earth is made from, they would have first needed to come here and take samples, and then gone out and found another planet exactly like the Earth to use as their raw materials. I've not yet come across a persuasive argument for why said aliens would have gone to all this expense and trouble, but the leading piece of evidence comes from a source loaded with authority.

The Moon "Rang Like a Bell"

The classic claim that all of the articles promoting this idea put forward, and that even David Icke made, is that the Moon "rang like a bell" when struck. In 1969, Apollo 12 deliberately crashed their lunar ascent stage into the Moon as part of a seismological experiment to learn about the Moon's interior. Astronauts from Apollo 11 and 12 had placed seismometers on the Moon in preparation for this. Writing in a 1970 article in Popular Science, Dr. Wernher von Braun infamously described what happened:

The astounding result of that crash: The moon rang like a bell for nearly an hour, indicating some strange and unearthly underground structure.

Thanks to that unfortunately artistic choice of language, Von Braun himself became perhaps the most influential promoter of this mythology, if an unwitting one. His wording became a rallying cry for the Hollow Moon community, who consider this description of the Moon's ringing — from no less an authority than Wernher von Braun — as proof that the government knows the Moon is hollow like a bell or gong.

But many years later, we now have actual analysis of the data Von Braun so colorfully alluded to, and seismology is indeed one of two main lines of evidence proving that the Moon has a conventional planetary structure.

Seismological Studies

Apollo astronauts placed more seismographs at more locations on later missions, and this network, called the Apollo Passive Seismic Experiment, recorded the Moon's seismological activity until 1977. We're able to study that data to learn about the Moon's internal structure exactly the same way we do here on Earth, observing the different ways that seismological waves reflect off the internal layers inside the planet. In work published in 2011, NASA used state of the art techniques to re-analyze this Apollo era data, and improved the state of our knowledge to give us the best picture yet of the Moon's internal structure. As a result, we have accurate constraints on the range of sizes of its small solid inner core and fluid outer core, a thin partial melt layer, and its thick mantle that constitutes the bulk of its mass.

The Moon's Moment of Inertia

The other great way we can tell whether the Moon is hollow or not is by measuring its moment of rotational inertia. If you're holding a heavy metal globe, you can feel its moment of inertia by trying to rotate it back and forth quickly. If this is easy to do, it means a lot of the mass is concentrated at the center of the globe; if it's harder to do, it means a lot of the mass is out at its surface; it if required a medium effort, it would mean the mass is evenly distributed as if it's a solid body. If the Moon were solid with a heavy core, it would have lower rotational inertia; but if it were a hollow spaceship with a thick outer shell, it would have a higher inertia even if it had the exact same mass.

Now we don't have a giant pair of hands with which we can reach out and try to turn the Moon back and forth to test its moment of inertia, but we still have at least two ways we can measure it. The first is by gravimetric studies. We have spacecraft that orbit the Moon, and by studying how their orbits are affected, we can build a detailed gravimetric profile of the Moon that tells us how dense its various layers are. The second is more complex and involves detailed studies of the way the Moon wobbles. As the Moon orbits the Earth, rotating in sync to keep one side always facing us, there are all kinds of slight variances. It speeds up and slows down on its elliptical orbit, and its movement goes through three different types of precession: axial, apsidal, and nodal. Bottom line is the Moon is always nodding just slightly toward us, to the north, south, east, or west, called libration — and by comparing the observed libration with what the precessions predict we can measure exactly how much inertial resistance the Moon is putting up.

What these measurements have told us is that the Moon's core is dense and small, and that the rest of the Moon is of a pretty uniform density. It is absolutely, positively, not hollow, and has its mass evenly distributed throughout it but for a small heaviest bit at the core; and this is math, not a guess or an assumption.

To sum up: The Moon is not hollow, and if it was engineered by some advanced alien race, what they constructed matches exactly the materials and structure that we'd expect to find if the Moon had formed naturally as given in the standard model, and it was placed into exactly the right orbit that we would expect if that formation had taken place when we believe it did. So, kudos to them for probably the most pointless and expensive project in the history of the universe.

Quelle: Skeptoid