Re: [asa] moon dust

I should point out that the argument is even more compelling on Mars because there you have volcanoes, river networks, dry ocean beds, and layer upon layer upon layer of sediment in the canyons and craters where lakes used to be. There was never any tectonics to destroy the record of the past. The geological history is long and varied, and can't be explained by Noah's flood since Noah didn't live on Mars. Ironically, the earliest geological epoch on Mars is called the Noachian, a reference to Noah, because that is when Mars was wet.
 
Phil Metzger
 
 
 
-----Original Message-----
From: tandyland@earthlink.net
To: philtill@aol.com
Sent: Fri, 12 Jan 2007 6:38 PM
Subject: RE: [asa] moon dust

>>I like pointing to the Moon and Mars to counter some of the wacky YEC claims, because those bodies aren't supposed to have had a global flood and so you can't appeal to amazingly coincidental splashes of sediments and fossils and isotopes to fall together in the flood and form the entire geologic column. Of course, you can't really appeal to that anyhow, but it is just more obvious that you can't do it on the Moon where there was no flood.>>
 
This is an excellent point. I've read about the radioactive isotope dating of the moon rocks being roughly the same (4 billion years) as that of earth rocks and meteorites. If recent YEC arguments about the global flood speeding up radioactive decay rates by several orders of magnitude, then why would the moon have the same age rocks?
 
Are you saying that there are recognizable sediment layers on the moon, due to the processes you outlined, which can be dated through successive layers through a relatively predictable sequence of dates back to multiple million/billion years? (Again, what about these sediment layers, if no global flood?) Where can more of this data be found, to understand this kind of moon surface dating sequence in detail?
 
 
Jon Tandy
 
-----Original Message-----
From: asa-owner@lists.calvin.edu [mailto:asa-owner@lists.calvin.edu] On Behalf Of philtill@aol.com
Sent: Friday, January 12, 2007 4:41 PM
To: pleuronaia@gmail.com; asa@calvin.edu
Subject: Re: [asa] moon dust

Hi David,
 
I think the source you found here is misleading. Not only will it not answer the YEC's silly claim (because it misses their point), but it also confuses the science and thus misses a much better argument that can be made for the oldness of the Moon.
 
We distinguish between "dust" and "soil" in the regolith. Soil does include the "dust-sized" particles (we call them silt- or clay-sized particles when they are mixed in the soil, or we call them the "fines fraction"), but it also inludes sand-sized particles and perhaps even gravel in the loose definition of soil. Regolith includes even more than "soil" does because it also includes the gravel, stones, boulders, and even large but busted-out blocks from the bedrock. When the paragraph below describes the astronauts hammering the core tube 70 cm into the soil, that wasn't dust they were hammering it into. It was regolith, or better it was "soil" (not passign through the rocks or boulders that would have blocked the tube).
 
There actually is a very small dust layer lying on top of the regolith and it is perhaps a centimeter deep or so. It is segregated out from the regolith because of the unique electrostatic processes on the Moon. Without an atmosphere to mediate electrostatic charge, particles can become highly charge-up in the strong UV light of the sun (due to the photoelectric effect) and then they can remain charged for long times. Then, as the overall region of soil becomes positively charged, they levitate away from one another or even fly up into the sky like popcorn. The astronauts reported seeing geysers of dust shooting up above the horizon where the day/night terminator line was approaching them. Then, the dust falls back down onto the top layer of the regolith. The bigger particles and boulders cannot do this, of course, so it tends to segregate out the silt- or clay-sized particles. By this process, a true dust layer exists on top of the soil, which is distinct from the soi
 l (or more generally from the regolith) that is beneath it. This dust layer is very thin, which gives rise to the wacky YEC claims.
 
Their claim arose from the influx of dust from space onto the earth. The YEC's weren't talking about the soil or regolith on the Moon. They were talking about the very fine-particled dust layer falling on top of it from space and building up. (That's why the paragraph quoted below misses their point.) Supposedly if you extrapolate this influx from space for four billion years then you get a huge depth of dust on the Moon, and without any lunar oceans to convert the fines into mudstone it should still be lying there on the surface, right? Well, wrong. For one thing, I think the influx measurement they based this on was inaccurate and has since been corrected. But more to the point, this is a typical "one-sided" equation that the YEC's are famous for presenting. There are actually processes beside oceans and mudstone that convert fine particles into something different.
 
The Moon is constantly bombarded by micrometeorites that on Earth would have been filtered out by the Earth's atmosphere. These micrometeorites tend to break larger particles into smaller ones (comminution) and also create glass splatters from the molten material that then hardens and glues smaller particles together into larger ones (agglutination). This produces a characteristic particle size distribution in the soil. In fact, you can date the age of the soil in any given area by looking at the fraction of agglutinates, as well as many other dating methods. When a larger asteroid or meteor strikes the Moon, it might excavate deeply enough into the regolith to reach bedrock, which it then busts up and throws out as an ejecta blanket. Thus, it has deepened the regolith and also created fresh soil. This immature soil does not have any agglutinates and it has a particle size distribution that is much coarser than aged soil (fewer fi nes). You can estimate how many millio
 ns of years it has been lying there by how many agglutinates have built up in it and also by how many fines have been created through comminution. In fact, you can see layering in the lunar soil and these layers are varying in maturity age. That is because one ejecta blanket is thrown out over another, so the soil tends to get more mature (more agglutinates, more fines) the deeper you go. You can also go to the blanket of a young crater (dated independently by [1] its blanket being on top of all the others, [2] by the number of cosmic ray tracks in the particles, and [3] by the rim of the crater not being eroded through smaller imact events), and see how it has indeed very few agglutinates and is very coarse. This produces an independent verification of an old earth, in addition to all the other methods, and of course it agrees with the overall paradigm that we see everywhere in nature.
 
Furthermore, in addition to the agglutination process that converts dust into larger particles, the micrometeorite "gardening" process also mixes particles, so that dust lying on the surface can get buried as the soil is overturned. There are well-accepted rates at how fast the soil is overturned to a particular depth on the Moon, based on the influx rate of different size meteorites and micrometeorites.
 
(Of course, reality is very complicated and so there is a lot more in lunar soil to take into consideration beyond this, but this gives a basic sketch of some of the key concepts.)
 
I like pointing to the Moon and Mars to counter some of the wacky YEC claims, because those bodies aren't supposed to have had a global flood and so you can't appeal to amazingly coincidental splashes of sediments and fossils and isotopes to fall together in the flood and form the entire geologic column. Of course, you can't really appeal to that anyhow, but it is just more obvious that you can't do it on the Moon where there was no flood.
 
By the way, I have studied every single report prior to the Surveyor and Apollo landings on the Moon, and I have yet to see one that says NASA expected 10 feet of dust or that the legs of the landers were going to be 10 feet long. Every single report I have seen had predicted 2 or 3 cm of dust, which is exactly what we found. That's because the lunar scientists weren't working with one-sided equations. I don't know where this urban legend came from, that says NASA predicted deep dust. I think there may have been perhaps **one** oddball paper way back (which I have yet to find) that said something to that effect. But in general, NASA **never** believed there would be thick dust on the Moon.
 
Now there has been some recent discussion that there **might** actually be thick dust inside the permanently shadowed craters near the lunar poles. That is because (as mentioned above) the UV transport process can cause dust-sized particles in sunlight to fly up, and if they fall back down into a permanently-shadowed crater then they will never become charged up by UV again and so they can never again come out. However, impact processes can throw them out and convert them to soil and overturn the soil to mix them in, and so lest we make the mistake of a one-sided equation you must compare the rates of those processes against the rate of the dust falling in by the UV transport, and so the dust might be thicker than 2 or 3 cm but by how much??? I have not seen that calculation yet, but we probably will in the next year or two since we are seriously considering one of the poles as the site of the next lander.
 
God bless!
Phil Metzger
 
 
 
 
 
 
-----Original Message-----
From: pleuronaia@gmail.com
To: asa@calvin.edu
Sent: Fri, 12 Jan 2007 3:33 PM
Subject: [asa] moon dust

Since the moon dust argument is so popular, I thought it might be
helpful to post what I recently found in tracking down details.
 
The material on the moon's surface (or other planets) above the solid
rock is called regolith. As on Earth, it includes smaller and larger
pieces and is more solidly compacted below the surface. The claim
that the dust layer on the moon is very thin was based on a newspaper
photo of astronaut footprints. In reality, the astronauts were able
to hammer a hand core in 70 cm and mechanical drills went in over a
meter without reaching solid rock. Based on measurements by
seismometers and observation of shallow craters (no old small craters
are visible; young small craters appear to only penetrate the
regolith), average depth of regolith is estimated at about 4 m. Thus,
the claim that the layer is only a few cm or inches is off by a
similar order of magnitude to some of the high estimates for dust
layer thickness that are popularly cited in young-earth arguments.
(The presence of other, lower estimates for expected regolith
thickness is not usually mentioned.)
 
If you step on dust, on Earth or the Moon, you don't sink to solid rock.
 
-- Dr. David Campbell
425 Scientific Collections
University of Alabama
"I think of my happy condition, surrounded by acres of clams"
 
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Received on Fri Jan 12 20:10:12 2007