Here's a little synopsis:
I suggest starting by absorbing the information in the following link from NASA...The Moon and the Magnetotail
Stranger still, moondust might gather itself into a sort of diaphanous wind. Drawn by differences in global charge accumulation, floating dust would naturally fly from the strongly-negative nightside to the weakly-negative dayside. This “dust storm” effect would be strongest at the moon’s terminator, the dividing line between day and night.
The scenario the above article describes is a “diaphanous wind” and “dust storms” between the sunlit and “night” sides, along a band (likely ~300km – 400km wide on average, or about 10% of the moons diameter, imo) that follows the terminator around the entire pole to pole circumference of the surface. This “wind” of electrons and electro-statically charged dust grains can be classified as an electric current sheet, which hugs the surface across the terminator band. I'll describe it as the Terminator Current Sheet.
During the time the moon is within the magnetotail, the TCS has measured voltage potentials of 200v – 1000v. They mention that when outside of the magnetotail there are fewer electrons available to the “night” side, so (imo) the average voltage potential would be less, and fluctuate less severely, potentials are probably on the order of averaging ~ 100v, but the point is that it's always there to some degree. With the sphere of the moon rotating through the TCS, like a globe spinning in a stationary frame, the higher latitudes towards the poles will be within the band of the TCS more frequently, and even constantly in the band, above a certain latitude. The permanently shadowed craters in these latitudes would accumulate a thicker layer (~1-2cm, imo) of these migrating grains and particles, than other regions of the surface (~2-3mm as detected as part of the “hydration cycle”) that receive at least some sunlight, where they can be “sputtered” from the surface more readily than they are in shadows.
Grains of iron (Fe was detected in the plume by LRO) bonded with silicates form dielectric layers in the regolith and subsurface strata, which release ions and electrons under the force of sudden compression. That's a piezoelectric discharge. It would be relatively weak, but enough to add to the mechanical forces of impact to break atomic/molecular bonds producing free atomic/molecular ions, and electrons, which are energized by the electro-magnetic pulse that helped free them, to initiate chemical bonding/reactions, while fracturing some of the material into micron sized grains. The result would be a central column of vapor from reactions, electrostatically charged micron sized dust, and grains of accumulated surface material mentioned above, along with larger and heavier material thrown out around the perimeter. The central column of micronized dust and vapor reaction products would form in a matter of micro-seconds, and be accelerated by a combination of mechanical and weak electromagnetic forces. Charged dust grains would be suspended longer before settling out, than would non-charged grains influenced by gravity alone. Some chemical reaction chains could continue for several seconds after the initial burst of reactions.
What was observed?
A strong UV flash on impact. (NASA: “We aren't sure what that means”) Piezoelectric discharge might be what that means and that UV flash, reported as a flash of sodium, could be evidence to support it.
A rather complex chemical soup, including water vapor, sodium (abundances of Na were a bit of a surprise to NASA, which I predicted btw), carbon dioxide, and possibly methane. I expected a comet like mix of volatile and organic chemicals, and NASA mentioned it was much like a comet, and/or some asteroids. Yeah, I know, previous ancient impacts could deposit similar materials.
A central ejection column of fine dust (finer than expected by NASA, I believe) and vapor that rose more than twice (30km+) as high as predicted by NASA( ~15km). A curtain of heavier material thrown to the sides (which is expected balistically in most impacts anyways) The dust column remained aloft for about four times as long as predicted by NASA. I expected a more energetic impact than NASA predicted, as well as lingering electrostatic dust.
The timeline of the spectrographic data indicate ongoing chemical reactions (NASA mentioned this as part of the data to be examined closer). A very small percentage were actual icy grains so far as they can determine, suspected to be water ice, and the rest of the detected water/hydroxyl groups were in vapor form. I expected that as well, although I'm saying that most of the vapors are by-products of chemical reactions rather than sublimation, and the icy grains are accumulated from molecules and grains migrating across the TCS, of which the water/hydroxyls, among other molecules including CH4
, were created by reactions with solar plasma stream protons and silicates in the lunar regolith.
This is just a different way of putting known physics (geology, chemistry, electromagnetic and kinetic), and observed processes together into a unique explanation that goes beyond a simplistic, purely mechanical description something akin to... projectile hit dirt, dirt fly up, dirt fall down, wow look maybe ice in dat dirt, dudirtdudirt.
Actually, I give the LCROSS mission a 10/10 for accuracy in hitting the designated target, data collection, and their ingenuity in successful utilization of a relatively small budget.