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Old 11-01-2017, 11:09 PM
 
Location: PRC
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What did it find out about the interior of the Moon?

It would seem looking at this Insight mission page, which is fairly recent, the Moon has a liquid centre similar to the Earth and Mars, yet when they crashed those spacecraft pieces into the Moon, it reverberated for ages.

I seem to remember liquid dampens vibrations doesn't it? However, I believe the phrase they used was it rang like a bell. OK, so this probably means there are different rocks and it has a different composition, but normally this kind of prolonged vibration might suggest a hollow or semi-hollow interior.

So what is the official explanation for this continued vibration or ringing after the spacecraft crashed into the Moon?
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Old 11-03-2017, 03:57 PM
 
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When I posted the thread about the cavern on the Moon discovered by the Japanese Space Agency, I wondered about whether the Moon was geologically dead, or whether it experienced moon-quakes.

Turns out that the gravitational pull of the Earth constantly compresses the Moon, but that compression isn't constant. The result is that there are such things as moon-quakes. The same article that talked about the cause of moon-quakes also pointed out that they last much longer than earthquakes, the reason being that the Earth's oceans dampen earthquake aftershocks, but the Moon has no such natural dampener. It's probably why they used the phrase 'rang like a bell' in your linked article.
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Old 03-12-2018, 02:07 AM
 
Location: PRC
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I reckon NASA wanted to confirm that the Moon was hollow when they crashed the spacecrafts into the Moon.

The Earth-Moon system is about 4.5 billion years old. The Moon was formed when it broke off from the Earth. The basic components should be the same for both of them. Oldest Earth rocks are roughly 3.5 billion years old, yet some of the Moon rocks have been dated at over 5 billion years old. If the Moon was formed from the Earth then how come they are different ages?

Iron is quite rare on the Moon but there is lots of it here on Earth. If theye came from the same place, they would be roughly similar.

Now, about the hollowness of the Moon.
Earth has a mean density of 5.5g per cc, the Moon has a mean density of only 3.3g per cc. If they were formed at the same time, then they should have similar mean densities. The difference in densities suggests that the Moon does not have a solid core like the Earth does.

Natural made Moons are SOLID.

so, it seems, THIS is why the Moon rang like a bell for nearly an hour when NASA crashed its spacecraft into the surface.
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Old 03-12-2018, 12:28 PM
 
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Quote:
Originally Posted by ocpaul20 View Post
I reckon NASA wanted to confirm that the Moon was hollow when they crashed the spacecrafts into the Moon.

The Earth-Moon system is about 4.5 billion years old. The Moon was formed when it broke off from the Earth. The basic components should be the same for both of them. Oldest Earth rocks are roughly 3.5 billion years old, yet some of the Moon rocks have been dated at over 5 billion years old. If the Moon was formed from the Earth then how come they are different ages?

Iron is quite rare on the Moon but there is lots of it here on Earth. If theye came from the same place, they would be roughly similar.
Actually, the oldest rocks on earth have been dated at over 4 billion years old. Zircon crystals from Australia have been confirmed at 4.375 billion years, give or take a few million years.
''Well, scientists just took one of geology's biggest controversies and shrunk it down to atomic size. By zapping single atoms of lead in a tiny zircon crystal from Australia, researchers have confirmed the crystal is the oldest rock fragment ever found on Earth — 4.375 billion years old, plus or minus 6 million years.''
https://www.livescience.com/43584-ea...ls-zircon.html
The oldest lunar rocks are similarly dated to about 4.5 billion years and so match the age of the earth.


Oldest Moon Rocks
''The Apollo missions sampled ancient lunar crustal rocks. These rocks are about 4.5 billion
years old, indicating that parts of the Moon's crust solidified soon after the Moon formed.''
Photographs courtesy of NASA Johnson Space Center.

https://www.lpi.usra.edu/education/t.../slide_15.html

I'm not sure where you got the idea that moon rocks are older than the moon itself.



Quote:
Now, about the hollowness of the Moon.
Earth has a mean density of 5.5g per cc, the Moon has a mean density of only 3.3g per cc. If they were formed at the same time, then they should have similar mean densities. The difference in densities suggests that the Moon does not have a solid core like the Earth does.

Natural made Moons are SOLID.

so, it seems, THIS is why the Moon rang like a bell for nearly an hour when NASA crashed its spacecraft into the surface.
The reason the moon rang like a bell has been explained as follows by Dr. Clive R. Neal who is a professor in the Department of Civil Engineering & Geological Sciences at the University of Notre Dame, Indiana.
''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.''

https://www.nasa.gov/exploration/hom...oonquakes.html
So. . . no. The best explanation why the moon rang is not because it is an artificial moon created by aliens. It is a natural moon. A new model of how the moon was formed was recently advanced.
The moon formed inside a vaporized Earth synestia

Date:
February 28, 2018
Source:
University of California - Davis

''A new explanation for the Moon's origin has it forming inside the Earth when our planet was a seething, spinning cloud of vaporized rock, called a synestia. The new model led by researchers at the University of California, Davis and Harvard University resolves several problems in lunar formation and is published Feb. 28 in the Journal of Geophysical Research -- Planets.''

''An advantage of the new model, Lock said, is that there are multiple ways to form a suitable synestia -- it doesn't have to rely on a collision with the right sized object happening in exactly the right way.''

Read the details here: https://www.sciencedaily.com/release...0228103238.htm

Last edited by Mike555; 03-12-2018 at 12:46 PM..
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Old 03-12-2018, 10:01 PM
 
Location: PRC
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Quote:
Originally Posted by Mike555
I'm not sure where you got the idea that moon rocks are older than the moon itself.
Did I? Where did I say that?

I thought I said that the Moon was older than the Earth and the density differences showed it could possibly be hollow inside.

So, to address this issue, what other explanations are there for the Earth/Moon different density?.

Last edited by ocpaul20; 03-12-2018 at 10:48 PM.. Reason: typo
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Old 03-13-2018, 12:54 AM
 
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Quote:
Originally Posted by ocpaul20 View Post
Did I? Where did I say that?

I thought I said that the Moon was older than the Earth and the density differences showed it could possibly be hollow inside.

So, to address this issue, what other explanations are there for the Earth/Moon different density?.
In post #3 you said, ''the Earth-Moon system is about 4.5 billion years old.'' Then you said, ''yet some of the Moon rocks have been dated at over 5 billion years old.''

Perhaps that wasn't your intended meaning, but it came out as moon rocks being older than the moon.

You also said, ''The Moon was formed when it broke off from the Earth.'' If the moon was formed when it 'broke off from the earth then how can the moon be older than the earth? And to top it off you then implied that the moon is not a natural moon. If the moon 'broke off' from the earth then how can it not be a natural moon?

You might want to give more thought to what you want to say before posting.

According to the source I looked at, https://www.reddit.com/r/askscience/...arths_density/, the moon's density is 3.34 g/cm3 (the 3 should be a superscript but I can't format it that way). The earth's density is 5.52 g/cm3.

The difference in density apparently is because the moon has a comparatively smaller core than the earth which has a very large and dense core. Also, if the moon was formed as the result of the earth being impacted by a large object, the heavier elements would have fallen back to the earth while the lighter elements would have formed the moon. Since the earth and the moon are both rocky objects, the earth, being larger, would have compressed its material more densely than the moon did.

Last edited by Mike555; 03-13-2018 at 01:27 AM..
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Old 03-13-2018, 03:40 PM
 
Location: Heart of Dixie
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Quote:
Originally Posted by Mike555 View Post
...the moon's density is 3.34 g/cm³ (the 3 should be a superscript but I can't format it that way). The earth's density is 5.52 g/cm³...
There ya go.
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Old 03-13-2018, 05:59 PM
 
22,794 posts, read 17,268,975 times
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Quote:
Originally Posted by Dirt Grinder View Post
There ya go.
How did you do that? When I try to copy and paste a number with a superscript it just appears as a regular number.

Oh, there's such a thing as a superscript generator. I had no idea. 5⁵ I learned something new. Thanks for giving me the incentive to look.

https://lingojam.com/TinyTextGenerator

Last edited by Mike555; 03-13-2018 at 06:32 PM..
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Old 03-14-2018, 04:08 AM
 
Location: PRC
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Quote:
The difference in density apparently is because the moon has a comparatively smaller core than the earth which has a very large and dense core. Also, if the moon was formed as the result of the earth being impacted by a large object, the heavier elements would have fallen back to the earth while the lighter elements would have formed the moon. Since the earth and the moon are both rocky objects, the earth, being larger, would have compressed its material more densely than the moon did.
We are not talking about a little nuclear bomb explosion here, we are talking about one planet being impacted by a HUGE object. Large enough to remove a large portion of Earth's mass. I dont think any 'heavier elements' would have fallen back to Earth. A "smaller core" could actually be no core as well.

OK Well, doing a bit more research on this I found out that the age of Moon rocks is disputed. Mainly because a large number of the Moon rocks were scientifically analysed and there was a HUGE range of dates as a result. From less than 1 billion to more than 8 billion years old. So I guess science does not have a concensus as to the Age of the Moon.

The Verge reports a fairly new study which uses zircon to date the rocks but it is a destructive test and needs to dissolve the zircon in acid in order to measure the amounts present. There are also some assumptions which other scientists point out have been made in the method so it is not ideal.

At this stage it seems, everyone thinks the Moon was formed by ejected material from the Earth when it was forming and cannot be something which was captured later on.
Quote:
the planetesimal accretion hypothesis in which the origin of the Moon was intimately linked to the early evolution of the Earth through gigantic collisions between proto-planets.
Link to quote

A presentation on rock dating is here

Age of Sun via chemical composition and known rate of fusion: about 5 Ga
Oldest Earth rock: 3.98 Ga
Age of oldest Moon Rocks: 4.2 Ga
Age of Meteorites: 4.5 Ga
Ga = billion years
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Old 03-19-2018, 03:31 AM
 
3,426 posts, read 2,791,710 times
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Quote:
Originally Posted by ocpaul20 View Post
I reckon NASA wanted to confirm that the Moon was hollow when they crashed the spacecrafts into the Moon.

The Earth-Moon system is about 4.5 billion years old. The Moon was formed when it broke off from the Earth. The basic components should be the same for both of them. Oldest Earth rocks are roughly 3.5 billion years old, yet some of the Moon rocks have been dated at over 5 billion years old. If the Moon was formed from the Earth then how come they are different ages?

Iron is quite rare on the Moon but there is lots of it here on Earth. If theye came from the same place, they would be roughly similar.

Now, about the hollowness of the Moon.
Earth has a mean density of 5.5g per cc, the Moon has a mean density of only 3.3g per cc. If they were formed at the same time, then they should have similar mean densities. The difference in densities suggests that the Moon does not have a solid core like the Earth does.

Natural made Moons are SOLID.

so, it seems, THIS is why the Moon rang like a bell for nearly an hour when NASA crashed its spacecraft into the surface.
The Moon did not break off from Earth. The collision between Earth and a Mars-sized body created a torus of molten and vaporized rock. As it spun, the outer portion of the torus rotated faster than the inner portion but never completely differentiated chemically from the inner portion, which is why the isotopic ratios are almost exactly the same for the Moon and Earth. Eventually, Earth formed in the slower moving portion while the Moon formed in the faster moving outer portion. This scenario better explains all the data that we have about the Earth-Moon system.

https://www.extremetech.com/extreme/...ation-synestia

Moreover, there have been found rocks much older than 3.5 billion years on Earth. The oldest confirmed fragment of Earth found to date is 4.4 billion years old. The oldest rock found on the Moon was brought back by Apollo 16 and is 4.46 billion years old. The difference in densities of the Moon and Earth is due to the fact that Earth received the bulk of the heavy metals that existed in the torus when the system was formed (which now sits in the core). The bulk of the moon is composed of mafic and ultra mafic rock similar to Earth's mantle. Only Earth's inner core is solid, while its outer core is not.
The Moon has a solid core, a molten outer core, like Earth, and a zone of partial melt:



https://www.nasa.gov/topics/moonmars...unar_core.html

Last edited by orogenicman; 03-19-2018 at 03:45 AM..
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