Space/Science — HabitableZone

Space/Science » in reply to Lunar Tectites?.

re: Lunar Tectites?.

Glad to see you starting to agree with me. you kind of remind me of Darrell Futrell...

"The argument that all tectites on the moon would be destroyed by micrometeorites is fallacious. There is plenty of opportunity for tectite-rich layers to be buried by later impact sheets, prior to total degradation. So we should expect lunar preccia samples to include some tectites, at least."

Possibly - but if "lunar tectites" are buried, then clearly they would be buried so deep as not to have been recovered by the Apollo crews. Also, since "lunar tectites" could not be found incorporated into later lunar beccias recovered from the lunar surface, it would seem that if they formed they may simply have shattered by micrometeorite impact.

HERE'S THE POINT:
In the end, I suppose it depends on whether you want to call the "lunar impact glass beads" "lunar tectites" or not...
BUT...

"The fact that they don't fits neatly with the model that tectites are formerly-molten material (perhaps even vapour condensates)"

The heat energies running up a hyper-velocity impact pipe are quite different from those found creating vapours and vapour condensates. BUT Mars is much like the Moon in this regard, as it lacks much of an atmosphere - I do not think that a hyper-velocity impact pipe forms without a constraining atmosphere.

"that have passed through a planet's atmosphere and cooled in the teardrop or discoid shape they adopted under aerodynamic stress while still fluid."

On Earth, only on the way back down, and there is re-heating. On Mars, no atmosphere, and without a pipe, the dispersal should be hemi-spherical.

Again, we often loose sight of the fact that the "atmosphere" of Mars is closer to the vacuum of space than to the Earth's atmosphere. Not enough atmosphere to form a hyper-velocity impact pipe, enough to cool, not enough to atmospherically deform at the temps and velocities produced in this case.

"On the Moon, there is no atmosphere, so the impact glass beads are all spherical, if small enough to chill before re-impacting the surface. There are no big beads because they are too big to cool efficiently (radiation to space is much poorer than conduction to a turbulent atmosphere)."

Yes - further, on the Moon, rather than forming larger beads, simply more beads are formed. The cooling is uniform.

And on Mars, we have these bigger beads because 1) IN THIS CASE the initial temps were lower, and 2) the cooling was more rapid, due to Mars' thin atmosphere.

"Bigger globs of molten material splash back down again, producing spattered secondary beads and local glassy matrix/cements"

I don't think that I've ever seen either spattered secondary beads or local glassy matrix/cements caused by tektites from Earth for sale, but if you say they exist, okay.

"The blueberries are about as far from being tectites as you can get, and your ridiculous desire to classify them as such in the face of numerous lines of evidence demonstrates once again your lack of objective thinking skills, EP."

While we're on the subject of "objective thinking skills", exactly how many times have scientists on the NASA (taxpayng public's) dime made startling announcements about a watery Mars, only to have them quietly repudiatiated and retracted later on?

If I said "impact condensates" no one would understand, and if insisting that they are "tectites" forces the issue, well then, that's the whole point, isn't it?

"EP"
(In my mind, it always rhymes with "Pee")
That s Okay - That sound you're hearing about your ears ain't exactly rain...

Log in or register to post.

The whole thread (22 posts)