Hollow Moon Theory

I know this has been discussed before, but all of the threads concerning this topic seemed to be fairly old. I love reading through old threads (some will be referenced throughout this post), and I thought I would compile together what I have learnt so far to see what others think about this theory. I'll try to present all sides of the argument and keep it as balanced and factual as possible, but I don't think this theory is totally crazy; the Moon does have some really odd features, take for instance the "coincidental" math shown in this picture[1]:



The first piece of evidence that suggested the Moon might be hollow appeared in November, 1969, after seismometers were set up on the moon's surface by the astronauts of Apollo 12. As the astronauts took off for Earth, the ascent stage of the lunar module was discarded and it fell onto the moon's surface. It created a tremor that was picked up by the seismometers. NASA found that the Moon was "ringing like a bell" and continued to do so for around an hour[2].

NASA started placing seismometers on the Moon starting in 1969, and those instruments were monitoring seismic activity on the Moon up until 1977 when they were switched off. Even the "moonquakes" caused reverberations through the moon that would last a remarkably long time. NASA explains that the extended length of these vibrations is most likely cause by the composition of the Moon[3].

Furthermore, shallow moonquakes lasted a remarkably long time. Once they got going, all continued more than 10 minutes. "The moon was ringing like a bell," Neal says.

On Earth, vibrations from quakes usually die away in only half a minute. The reason has to do with chemical weathering, Neal explains: "Water weakens stone, expanding the structure of different minerals. When energy propagates across such a compressible structure, it acts like a foam sponge—it deadens the vibrations." Even the biggest earthquakes stop shaking in less than 2 minutes.

The moon, however, is dry, cool and mostly rigid, like a chunk of stone or iron. So moonquakes set it vibrating like a tuning fork. Even if a moonquake isn't intense, "it just keeps going and going," Neal says. And for a lunar habitat, that persistence could be more significant than a moonquake's magnitude.

But what if that isn't the real reason why the Moon vibrates in such a way... is there any other reason to believe the Moon might be hollow? Well if the Moon were hollow, then the density, measured as Mass/Volume, should give us a hint. A low density would indicate the Moon is either hollow or consists of mostly low density materials. As it turns out, the Moon is indeed only 60% of the density of the Earth[4], so almost half as dense. Now if you research how the Moon was created, the most widely accepted theory amongst scientists is the "Giant Impact Hypothesis"[5].

The giant impact hypothesis states that the Moon was created out of the debris left over from a collision between the Earth and a Mars-sized body, sometime around 4 Ga (four billion years ago).

So if the Moon is essentially made of the same stuff as Earth, one might wonder why it is so much less dense compared to Earth. Well lets turn to our resident expert Phage to see what he has to say about it. According to him, the Moon is much less dense because its iron core is a lot smaller than that of Earths[6].

Originally posted by Phage
The seismic experiments carried out on the Apollo missions showed that the Moon is composed almost entirely of material comparable in density to that of Earth's mantle. The average density of the moon is less than earth because it has a very small iron core in comparison to Earth.

The Moon's density is fairly uniform throughout and is only about 3.3 times the density of water. If it has an iron core, it is less than 800 kilometers in diameter. This is a sharp contrast from planets like Mercury and the Earth that have large iron-nickel cores and overall densities more than 5 times the density of water. The Moon's mantle is made of silicate materials, like the Earth's mantle, and makes up about 90% of the Moon's volume.

www.astronomynotes.com...

According to some complex computer analysis carried out last year, there is some proof that the Moon does in fact have a core much like that of Earths[7], though obviously much smaller:

State-of-the-art seismological techniques applied to Apollo-era data suggest our moon has a core similar to Earth's. Uncovering details about the lunar core is critical for developing accurate models of the moon's formation. The data sheds light on the evolution of a lunar dynamo -- a natural process by which our moon may have generated and maintained its own strong magnetic field.

The team's findings suggest the moon possesses a solid, iron-rich inner core with a radius of nearly 150 miles and a fluid, primarily liquid-iron outer core with a radius of roughly 205 miles. Where it differs from Earth is a partially molten boundary layer around the core estimated to have a radius of nearly 300 miles. The research indicates the core contains a small percentage of light elements such as sulfur, echoing new seismology research on Earth that suggests the presence of light elements -- such as sulfur and oxygen -- in a layer around our own core.

Again, this is the mainstream explanation, and it is still just a theory. Of course the iron core of the Moon is going to be much smaller than that of Earths, because the Moon is much smaller. So the average density should still be fairly close to that of Earth from what I understand; what is actually important the ratio of the iron core compared the the size of the body it resides in. Unless that ratio is significantly smaller for the Earth, I don't think the Moon should be lacking so much density. Also consider that 0.02% of Earth is made up of water[8], which is not a very dense substance - while the Moon has virtually no water at all.

So that is basically as far as I got, I am still not convinced that that the Moon is actually hollow, nor am I convinced that the Moon is actually solid right through. I am looking forward to seeing what you guys can add to this discussion, because I think it's possible to solve this mystery with some math and logical thinking. Is the Moon really of such a low density because it is hollow? Does the Moon vibrate so long when struck because it is hollow? Or do you believe the mainstream explanations are correct?

References

1. Hollow Moon Theory facts
2. Has anyone heard of the Hollow moon theory?
3. Moonquakes - NASA Science
4. Moon Fact Sheet
5. Giant impact hypothesis - Wikipedia
6. Post by Phage
7. The Moon's Earth-like Core
8. What Percent of Earth is Water?

Great thread, I have always believed that our Moon is a "observation station", or a way-point base.

There are so many anomaly's that have been observed over the centuries, while studying the Moon - and plenty of NASA, and Soviet recordings and pictures that show at least something is up there.

I know either Extraterrestrials or Extra-Dimensional beings are flying around/on our planet, the literature and the Gems of evidence we have available (some of the best from our government's own archive's) are more than enough to prove that "someone" has been flying for a lot longer than we have

Also, I have a book I would recommend to the OP or to anyone interested in the Moon - Amazon

Its a book co-authored by Christopher Knight and Alan Butler - They discovered a possible correlation between ancient units of measurement, and the dimensions of the Moon and Earth - Well worth a look.
ATS thread on "Who Built The Moon?"

reply to post by Soapusmaximus

They discovered a possible correlation between ancient units of measurement

Interesting. Would one of the ancient units of measurement happen to be the cubit by chance?

I also second the book mentioned above;fascinating read.

Hi OP,

About the long time ringing of the moon after an impact, consider the following.

What does Earth have that the Moon does not have?

Large volume of water.
Large volume of loose stones, like sand.
An well filled atmosphere.

Maybe that's enough to explain the difference in dampening, because all that stuff will dampen out a signal pretty quick.

reply to post by Pokoia


Yep, I included that explanation, as described on one of the NASA websites. I believe that has a lot to do with it, but I still don't discount the possibility it is hollow, and that could be increasing the effect too.

Originally posted by Pokoia
Hi OP,

About the long time ringing of the moon after an impact, consider the following.

What does Earth have that the Moon does not have?

Large volume of water.
Large volume of loose stones, like sand.
An well filled atmosphere.

Maybe that's enough to explain the difference in dampening, because all that stuff will dampen out a signal pretty quick.






Great point!
Reminds me last year we discovered silica volcanos on the moon.
How dense is silica? Does it supress vibration?
If the core was silica, would that explain the 60% less density of the moon?

Good place to start. Then go from there.
(sorry on a iPhone can't research efficiently)

reply to post by ChaoticOrder


Hi, thanks for your answer, I posted the following earlier:

The Earth has a plasma core. Not a Nickel Iron core. The Earth and all other larger heavenly bodies are mostly heated by several mini black holes. They are located at the boundary of the plasma and the solid shell.

It was in this thread:
www.abovetopsecret.com...

Looks maybe a bit off topic, but in fact states the same. Both Earth and Moon are hollow, and filled with High pressure plasma.

Originally posted by thepupils
Reminds me last year we discovered silica volcanos on the moon.
How dense is silica? Does it supress vibration?
If the core was silica, would that explain the 60% less density of the moon?

So you are well informed, then I also can assume that you know that the depth of all the craters on the Moon are more or less the same.
Because that is strange, here on Earth, craters originating of a bigger impact tend to be deeper.
So there is silica dust on the moon but it is far less than should be expected.
So I expect this to be the same with the dampening effect of this dust.

Well after using the figures provided by the Moon Fact Sheet which has the volume of Earth and the Moon (reference 4), and the data about the Moons core provided by the new analysis (reference 7), plus info about the Earths core taken from here, it's easy to work out the ratio of the cores (the solid part) volume compared to the total volume of each body, and then see how those results - for both the Earth and Moon - compare to each other.

Earth Total Volume = 108.321 x10^10 km3
Moon Total Volume = 2.1958 x10^10 km3

Earth Core Volume = 0.77568 x10^10 km3
Moon Core Volume = 0.0014137 x10^10 km3

Earth Core Ratio = 0.77568/108.321 = 0.007160938
Moon Core Ratio = 0.0014137/2.1958 = 0.000643820

I'm not sure if I really did that correctly, but it appears that the Moon would have a much smaller core with respect to the volume of the whole Moon, when compared to Earth and its core. But I still don't really know if that can account for the 40% discrepancy in density between the Earth and Moon. Hopefully some one can work it out from here. Though it's probably going to get fairly complex past this point.

Anyway, I'm off to get a bit of sleep. I'll check back in on this thread in a little while.

reply to post by ChaoticOrder


Hi ChaoticOrder,

I hope you know that ALL the descriptions of Earth sub-soil are theory, based on the recorded speed of sound, when earthquakes occurred.
Never there was any real deep core drill, unless you find several KM ( or miles) interesting.

reply to post by ChaoticOrder


No, the Moon is not "hollow"....

.....and although you expended an incredible amount of effort in creating this thread OP....well.....this spoiled it right i the beginning:

The first piece of evidence that suggested the Moon might be hollow appeared in November, 1969, after seismometers were set up on the moon's surface by the astronauts of Apollo 12. As the astronauts took off for Earth, the ascent stage of the lunar module was discarded and it fell onto the moon's surface. It created a tremor that was picked up by the seismometers. NASA found that the Moon was "ringing like a bell" and continued to do so for around an hour.

That phrase ("ringing like a bell") has been so over-used, and mis-understood, ever since.

I saw a recent article about THE SUN, which also describe it as "ringing like a bell"...it's on Wiki.

Surely the SUN is not "hollow"? Is it??


Hate to be the bearer of science....which many seem to think is "bad news" nowadays.......but, the "hollow" Moon idea is very, very wrong.

Check out the latest satellites, the GRAIL mission

They are determining the interior structure of the Moon.

Originally posted by ChaoticOrder
but I don't think this theory is totally crazy; the Moon does have some really odd features, take for instance the "coincidental" math shown in this picture[1]:

Yeah it's kind of crazy. The size of the moon and the size of the sun being similar is a coincidence, but what's that got to do with the hollow moon theory? The other part of that math is basically that there are 12 months in a year...that's not a coincidence. no matter what the orbital period of the moon was the math will come out similarly..where's the coincidence in that? There isn't one that I can see.

The giant impact hypothesis states that the Moon was created out of the debris left over from a collision between the Earth and a Mars-sized body, sometime around 4 Ga (four billion years ago).

So if the Moon is essentially made of the same stuff as Earth, one might wonder why it is so much less dense compared to Earth. Well lets turn to our resident expert Phage to see what he has to say about it. According to him, the Moon is much less dense because its iron core is a lot smaller than that of Earths[6].

The answer may be even simpler than that if you look at the root cause.

What you didn't mention about the giant impact hypothesis is that the impact was believed to be off-center. As a result of this, the dense part of the Earth's core might have remained somewhat intact after the impact. Therefore it would actually be totally illogical for the moon and the Earth to have the same density based on this type of impact. So your asking the question backwards.

The question isn't "why do Earth and the moon have different densities", the question is, "why would they be the same?" Under the giant impact theory, they wouldn't. So there's really no mystery, but you're pretending there is a mystery.

Before we had more evidence of the giant impact hypothesis, we wondered if the moon and the Earth coalesced out of similar material near the same place and same time as the solar system formed. In this scenario, we would expect more similarities in the density. However, this wouldn't necessarily explain the Earth's rotation, which the giant impact hypothesis might explain.

No doubt the moon has hollow areas like the Earth does, probably like hollow lava tubes and what not, as the Earth has hollow structures like caves. But the idea that the moon is a big hollow shell is pretty crazy, for the simple reason that the shell would collapse under its own weight. If you were a civil engineer, you could run the numbers. You can determine the strength of the rock , the mass and the amount of force generated, and so on.

And then there's the surface density problem with the hollow moon theory:

Hollow Moon

Hollow Moon proponents would, however, have to account for the incredible density of the Moon's crust if it were in fact hollow. As gravitational pull is determined by mass, a hollow moon would require an inordinately dense crust to achieve observed gravitational values.

All these "hollow" theories don't make any sense. There's an abundance of data recorded on the moon's crust, mantle, and core.

NASA also did not say "the moon rang like a bell." That's a misrepresentation. NASA said reverberations picked up on seismometers continued longer than expected, which the scientists at the press conference described as "being as surprising as if you struck a bell and it was still ringing an hour later."

That picture makes no sense either.
"Why does the moon appear exactly the same size as the sun in the sky (400 times smaller but 400 times closer) co-incience?"

Does that not make sense? The sun is 93,000,000 miles away as opposed to the moon which is 240,000 miles away. Why would they not appear to be similar sizes from our 2 dimensional perspective? The rest of the math is completely irrelevant. And "400 times smaller?" More like 73,000,000 times smaller.

Riddle me this. Why does every star in the sky appear to be similar size even though they're all scattered throughout the galaxy and are various sizes and distances from one another?

Just food for thought.
Peace

reply to post by Arbitrageur

What you didn't mention about the giant impact hypothesis is that the impact was believed to be off-center. As a result of this, the dense part of the Earth's core might have remained somewhat intact after the impact.

There is a video of the computer simulation of this event.....which occurred VERY early in the Solar System's formation phase:



The varying densities of the two bodies (Earth and Moon) afterwards are well understood, based on this model.

A photo in the OP suggests that without the Moon there would be no seasons, which is entirely incorrect.
We have seasons on Earth due to our axis' inclination and our orbit around the Sun.

reply to post by antirepressant


Good catch.

That picture is full of retardedness...

reply to post by antirepressant

We have seasons on Earth due to our axis' inclination and our orbit around the Sun.

Yes, indeed.....this is a correct statement.

In fact, the axial tilt of this planet, relative to the orbital plane of the entire Solar System, is further evidence of very energetic collisions, in the far distant past....

The Moon is not hollow. It is possible to tell this because when we have had things in orbit around the Moon, how they orbit in the Moon's gravity tells us about the mass of the Moon. We also know the size of the Moon so we can work out the density and see that it is not possible for the Moon to be hollow. The GRAIL mission will further enhance what we already know.

This article will further explain how we determine the interiors of planets and moons.

If the moon is largely hollow, then the shell of the moon under great gravity that has not collapsed would be a major interest to us as to its molecular makeup. We know the crust isn't anything special, but if the mantle was made up of such tinsel strength material missions to the moon after Apollo may not only have been justified, but madly pursued, and the Space Shuttle shelved.

Originally posted by ProudBird
There is a video of the computer simulation of this event.....which occurred VERY early in the Solar System's formation phase:

The varying densities of the two bodies (Earth and Moon) afterwards are well understood, based on this model.

Thanks... the only problem with that video is, for some reason it edits out the rest of the impact, it only shows the initial contact point and then cuts to a later time.

This animation seems to show the impact without the relevant part I was trying to explain being edited out. For best viewing open the video in a new tab and watch full screen in HD:


This one shows how the Earth may have remained mostly intact during and after the impact. As a result of this type of off-center impact, the density differences we observe would be expected, and not a mystery.