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Lava flows on the moon?

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#1 REC

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Posted 23 October 2021 - 11:52 AM

I was reading an article about the latest moon rocks brought back from a China mission. They found that lava continue to flow until 2 billion years ago. How did the moons core get so hot to do this on that "cold rock"? I would think that the lava when it hit surface of the moon with a temperature at 450* in the shade would start to solidify before it got to far? Also the lava is said to flow into the large crater basins of the huge impact craters it has? Sure is a fascinating place!


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#2 sevenofnine

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Posted 23 October 2021 - 03:02 PM

The Science Channel program "How the Universe Works" has some fascinating information on lunar development. We got so much wrong until moon rocks were analysed. There's so much more to be learned. graduate.sml.gif


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#3 maroubra_boy

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Posted 23 October 2021 - 04:20 PM

Lava on the Moon, there's a few parts to this:

1, The way the Moon formed. The Moon is much too large to have been captured by Earth's gravity. The Moon is also the largest satellite to orbit any parent body in proportion to the parent. The only way the Moon could have formed was out of a massive impact between a Mars-sized planet and the primordial Earth. There would have been a colossal amount of material thrown up into space from the explosion. Much of this material would have been left in orbit around the Earth that did not fall back to Earth, and this stuff then slowly started to coalesce into a larger single body in orbit around Earth - the Moon. As with the Earth this coalescing material would have been subjected to pressure and massive friction along with the heat given out be decaying radio isotopes - exactly the same process that would have happened as the Earth formed and the hot magma Earth has is a result of this and the volcanic and tectonic forces we feel as earthquakes. The interior of the Moon would also have been molten in the same way as the formation of Earth, and the exact same volcanic and tectonic forces would have resulted.

2, In the early Moon, the crust would have been very thin and asteroid impacts would have allowed lava to pour out very easily. As the Moon slowly cooled (it is a much smaller body than Earth so heat loss would have been faster), the crust got thicker and with subsequent asteroid impacts the lava flow would have been less. This can be seen in the trio of craters of Ptolemaeus, Alphonsus and Arzachel.
* Ptolemeaus is by far the oldest. It is nearly totally filled with lava, the lunar crust would have been very thin. There are also a few ghost craters within Ptolemeaus - these impacts happened not long after Ptolemeaus itself and lava totally overwhelmed these leaving the ghost of the craters rim.
* Alphonsus formed later on. The crust was thicker and lava flowed less freely filling less of the crater. Its central peak is just visible. Lava flows were not singular with these impacts either. The damaged crater floor is weak and magma pressure would find weak points and further eruptions would happen. In Alphonsus you will see a few distinct dark patches inside it - these are all pyroclastic flows.
* Arzachel is the youngest of the trio, but it still formed while the Moon still had a molten layer below the crust. It had minimal lava flow into it with most of the central peak still visible.

3, The Straight wall is a fault line that formed from tectonic forces of molten magma below the surface. Many other craters also show significant fractures and rilles, many of these also concentric. These fractures are the result of magma pushing up against the flooded crater floor. With these you will notice that these extensive fracture patterns ONLY occur in craters that have been lava filled, and hence are very old structures. Younger craters that are not lava filled never show the same extensive rille patterns. Two such craters are Posidonius and Gassendi.

4, The colouration of the different plains is a further clue to there having been many and multiple lava flows and pyroclastic flows. While there is no air or water to cause erosion on the Moon, weathering still happens on the Moon because of the ferocious solar wind which is chemically very reactive (we see this in the aurora around Earth's poles). The different lava flows have different chemical compositions exactly the same as here on Earth. As a result different chemical compositions will react differently to the solar wind, some getting darker and others staying lighter. The pyroclastic flows I mentioned in Alphonsus are darker than surrounding lava filled floor even though these pyro-flows would be younger. The crater Shickard shows several distinctly shaded areas within its flooded floor, including a single very bright spot called Schickard 1 which is a volcanic dome.

The Moon has long stopped having volcanic activity on its surface. The Chinese information confirmed the age of the last of the surface volcanic activity, which is important. That volcanic activity happened is nothing new and the Chinese mission is not confirming it. It is confirming the end of this activity which was a loose end for us.

The data collected from the seismograhs left by the various Apollo missions was recently reviewed by Japanese scientists using new technology and that allowed for more sensitive interpretation of this data. We had long thought that the core of the Moon was as cold as a door nail. This new review of the Apollo data has shown that the core is around 700°C to 800°C - hot enough to have the core glow red but not hot enough for the rock to be molten like lava. This heat is still there because the surrounding rock is insulating it but it is slowly cooling and ultimately one day it will stone cold. Earth will experience this fate eventually too (if the Sun doesn't exhaust its hydrogen fuel first and becomes a red giant).

The sketches below illustrate points 2, 3 & 4 in order.

Alex.

Attached Thumbnails

  • A-A-P - labels - Copy - Copy.JPG
  • Straight Wall - Copy - Copy.JPG
  • Schickard LR - Copy.JPG

Edited by maroubra_boy, 24 October 2021 - 04:18 PM.

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#4 maroubra_boy

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Posted 23 October 2021 - 05:01 PM

By the way, the crater Copernicus formed long after Arzachel.  Both of these craters are roughly the same size but Copernicus has no lava filled floor.  Its floor is flattened rubble.  Volcanic activity had long ceased on the lunar surface by the time Copernicus was formed.

 

You will notice that there is a range of crater appearances.  Even some small craters are also filled but others have not a trace of being filled.  Understanding this gives one a instant gauge on the relative age of features on the Moon.  If a small crater is filled it will have to be a VERY blooming old impact for lava to flow into it.

 

The Moon is an open story book of its violent history.  It has so much to teach us about planetary formation if we just care to stop and look rather than shake a fist and cuss at it because we can't take pretty pics of galaxies...

 

Alex.


Edited by maroubra_boy, 23 October 2021 - 05:32 PM.

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#5 spkerer

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Posted 23 October 2021 - 07:02 PM

I like the way you worked your sketches into your response.

 

Seriously, I like the way you did that because it both shows some impressive sketching skills and each shows what's being described in the text.  Nicely done.


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#6 BFaucett

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Posted 23 October 2021 - 07:07 PM

I thought this video might be of interest. smile.gif  Click on the image to play the video or on the link to the video below.
 
 

DrBecky-Moon-640x.jpg

 

Video link: https://www.youtube....h?v=At17Klp_pRI

posted to YouTube on Jul 17, 2019

 

How did the Moon form? | 5 things we learnt from the Apollo Moon Landings

Saturday 20th July 2019 is the 50th anniversary of the Apollo 11 Moon landing. Whilst this was one giant leap for mankind, for me it's the scientific legacy of the Apollo missions that are so impressive. So here are 5 things we now know because of the experiments done by the Apollo missions:

 

00:00 - Introduction

01:54 - the distance to the Moon

04:08 - the structure inside the Moon

05:51 - what the solar wind is made of

08:43 - what the Moon is made of

12:33 - how the Moon was formed

 

In particular, all the results from Apollo built up to overhaul our thinking of how the Moon formed.

 

YouTube channel: Dr. Becky

Dr. Becky Smethurst is an astrophysicist at the University of Oxford.

University of Oxford: https://www.physics....eople/smethurst

Personal website: https://rebeccasmethurst.co.uk/

 

 
"Rebecca Smethurst is a British astrophysicist, author, and YouTuber who is a Junior Research Fellow at the University of Oxford. She was the recipient of the 2020 Caroline Herschel Prize Lectureship awarded by the Royal Astronomical Society as well as the 2020 Mary Somerville Medal and Prize awarded by the Institute of Physics. As a researcher, Smethurst studies the role that supermassive black holes play in inhibiting different types of galaxies from forming stars. She is a member of the Galaxy Zoo collaboration run by her doctoral advisor Chris Lintott. Smethurst hosts her own YouTube channel called Dr. Becky where she posts science communication videos related to astronomy research and amateur astronomy. She has also written a popular science book titled Space: 10 Things You Should Know."
https://en.wikipedia...Becky_Smethurst
 
Cheers! Bob F. smile.gif


Edited by BFaucett, 23 October 2021 - 07:26 PM.

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#7 maroubra_boy

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Posted 23 October 2021 - 09:49 PM

The samples that the Apollo missions brought back are invaluable! <--- This is the greatest understatement I have ever made!

The training that the Astronauts had included visits to very specific geologic formations here on Earth so that they had hands-on experience in identifying not only minerals but also strata formations which give clues to mineral deposits. Their training also included visits to the atomic bombing range in New Mexico - it may sound crazy but atomic blasts were the way that the riddle of the origin of impact craters here on Earth was answered. Other than giant asteroids exploding on impact, it is only nuclear blasts that form very specific and unique mineral structures. Surface nuclear blasts also displace the ground in the same way that an exploding asteroid does, and because nuclear blast sites are fresh compared to say the Arizona crater which is severely affected by erosion and weathering, these sites provide the closest analogues to lunar craters because there is no erosion and far less weathering than on Earth.

From the samples brought back, the signature minerals that linked the origin of the Moon to a colossal impact here on Earth as the source of the Moon's origin was demonstrated, in particular samples brought back by Apollo 15. So, yeah, my description of the formation of the Moon stems directly from what the Apollo brought back.

Spkerer, since I started sketching the Moon as one of the things that floats my astro boat has been researching the area that I just spent two to three hours putting down on paper. I do like to use my sketches to illustrate points because I feel that it makes it more intimate the information I have provided and use it as evidence and understanding of my research.

Volcanic features are one aspect that VERY FEW resources actually ever mention and certainly next to never are displayed in the same level of detail as blasted craters - as if craters and a few miserable rilles are all that occur on the Moon's surface... Think you know the Moon? Mate, if all you think about are craters and a few rilles then you have no idea what the Moon has been showing us each and every month for the last 4 billion years. 4 billion years worth of history, terrifying history, is on display each and every month bombdrop.gif

Below is a screenshot of the area around Copernicus that I mentioned in my first post here. Volcanic domes and vents are identified by the numerical suffix. You will note that there are absolutely no volcanic artefacts within or immediately around Copernicus. I have only ever seen this level of detail in Virtual Moon Atlas:

https://ap-i.net/avl/en/start

Alex.

Attached Thumbnails

  • Copernicus & surrounds - LR.jpg

Edited by maroubra_boy, 24 October 2021 - 05:43 AM.

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#8 REC

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Posted 24 October 2021 - 12:23 PM

Lava on the Moon, there's a few parts to this:

 

1,  The way the Moon formed.  The Moon is much too large to have been captured by Earth's gravity.  The Moon is also the largest satellite to orbit any parent body in proportion to the parent.  The only way the Moon could have formed was out of a massive impact between a Mars-sized planet and the primordial Earth.  There would have been a colossal amount of material thrown up into space from the explosion.  Much of this material would have left in orbit around the Earth and this stuff then slowly started to coalesce into a larger single body in orbit around Earth - the Moon.  As with the Earth this coalescing material would have been subjected to pressure and massive friction along with the heat given out be decaying radio isotopes - exactly the same process that would have happened as the Earth formed and the hot magma Earth has is a result of this and the volcanic and tectonic forces we feel as earthquakes.  The interior of the Moon would also have been molten in the same way as the formation of Earth, and the exact same volcanic and tectonic forces would have resulted.

 

2, In the early Moon, the crust would have been very thin and asteroid impacts would have allowed lava to pour out very easily.  As the Moon slowly cooled (it is a much smaller body than Earth so heat loss would have been faster), the crust got thicker and with subsequent asteroid impacts the lava flow would have been less.  This can be seen in the trio of craters of Ptolemaeus, Alphonsus and Arzachel.

*  Ptolemeaus is by far the oldest.  It is nearly totally filled with lava, the lunar crust would have been very thin.  There are also a few ghost craters within Ptolemeaus - these impacts happened not long after Ptolemeaus itself and lava totally overwhelmed these leaving the ghost of the craters rim.

*  Alphonsus formed later on.  The crust was thicker and lava flowed less freely filling less of the crater.  Its central peak is just visible.  Lava flows were not singular with these impacts either.  The damaged crater floor is weak and magma pressure would find weak points and further eruptions would happen.  In Alphonsus you will see a few distinct dark patches inside it - these are all pyroclastic flows.

*  Arzachel is the youngest of the trio, but it still formed while the Moon still had a molten layer below the crust.  It had minimal lava flow into it with most of the central peak still visible.

 

3,  The Straight wall is a fault line that formed from tectonic forces of molten magma below the surface.  Many other craters also show significant fractures and rilles, many of these also concentric.  These fractures are the result of magma pushing up against the flooded crater floor.  With these you will notice that these extensive fracture patterns ONLY occur in craters that have been lava filled, and hence are very old structures.  Younger craters that are not lava filled never show the same extensive rille patterns.  Two such craters are Posidonius and Gassendi.

 

4,  The colouration of the different plains is a further clue to there having been many and multiple lava flows and pyroclastic flows.  While there is no air or water to cause erosion on the Moon, weathering still happens on the Moon because of the ferocious solar wind which is chemically very reactive (we see this in the aurora around Earth's poles.  The different lava flows have different chemical compositions exactly the same as here on Earth.  As a result different chemical compositions will react differently to the solar wind, some getting darker and others staying lighter.  The pyroclastic flows I mentioned in Alphonsus are darker than surrounding lava filled floor even though these pyro-flows would be younger.  The crater Shickard shows several distinctly shaded areas within its flooded floor, including a single very bright spot called Schickard 1 which is a volcanic dome.

 

The Moon has long stopped having volcanic activity on its surface.  The Chinese information confirmed the age of the last of the surface volcanic activity, which is important.  That volcanic activity happened is nothing new and the Chinese mission is not confirming it.  It is confirming the end of this activity which was a loose end for us.

 

The data collected from the seismograhs left by the various Apollo missions was recently reviewed by Japanese scientists using new technology and that allowed for more sensitive interpretation of this data.  We had long thought that the core of the Moon was as cold as a door nail.  This new review of the Apollo data has shown that the core is around 700°C to 800°C - hot enough to have the core glow red but not hot enough for the rock to be molten like lava.  This heat is still there because the surrounding rock is insulating it but it is slowly cooling and ultimately one day it will stone cold.  Earth will experience this fate eventually too (if the Sun doesn't exhaust its hydrogen fuel first and becomes a red giant).

 

The sketches below illustrate points 2, 3 & 4 in order.

 

Alex.

Thanks for that in depth explanation of the moon. Lot's to study from your story, which is excellent!


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