Moon Mysteries.

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Number 14 is a great point.

'The sun’s diameter is about 400 times larger than that of the moon – and the sun is also about 400 times farther from Earth. So the sun and moon appear nearly the same size as seen from Earth. What are the odds?'
The moon is actually accelerating out of Earth orbit. This means that billions of years ago it was much closer and therefore had an apparent diameter much larger than that of the Sun and in billions of years will have an apparent diameter much smaller than the Sun. It just so happens that we are looking at it it at a point in time when it is apparently the same diameter.

But let's not let that get in the way of a good conspiracy.
 
Threads like this bring out the coffee table philosophers and google copy and paste scientists. We know very little because we aren't capable of knowing all. -_-
 
Threads like this bring out the coffee table philosophers and google copy and paste scientists. We know very little because we aren't capable of knowing everything. -_-

Threads like this bring out the coffee table philosophers and google copy and paste scientists. We know very little because we aren't capable of knowing everything. -_-

Threads like this bring out the coffee table philosophers and google copy and paste scientists. We know very little because we aren't capable of knowing everything. -_-
 
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I agree debate is good, and that science doesn't have answers for everything. HOWEVER, If one side is misrepresenting stuff I tend to prefer to point it out. Ie., the moon is actually a pretty dense satellite - the exact opposite of what the article states. Does that make all but one of the other moons in the solar system alien spacecraft too?

Yes it's quite dense but not as dense as it should be, i.e like us on Earth. The Moon’s mean density is 3.34 gm/cm3 (3.34 times an equal volume of water) whereas the Earth’s is 5.5. Earthquakes only propagate for a few minutes here, but moonquakes can last for hours? Explanation please.

"Rings like a bell" NASA says. http://science.nasa.gov/science-news/science-at-nasa/2006/15mar_moonquakes/
 
Yes it's quite dense but not as dense as it should be, i.e like us on Earth. The Moon’s mean density is 3.34 gm/cm3 (3.34 times an equal volume of water) whereas the Earth’s is 5.5. Earthquakes only propagate for a few minutes here, but moonquakes can last for hours? Explanation please.

"Rings like a bell" NASA says. http://science.nasa.gov/science-news/science-at-nasa/2006/15mar_moonquakes/

No mystery here mate. The Earth's MEAN density of Earth is indeed circa 5 gm/cm3. That's because of it's relatively large iron/nickel core, surrounded a largely basaltic mantle. The moon possesses a much smaller iron core by comparison, it consists largely of basaltic type material hence the lower MEAN density. The absence of a large iron/nickel core in the moon is due to the impact of Rhea and the proto-Earth where the two cores amalgamated and settled into the large core present in the Earth today. Pretty straight forward really.

As for the Earthquakes, i'd guess it would be something to do with the fact that the p-waves generated by Earthquakes are refracted as they enter a liquid (and the Earth's core is surrounded by a substantial molten outer core.....which gives us our magnetic field effectively) whilst the s-waves cannot pass though a liquid at all. Because the moon has a tiny liquid outer core (if indeed there is anything molten at all) and it is tectonically dead (i.e there is no movement or turnover of mantle) there is no dampening effect that a liquid, molten material provides to a shock force - that is an earthquake.

I'd imagine it would be like hitting a bowling ball and then a water balloon with a hammer. Which one would make your hand vibrate like fuck.
 
No mystery here mate. The Earth's MEAN density of Earth is indeed circa 5 gm/cm3. That's because of it's relatively large iron/nickel core, surrounded a largely basaltic mantle. The moon possesses a much smaller iron core by comparison, it consists largely of basaltic type material hence the lower MEAN density. The absence of a large iron/nickel core in the moon is due to the impact of Rhea and the proto-Earth where the two cores amalgamated and settled into the large core present in the Earth today. Pretty straight forward really.

As for the Earthquakes, i'd guess it would be something to do with the fact that the p-waves generated by Earthquakes are refracted as they enter a liquid (and the Earth's core is surrounded by a substantial molten outer core.....which gives us our magnetic field effectively) whilst the s-waves cannot pass though a liquid at all. Because the moon has a tiny liquid outer core (if indeed there is anything molten at all) and it is tectonically dead (i.e there is no movement or turnover of mantle) there is no dampening effect that a liquid, molten material provides to a shock force - that is an earthquake.

I'd imagine it would be like hitting a bowling ball and then a water balloon with a hammer. Which one would make your hand vibrate like fuck.

Saved me typing that mate, thanks.
 
Strange thread. I'm in the third year of an astrobiology degree - last year was primarily focussed on planetary formation and the origins of the solar system. Not really nay debate at all about he moon formation from what I can see. The isotopic ratios of oxygen fall perfectly on what's called the terrestrial fractionation line (TFL) showing that they match the ratios of the baseline Standard Mean Ocean Water (SMOW).

In other words, the ratios of O16, O17 and O18 in lunar rock samples originated from the same unique place that the ratios of O16, O17 and O18 did on Earth. (Samples from Mars and various meteorites have isotopic ratios which are parallel to the TFL showing that they started with a different initial mixture of oxygen isotopes).

The point about the lack of an iron core being somehow questionable is ludicrous. When Rhea collided with the proto-Earth , it's iron core amalgamated with Earth's iron core (due to density and gravity essentially) whilst the volatiles were all ejected which eventually coalesced into the Moon.

Oh and the Moon's craters are simply a result of the late-heavy bombardment went it was pulverised by rocks the size of skyscrapers for a few million years. No atmosphere to slow them down so it was the equivalent of a few trillion nuclear explosions detonating every few days :lol:

I think this video explains visually what you're trying to say.

Your statement is correct, the isotopes of both the moon and Earth have shared origins. But this only increases the confusion, so either the moon came from Earth's imaginary surface mantle or it originated independently from the same material. So if it came from our mantle, I can agree with your Iron core and volatile elements suggestion, but what of lack of refractory elements and abundance of other heavy metals in the moons crust. These should have (using the giant impactor model) coalesced very differently to what we can see. It doesn't explain the angular momentum of the moon's orbit either.

Here's what wiki says about other deficiencies of the impactor model. http://en.wikipedia.org/wiki/Giant_impact_hypothesis

This lunar origin hypothesis has some difficulties that have yet to be fully resolved. For example, the giant impact hypothesis implies that a surface magma ocean would have formed following the impact. Yet there is no evidence that the Earth ever had such a magma ocean and it is likely there exists material that has never been processed by a magma ocean.[28]

Composition
There are a number of compositional inconsistencies that need to be addressed.
  • The ratios of the Moon's volatile elements are not explained by the giant impact hypothesis. If the giant impact hypothesis is correct, they must be due to some other cause.[28]
  • The presence of volatiles such as water trapped in lunar basalts is more difficult to explain if the Moon was caused by an impact that would entail a catastrophic heating event.[29]
  • The iron oxide (FeO) content (13%) of the Moon, which is intermediate between Mars (18%) and the terrestrial mantle (8%), rules out most of the source of the proto-lunar material from the Earth's mantle.[30]
  • If the bulk of the proto-lunar material had come from the impactor, the Moon should be enriched in siderophilic elements, when, in fact, it is deficient in those.[31]
  • The Moon's oxygen isotopic ratios are essentially identical to those of Earth.[6] Oxygen isotopic ratios, which may be measured very precisely, yield a unique and distinct signature for each solar system body.[32] If Theia had been a separate proto-planet, it probably would have had a different oxygen isotopic signature than Earth, as would the ejected mixed material.[33]
  • The Moon's titanium isotope ratio (50Ti/47Ti) appears so close to the Earth's (within 4 ppm), that little if any of the colliding body's mass could likely have been part of the Moon.[34][35]

Back to your post. Do we know where this late heavy bombardment LHB came from? The planet that should be in between Mars and Jupiter and where the Asteroid belt is now perhaps? We still can't explain why the orbit of these asteroids suddenly hit the moon-earth system head on. So early in the solar system formation, we had planets like Saturn, Jupiter moving around willy nilly causing havoc in the inner part solar system. I can understand that.

I take your point on the LHB and how it can explain away some of the anomalies but can it explain why the crater depth on the moon is a max of 1-2 miles? Regardless of diameter?

Threads like this bring out the coffee table philosophers and google copy and paste scientists. We know very little because we aren't capable of knowing all. -_-

Nowt wrong with either, I do both. Not all of us can be full on hippies and work in CalTech or MIT like you marra.
 
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