Lunar Florescent sources

[Drifter]

I looked at that photo earlier and thought that shadow on the eastern side is showing a rim far higher than expected from objects fragmented from such a low angle from Messier …. what happened to the Zone of Avoidance? …. it suddenly went missing from this v.low angle scenario! 🤫 🤣

As for the ejecta traces, can’t they be seen clearly in Fig 11 of your Link article? …. and also in the Nighttime Temperature traces you dropped in your post April 25th?

 

[Barry Fitz-Gerald]

You are right, the pesky Zone of Aviodance is difficult to see in this case, but have a look at the Apollo 11 image attached - you can see subtle ridges marked with white arrows which are the edge of the Messier A Zone of Avoidance. The deposits shown with the grey arrow probably came from Messier A during the late stage of crater formation when ejecta did end up being thrown out towards the east - so even though they are called Zones of Avoidance you do get some ejecta in there in many cases. Cauchy is a good example of a crater with a ZoA but where you will find ejecta within it. In the pic the red arrows show the ridges that mark the edge of the ZoA as is the case with Messier A, but if you zoom in you can still see stuff there which was flung out of the crater during the final stages of crater formation. Even though Cauchy is pretty circular the ZoA shows it was a low angle impact crater.

The ZoA in Messier A is also obscured by all the impact melt that came out of Messier which forms the smooth puddle between the two. The fact that the Messier A craters are more rounded than Messier would suggest that the impact angle was not as shallow in the case of Messier A - which could be seen as a weakness in my version, but have a look at Fig.2 in https://www.osti.gov/pages/servlets/purl/1321817    - you can see an elongate ragged crater on the up-range side and a smaller rounder one, slightly offset downrange. But of course this is the result of a lab experiment so extending the interpretation to larger more complex scenarios is not a precise one - but a reasonable guide.  But it leaves some wiggle room for alternatives!

 

Cheers, Barry.

[Drifter]

1 hour ago, Barry Fitz-Gerald said:

Even though Cauchy is pretty circular the ZoA shows it was a low angle impact crater.

Cauchy doesn’t look elongated/elliptical enough to be a low angle impact crater … but best I don’t get distracted by that logic … and just agree with your point about ejecta being thrown back in some impacts! 😙

It’s interesting how much the angle of the sun ‘ironed flat’ the Zone of Avoidance of Messier A! … Your profile graph + the shadow in the other photo made it look much higher than that.
 It came late to me, but I can now see how the sun really glints a high albedo reflection to a very high degree when it hits at a certain angle to some mineral scatter on the surface created by meteor disturbance. Blows apart my idea about a gradation of ‘fluorescent friction burns’ indicating direction of impact.🤔 If I’d seen a multiple of photos of Messier taken with the sun at varying angles on Day 1 … I wouldn’t have plugged that idea for quite so long!🙄 Doh!

Still a bit puzzled why Messier A impact craters appear to be deeper and wider than the Messier crater - when what created them was fragments from Messier - travelling at a reduced velocity and a fraction of the mass?

I’m happy for all these impacts to be unrelated … and Messier to have bounced back out into Space! …. You seem reluctant to consider that? - despite the Moon’s reduced gravity compared to Earth’s? … won’t that make ‘bouncing non-residents’ more likely - if the angle is exactly right - rare but possible? … Guess it depends on the escape velocity needed after Messier displaced so much ejecta laterally. If it was shaped to skim … it could gain some spring and lift from that ejection?

 

[Barry Fitz-Gerald]

'Still a bit puzzled why Messier A impact craters appear to be deeper and wider than the Messier crater - when what created them was fragments from Messier - travelling at a reduced velocity and a fraction of the mass?'

I think you are not alone there, and it is such a strange 'one off' that there is little to compare it with, and the differences in the crater outlines certainly are a conundrum that I do not have the answer too.  That's why alternative interpretations like yours are always worth discussing because it forces you to look at things again in a fresh light. It's easy to accept the standard interpretation - but more interesting to question it. So when you say ' I’m happy for all these impacts to be unrelated … and Messier to have bounced back out into Space!' I would be daft to rule this out as a possibility, because you could very well be correct!

 

Cheers, Barry.

 

 

[Drifter]

…. it just those two long pesky rays of narrow scatter to the west that makes the split idea attractive and distracting  … wonder if they’ve managed to replicate that in lab impact experiments with fragments of a certain shape/size?

… guess there is more to Life, Living and Meaning to be over-analysing stuff like this! 😋 …. how important is it in the Big Picture? …. Is it best to put this one in the Pending tray of Improbability? - Best I move on to shortly replying to those other points you made earlier - [discussing ideas around the chemical signatures that may be creating weathering-resistant high albedo traces like Tycho/Copernicus, the evidence Herodotus and Prinz may be long dead craters of super volcanoes, plus certain conditions that might be forming some rilles in our solar system] … 

[Barry Fitz-Gerald]

Yep - reckon we have squeezed all the juice out of this particular lemon for now!

[Drifter]

On 14/05/2021 at 08:38, Barry Fitz-Gerald said:

As I noted above even with an impactor arriving at cosmic velocities varying from 14kms/sec up to 75kms/sec the energy released is still only in the thousands of degrees C and whilst this will vapourise, melt and shatter the target rock (an the impactor) the temperatures will NOT be in the several millions required for any form of nuclear reaction. Vapourised minerals will be reduced to their component atoms and molecules but these will not have sufficient energy to do anything other than bounce off each other - there will be no nuclear reactions. The tiny amount of water present in the lunar rocks is mostly locked up in mineral structures and will play little to no part in reactions. If any survives the impact it may re-combine in the minerals that form from in the cooling melt - but I would guess most would be dissociated into hydrogen and oxygen or lost to space. When the vapourised rock and impact melt cool and solidify you get - well rock of a similar composition you do not get any exotic products. If you melt basalt rock and let it cool you get basalt rock - might not be the same as the initial rock as it will have solidified under different conditions of pressure/cooling rate/gas pressure and so on - but it will still be basically a basalt.

Digging further on high albedo lunar impacts … this popped up.
https://geology.com/articles/popigai-crater-diamonds/

Diamonds found at the centre of nuclear test explosions on Earth and at the Nordlinger Reis meteor impact site suggest explosions of high intensity can spread tektites and other ‘glass-frozen’ elements thousands of kms … as seen with NR (tektites in Croatia) and with Tycho with debris scattered 5,000 km …. if certain elements are present -  graphite is mentioned being present in some meteors .… if the case for pockets of water being locked as condensate in lava tubes around dead lunar volcanoes - as detected by ground penetrating radar recently - it makes sense that there would be a sufficient catalyst here to fuel the immense Tycho surface impact explosion and scatter pattern

Here is another compound with high reflectance (TiO2) mentioned in the study B F-G dropped earlier.     http://www.psrd.hawaii.edu/Sept04/LunarRays.html#data 

TiO2 has interesting characteristics(from Wikipedia)

Titanium dioxide occurs in nature as the minerals rutile and anatase. Additionally two high-pressure forms are known minerals: a monoclinic baddeleyite-like form known as akaogiite, and the other is an orthorhombic α-PbO2-like form known as brookite, both of which can be found at the Ries crater in Bavaria. It is mainly sourced from ilmenite ore. This is the most widespread form of titanium dioxide-bearing ore around the world. Rutile is the next most abundant and contains around 98% titanium dioxide in the ore. The metastable anatase and brookite phases convert irreversibly to the equilibrium rutile phase upon heating above temperatures in the range 600–800 °C (1,110–1,470 °F)

Titanium dioxide (B) is found as a mineral in magmatic rocks and hydrothermal veins, as well as weathering rims on perovskite. TiO2 also forms lamellae in other minerals.

Titanium dioxide is the most widely used white pigment because of its brightness and very high refractive index, in which it is surpassed only by a few other materials (see list of indices of refraction). Titanium dioxide crystal size is ideally around 220 nm (measured by electron microscope) to optimize the maximum reflection of visible light. However, abnormal grain growth is often observed in titanium dioxide, particularly in its rutile phase. The occurrence of abnormal grain growth brings about a deviation of a small number of crystallites from the mean crystal size and modifies the physical behaviour of TiO2. The optical properties of the finished pigment are highly sensitive to purity. As little as a few parts per million (ppm) of certain metals (Cr, V, Cu, Fe, Nb) can disturb the crystal lattice so much that the effect can be detected in quality control. It is often referred to offhandedly as "brilliant white", "the perfect white", "the whitest white", or other similar terms. Opacity is improved by optimal sizing of the titanium dioxide particles.
 

 

 

Edited December 1, 2021 by Drifter