[meteorite-list] Re: Re: Tektites II (READ WARNING)

From: meteorites_at_space.com <meteorites_at_meteoritecentral.com>
Date: Thu Apr 22 09:43:32 2004
Message-ID: <20010716041207.17394.cpmta_at_c000.snv.cp.net>

WARNING--- THIS IS VERY, VERY LONG AND INVOLVED, SO UNLESS YOU ARE REALLY INTERESTED IN THE TEKTITE DEBATE-- HIT THE DELETE KEY AND READ NO MORE.

This was so long that I had to use "Word" to write my reply, and the file was huge.

Steve Schoner.




On Sun, 15 July 2001, Kelly Webb wrote:

>
> Hi, Steve and List,
>
> This is my reply to Steve's reply to my reply to Steve's... Wow, way
> too many levels of recursion here. OK, we're going to go to the triple
> interleaved posting format: my former posting (with >'s), Steve's
> replies, and my replies to his replies. To help keep the sequence of the
> three different texts straight, I have added the "speaker's" name to
> each level respectively (WEBB1, SCHONER, WEBB2).
> Got that? You can't tell the players without a program...
> All spelling (typing) errors are mine (except for the ones that are
> Steve's). All other errors are for the reader to judge.

SRS>
This is getting more complicated than it should be-- but here goes...
My rebut is after the "SRS>"

>
> WEBB1:
> > Glass's preliminary guess in 1968 that the Tunguska object had a
> >"composition similar to that of tektites" has been long superseded by
> >more recent and ongoing studies of the Tunguska microspherules, none of
>
> >which bear this notion out. They are largely metallic, not glassy.
>
> SCHONER:
> Probably, yes. I read somewhere that some of these might even be
> related to industrial activity and not the impactor at all. Billy
> Glass, a recognized authority on tektites made the statement, and I
> quoted it. But the jury is still out and I acknowledge it.
>
> WEBB2:
> On of the real mysteries of the Tunguska blast is how little
> physical evidence it left behind, almost a case of no fingerprints. One
> new way of retrieving the microspherules and dust from Tunguska is by
> cutting sections out of trees that were alive at the time of the blast
> and extracting residues from the tree rings associated with that date!
> They show lots of exotic metallic elements.
>
> WEBB1:
> > The microspherules themselves lend no evidence either way on
> whether
> >the impactor was meteoritic or a comet chunk. Actually more
> meteoriticists
> >think the Tunguska Object was a stony meteorite, while more astronomers
>
> >think it was a comet; it seems to correspond to whichever choice is
> most
> >familiar to the theorist.
>
> SCHONER:
> Whatever it was it was fragile. And having fallen on June 30th, and in
> the morning, it might have been related to the Taurid (?) meteoroid
> stream that the Earth passes through at around that time. I am not sure
> if it has been correlated with a comet or an asteroid. But it does
> seem coincidental that it fell at that date, and during a time of each
> year when large fireballs are likely to be seen.
>
> WEBB2:
> Not fragile (see below). 200 bars crushing pressure (3000 pounds per
> square inch) are calculated for the Tunguska Object based on the air
> density at the altitude of its airburst and a "reasonable" assumption
> for its velocity.
> I too agree it was probably a beta Taurid, a daylight meteor stream
> and one of two streams associated with the decaying Comet Enke.
> Personally, I'm certain it was. Well, as certain as I get. Just wait
> until 2042 AD when Ken Brecher's Canterbury Swarm is supposed to come
> back (or not, depending on whether it really exists). I believe in the
> beta Taurids for the simplest of reasons: witnessing a daylight fireball
> half as bright at the sun itself over 30 years ago (on a June 29th).
> It's one thing to read about big potential impactors; it's another thing
> to stand there with your mouth open watching hundreds of secondary
> shadows swing around in unison as one passes overhead. It impressed the
> hell out of me.
> Hey, did we just agree on something?!
>


SRS>
Yes, we agree on this.
 

> WEBB1:
> > The crucial issue in the possible airburst of an impactor is the
> >point at which the dynamic pressure of the atmospheric resistance [p =
> >0.6 x gas density x (velocity)^2] equals the crushing strength of the
> >impactor material. The Tunguska object, whatever it was, exploded at a
> >dynamic pressure of about 200 bars. Whatever it was, it WASN'T weak and
>
> >fluffy. That doesn't necessarily mean it wasn't a cometary fragment. We
>
> >don't know enough about comets to be sure.
>
> SCHONER:
> And we don't know what the effect of impacts to their structure and
> composition will be either. I would assume that they would, because
> they have been hit, and are being hit by other cosmic debris, that their
> composition would reflect that. But more importantly, how will such
> impacts while they are out in space affect the cometary structure? How
> fragile will they be after all of that bombarment? And how will they
> stay together when the do enter a planet's atmosphere?
>
> Questions not easy to answer.
>
> What we do know is that some comets are very fragile, and they break up
> by Solar wind pressure alone.
>
> WEBB2:
> Their fragility, composition, fragmentation are all irrelevant in
> that short dash through the atmosphere at cosmic velocities. I'm going
> to quote you a source here, since I perceive some reluctance to take my
> word for it (don't blame you; I'm the same way).
> I looked in Rocks From Space and other common sources but discovered
> none of these books spell it out the physics of it very clearly.
> From John S. Lewis, Physics and Chemistry of the Solar System,
> Chapter VIII, Meteorites and Asteroids, p. 309ff:
> "Often, small bodies will be decelerated to subsonic speed before
> reaching the ground. About the largest body that could possibily reach
> the ground in one piece, without exploding on impact, would be a
> monolithic chunk of iron, preferably extremely flattened, travelling at
> the lowest possible entry speed, and entering the atmosphere at a very
> shallow grazing angle. The limiting size can be calculated to lie in the
> range of 30 to 100 tons..." (Webb: About the size of the Hoba meteorite,
> you'll note.)
> "For a spherical stone, roughly 3 m in diameter (40 ton) for a
> density of 3 gm/cm^2 is the upper limit..."
> "Fragmentation is unimportant for very large impactors, irrespective
> of size, because the fragments of large bodies do not have time to get
> away from each other before impact with the surface... For a typical
> stone, the critical size (for ignoring fragmentation) is about 300
> meters. Deceleration is important for entering objects only if their
> mass per unit area (essentially pd3/d2 or pd) is less than that of the
> atmosphere above the Earth's surface."
> Webb: Picture it this way. The atmospheric pressure is about 1 kilo
> per cm^2. That means that a mass of 1 kg of air sits on each square cm
> of the surface. Imagine that our incoming meteorites are, oddly enough,
> perfect cubes. For a one centimeter cube to make it through the
> atmosphere without slowing down much, it would have to weigh 1000 grams,
> a very high specific density of 1000.
> But a 10 cm cube would have to weigh 100 kilos, but its specific
> density would only be 100 (100,000 grams / 1000 cm^2). A one meter cube
> would have to weight 1,000,000 kilos, but its specific density would
> only be 10 (10,000,000 grams / 1,000,000 cm^2). I think you can see the
> trend here.
> A ten meter cube would only have to be as dense as ice (specific
> density = 1), a 100 meter cube 1/10 as dense as water, a one kilometer
> cube 1/100th as dense as water, a 10 kilometer cube only 1/1000, and so
> forth. At this point, our impactor is less dense than air, which raises
> other severe problems.
>

SRS>

All the facts and figures aside, you still cannot grasp the notion that
the air at 10 to 20 miles up is sufficiently dense to cause a hypersonic
cometary mass to produce it's crater in the air (Tunguska event) rather
than on the ground. Russian researchers came to this conclusion in
their examination of the effects of the Tunguska bolide. If you want
I could go and find the entire manuscript and post it for your examination
as well as edification.

The breakup was not like a gradual fragmentation, caused by dynamic
atmospheric disruption, but an almost instantaneous blast produced as
the meteoroid pulverized itself in the atmosphere. But it was more than
a simple pulverization. The energy release as the particles came to a
virtually abrupt stop released as much energy in the air as it would have
had it survived intact to the ground.

The rationale behind this dynamic is clear. All the mathematics you
can provide cannot dispute the fact that the Tunguska event was in
fact a cratering event in the air. And that is why there was not a crater
produced on the ground.


 
> WEBB1:
> > The weakest fireball objects burst at 0.1 bar, so obviously there
> is
> >weak and fluffy material out there, corresponding to interplanetary
> dust
> >with densities of 0.01 to 0.10 gm/cm^3. However, your assertion that a
> >10 kilometer weak'n'fluff would never reach the surface of the Earth
> is,
> >well, ridiculous. The factor in determining whether an object will
> >suffer ANY decceleration in the atmosphere depends on the total mass
> per
> >unit area of frontal surface of the object.
>
> SCHONER:
> Maybe my assumption might seem ridiculous to you, but it is obvious that
> such may very well have happened as the tektites indicate. Impact (or
> impactor) products (tektites and microtektites) scattered over areas as
> broad as 10% or more of the Earth's surface and-- not a trace of a
> crater?
>
> And these strewnfield distrubutions cannot be supported by having been
> formed, and ejected from the moon to Earth?
>
> Humm... being skeptical... something is wrong in this picture.
>
> However, there are several tektite fields that do seem to be associated
> with known craters, The Ivory Coast tektites-- Bosumtui (sp),
> Moldivites-- Reis, and Georgia tektites-- Chesapeake Bay crater.
>
> But the Indochinites are the most enigmatic, for they point to some type
> of atmopheric bursting event that liberated enough heat to vaproize the
> impactor as well as ground rocks, throwing them far and wide of the
> epicenter of the event.
>
> WEBB1:
> > Once an object is big enough to have more than 1.057 kilgrams of
> >mass for every cm^2 of frontal area, it's gonna reach the surface of
> the
> >Earth with its cosmic velocity relatively undiminished. The dynamics of
>
> >cometary impact are as well known as that of any other kind of impact.
> >That 10 kilometer fluffball of yours is just as deadly a hazard as any
> >other object with its mass and velocity, whether stone, iron or pure
> >neutronium [kinetic energy = mass x (velocity)^2]. A cometary fluffball
>
> >with the density of interplanet dust particles, if there were such a
> >thing, would reach enough mass to punch through essentially unimpeded
> at
> >the 500 meter size.
>
> SCHONER:
> I do not dispute that objects of the size that produced tektites are
> cosmic hazards to the Earth. Tektites clearly demonstrate that. But
> the fact is that, if they were, as I am convinced that they are,
> terrestrial, and no crater exists then an atmospheric burst (Tunguska
> event) must be the culprit. And though I don't dispute your
> mathematical reasoning, you have not proved that such a "fluff ball"
> (such as are some comets that break up by Solar Wind alone) ABSOLUTELY,
> and without question MUST reach the Earth's surface even if its size be
> at or below 10 Km in diameter. I suspect that there are other factors to
> be considered, such as the angle of entry, the velocity of the impactor,
> as well as its composition.
>
> WEBB2:
> The question really is, how fluffy can the fluffball get and hold
> itself together as an object. A density of 1/100th of water is out of
> the question. That is the density of a Brownlee particle 10 microns
> across. Brownlee particles are that size because that represents the
> maximum size an object that "fluffy" can get. But Brownlee particles are
> soot-like mineral oxides from which the volatiles have escaped. They are
> found floating in the upper atmosphere and, although cometary in origin,
> they cannot be a model for a low-density comet
> I don't know where you got the idea of comets "broken apart" by the
> solar wind.
> I've been through every book on comets I've got handy
> (Yeomanns, Delsemme, etc.) with lots of material on solar wind
> interaction with cometary ion tails, etc., but have yet to encounter any
> such instance of "breakup" cited or suggested. I doubt the idea, but I'd
> like to know if you have a specific source.


SRS>
Oh really... Check out www.spaceweather.com, and follow all of the links
regarding Comet Linear C/2000 A2, shining in the eastern morning skies at
this very moment.. It broke up under the influence of solar wind
pressure, and as it heated up. Comet Kehotek (sp) did the same, and I
watched it do so when I was working at Lowell Observatory in 1974. Then
there is Biela's Comet in 1882, it broke up into at least 6 discrete parts
on its first witnessed passage of the Sun and evaporated afterwards. Then
look at the Comet Shoemaker-Levy impacting Jupiter. Granted the
gravitational forces played a major part in the breakup, but the fact
proved is that comets are fragile-- irrespective of their mass.

And let's examine some of the chains of craters found on the Moon, and
Mars, as well as other moons in Solar system. I remember reading recently,
and after Comet Shoemaker-Levy's impact of Jupiter that such chains
might very well have been produced by fragmenting comets.


And I am sure if I look it up that there are many other instances of
comets being seen to break up in space as they approach the Sun.
IN FACT-- the "M" class comets, the so called "Sun Grazers" (they all
follow the same orbit) are thought to be fragments of a mega-comet that
broke up on its first approach of the Sun 10, maybe 15,000 years ago.

So, if you look you will see that there is more than enough evidence to
indicate comets can indeed break up as they enter denser fast moving streams
of Solar wind and pressure. What do you think causes them to have sweeping
tails of gas and dust that streams as far as 100 million or more miles
behind them? For a comet, solar wind and radiant energy are destructive
forces.


> I've been through every book on comets I've got handy
> (Yeomanns, Delsemme, etc.) with lots of material on solar wind
> interaction with cometary ion tails, etc., but have yet to encounter any
> such instance of "breakup" cited or suggested. I doubt the idea, but I'd
> like to know if you have a specific source.
> At any rate, in a fluffball the size you suggest the tidal forces
> (differential force of solar gravity between the near and far sides of
> the object) are more than enough to rip the fluffball to shreds unless
> it has sufficient structural strength to resist. At the size you are
> talking about, the object would also have to resist crushing by its own
> gravity. Your fluffballs have to be able to survive in their own free
> orbits for long periods. I won't even go into another mystery, how such
> a critter might form in the first place.


SRS>
First off, "fluff balls" is perhaps a bad choice of words.
Comets are not "fluff balls" like the "dust bunnies" that one is apt to
find underneath one's bed. Instead they are probably chunks of gas and
water ice with some degree of porosity. They are most certainly less
substantial then say an asteroid. And more importantly, comets are
not what you say I said and continue to say what they are.

I DID NOT, and I repeat DID NOT say that they are anywhere as insubstantial
as you are claiming.

You have created a "straw man" and are running with it.

Cometary material in the nucleus is not a vacuum, nor are they so
 insubstantial as you are saying (that you claim I said or implied).

Fluff balls was a bad choice of words, and I now admit that seeing where you
have gone with it. But the fact and intent of what I said about comets reveals
their natures.

Solid ice with probably trace or measurable quantities of dust scattered
within.

How "solid" they are is the question. And I think that because they can
break up under the influence of Solar wind and radiant energy is a clear
indication that the ones that do are much, much more fragile than the
asteroids.

Sorry if I seem a bit ticked off here, but please don't put words down
that I did not write, and then knock them down as if they were mine.


>
> SCHONER:
> Some years ago, I saw a very interesting abstract by a Russian
> researcher looking into the dynamics of the bolide that created the
> Tunguska event. His analysis of it, using computer and mathematical
> models incorporating data gleaned from hydrogen bomb tests produced very
> interesting results. As the impactor broke up, according to him, it had
> a "cascade effect" In other words the breakup caused more break up, and
> it progressed exponentially in the span of a millisecond or less, so that
> the energy release was as equal to that of a hydrogen bomb explosion in
> the air(airburst), not only in energy release but in effect as well.
>
> The key point in his analysis as I remember was the total energy
> released in relation to the time element of the release, and the medium
> (air) in which that energy was released.
>
> His conclusion was that the impactor made a "crater" in the Earth's
> atmosphere rather than the ground. Though not a very large body, if this
> was so then impactors do not have to reach the ground to produce
> craters. "Craters in the air" is what can be produced by an impactor if
> the conditions are right.
>
> IN the case of tektites, they are evidence of such events on a much,
> much larger scale than the 1908 Tunguska event.
>
> WEBB2:
> Of course, that is exactly how airbursts happen. No one doubts that
> or has suggested anything else. We can all agree to your craters in the
> air. But how big can they be?
>


SRS>
Certainly larger than 100 km. Air moves faster, and more easily than
solid rock. Air is much easier moved than rock, so I would conjecture
that the crater would be significantly larger.


 
> WEBB1:
> > Ignoring the numerical coefficients, we have a factor here composed
>
> >of density x diameter^3 / diameter^2. This reduces to density x
> >diameter. Even a little simple arithmetic would have revealed that your
>
> >fluffball would have a volume of 5 x 10^29 cm^3 and a frontal area of 8
>
> >x 10^11 cm^2 and hence would have to have a density of less than 10^-13
>
> >gm/cm^3 to be unable to penetrate the atmosphere, or in other words, a
> >density essentially similar to space itself or a very good laboratory
> >vacuum. So, in a way, you're right: balls of vacuum do not penetrate
> the
> >atmosphere!
>
> SCHONER:
> NO, NO, NO! I think you had better go back to the drawing board on that
> one. A cometary "fluff ball" does not mean a vacuum.
>
> WEBB2:
> My point is that your fluffballs in the size you're talking about,
> in order to not reach the ground but aurburst instead, would have to be
> virtually a vacuum or at the least an "airball." Refer to the
> step-by-step density reduction in my previous comment.


Your step-by-step density reduction argument is faulty. It has assumptions
that do not take into account the obvious physical nature of comets. Nor
do they take into consideration the fact an object such as a comet moving
at hypersonic velocity will respond in the same way than a much more solid
body such as an asteroid will respond given the same speed and angle of
attack. I do not confess to be a physicist or a mathematician such as
yourself-- However-- I do see that your assumptions lack certain elements
that are required to explain obvious facts.

That is Tunguska events, and also the possibility based on the physical
evidence that mega Tunguska events can, and do occur-- as the presence of
the tektites attest.

Your calculations need to incorporate a factor that allows for the structure
of comets-- like the comets that DO BREAK UP in space and by light, and Solar
wind pressure alone (Comet Linear now bright in the eastern sky)

>
> SCHONER, CONT:
> Let me give you this analogy. I think that it is a good one and
> illustrates the point well.
>
> Suppose that you take a bullet-- a solid bullet and fire it from a gun
> at a set velocity at a target composed of ballistic jelly. The solid
> bullet will penetrate deeply into it leaving a bullet track in its wake
> as it expends energy. It will either pass through, or come to a stop,
> but all the while expending its kinetic energy until it comes to a stop.
>
> Now use one of the "stinger" rounds, of the same weight, but composed of
> a bullet made of tiny lead shot contained in a polycarbonate shell.
> This round will travel at the same velocity, and strike the ballistic
> putty with exactly the same amount of force and energy yield-- HOWEVER--
> because its structure is not consolidiated it spreads out on impact and
> expends its energy much facter and closer to the impact point in the
> ballistic putty, and more importantly it does not pass through. The
> hole "crater" it produces is in the ballistic jelly, and the majority of
> its damage is inflicted at, or very close to the point of entry.
>
> The amount of kinetic energy of both rounds is identical. What is
> different is how they expend that energy on impact with the target and
> this is related
> to the *structure* of the round AND NOT its mass.
>
> The same effect I think applies to cosmic impactors. Structure is what
> determines how they release their energy in the Earth's atmosphere.
> (And whether they even reach the ground).
>
> WEBB2:
> The analogy of bullets and targets is a very poor one. Cosmic
> velocities are orders of magnitudes greater than what's produced by
> human popguns. Kinetic energy goes up as the square of the velocity. The
> kinetic energy of the fastest bullet is only great enough to deform or
> shatter it. A gram of material moving at 72 km/sec, the highest possible
> intercept velocity at the Earth's orbital distance, has 1000 times more
> kinetic energy per gram than the energy released by the explosion of a
> gram of the most powerful chemical explosive known. In fact, when this
> amount of kinetic energy per gram is released in an impact, less than
> 0.2% is used up vaporizing the impactor; the rest goes into the force of
> the explosion. We measure the impact energy in tons of TNT equivalent,
> but a one-ton body moving at this speed has more kinetic energy than the
> ton of TNT has explosive energy, by a thousand-fold!


SRS>

RIGHT! Now use the above to consider that under certain conditions the
atmospheric pressure will disrupt a fragile body just as solid rock would
a much, much more solid one. In this regard, there is another factor that
you have not considered, how transparent are comets to infrared radiation?

That is if they are entering the Earth's atmosphere at hypersonic speed
the superheated air cap in front of them will also produce enormous amounts
of infrared energy. In ice or fairly transparent solids, as I feel
confident that most comets are, how deeply will that energy penetrate
into the comet itself? What will be the effects as this energy then
heats up the deeper layers and the dust particles within?

I think that under these conditions the comet in question would rapidly
disrupt, it will explode in a cascade reaction-- Just as the Russian
physicists studying the Tunguska event concluded. And this is true for
even the large comets, say up to and including 10 km.

So again, as I point out above-- just because a cosmic body has such and
such a mass DOES NOT mean that when it hits our atmosphere it will also
hit the ground.

The nature of the object in question may introduce factors into your
equations that preclude that.

Back to the drawing board for you...


> The point here is that kinetics on this energy level is, in fact,
> totally unlike conventional earthly events, like bullets. Composition
> matters little. Density shades the results (an iron can be a little
> smaller than a stone and an ice can be a little bigger), but doesn't
> affect the outcome much. Composition affects the outcome less and less
> as the impactor gets bigger and bigger.
> (It's difficult to realize how potent kinetic energy alone can be. A
> gram of anything moving at 7000 km/sec would have more kinetic energy
> than the energy produced by the nuclear fission of one gram of
> plutonium. In other words, shooting a chunk of rock at a planet at this
> speed would be just as effective as a nuclear bomb with the same weight
> in fissionables. At this speed, a one kilogram rock would equal the
> Hiroshima bomb in energy release!)
>

SRS>
Right-- But as I previously stated, the structure of the impactor in
question will also determine how that energy and where in the atmosphere
or the ground that that energy will be released. As it is traveling
through the atmosphere at hypersonic speed it is still acting in the
realm of Newtonian physics. It is expending its enormous energy all
along its path emitting it in the form of electromagnetic radiation,
and or heat.

BUT as soon as it hits something at cosmic speed ALL of the remaining
energy is converted to heat-- instant vaporization of the target, and
the projectile. The law of conservation of energy is in full play and
KABOOM-- an explosion equal to and perhaps many, many times exceeding
that of a thermonuclear device is the result.


When does the particle stop?

Even if the "particle" in question is a very friable comet of substantial
mass-- does it have to stop only when it hits the ground?

That is the question that you seem to be missing.


When I watched the Great Leonid Fireball shower of 1998, I was astonished
at the number of fireballs created by supposed cometary particles. I watched
them shoot across the sky, fast and graceful. And many of them exploded
brightly in a terminal flash. Nothing proceeded on after that, and the
light from them was on the order of magnitudes greater than their brilliance
as they traversed the sky.

Then at the break of dawn as a finale a bright Leonid appeared shooting down
toward the eastern horizon at great speed. Its terminal blast was so
great that it lit up the landscape bright as day, and the whole sky lost
its stars in its brilliance. I was dumbfounded, expecting to hear the
blast from it coming minutes later. But that did not happen. Instead I
watched its final blast cloud warp into an "s" shape brightly visible just
before the sun came up.

This terminal blast I understand occurred at an attitude of 20 to 30 miles.
And the particle that created it was probably a chunk of cometary ice no larger
than a walnut.

BUT it came to a complete stop at 20 to 30 miles up. ( I know this because
I got several reports around the state and from that with a bit of trig,
I was able to estimate the altitude.

HOW much air is up there at 20 to 30 miles?

Enough to stop a particle the size of a walnut traveling at 66,000 mph dead in
its tracks causing it to expend all of its kinetic energy in a terminal blast!

Now, prove mathematically that a very fragile, but a full sized comet significantly
larger on the order of many, many magnitudes larger could not do the same?

Tunguska proves otherwise.

That is what the data reveals.

 
> SCHONER:
> Most larger impactors as you pointed out will reach the surface, but
> even a stony object of the same size as those that do, but that is
> highly fragmented can explode in a Tunguska type event in the Earth's
> atmosphere rather than on the ground.
>
> What is the pressure of the center of an explosion as the blast wave
> radiates out? Correct me if I am wrong, but I read somwhere that in the
> case of nuclear airbusts at 60,000 feet, that such an explosion produces
> a very strong blast wave which then radiates out from the epicenter, and
> milliseconds after that, the dynamic pressure at the center of that
> super heated plasma fireball is *close* to a perfect vacuum. Then in
> the wake of the blast the air rushes back to fill the void. (Take note
> of the old atomic blast footage of the blast wave-- it radiates out,
> then a moment later rushes back.)
>
> WEBB2:
> The question is how big an object can airburst? The lower its
> density, the bigger it can be and still airburst. But there is an upper
> limit to an airburst imposed by the lower limit on density.
> Fiddling with the limits set by tidal forces, self-gravity, and
> structural limitations (below the densities of frozen gasses, only voids
> will lower the density further), I'm willing to postulate that an object
> with a density of 1/10th that of water could conceivably exist.(Frankly,
> I doubt it, but I notice you never say how fluffy you think fluffy is,
> just that it's fluffy enough.) Such an object would be about 85% voids.
> That's really foamy.


SRS>

Again you are reading words into the "fluff ball" that I never intended nor
implied. What you are doing is what I remember in my studies of philosophy
not to do-- Create "straw men to knock down to support one's argument"

The fact is, and as I repeatedly stated before, comets ARE NOT as solid as
asteroids that the impact models are based on. The fact is that we do not
know the physical structure of comets, and or whether Solar radiation can
penetrate its surface and to what extent that penetration is.

In this regard, it is quite possible that the jetting observed on comets,
Halley's in particular is due to the penetration of light and infra-red
energy deep into the surface of it. This could, and most likely is the
reason for the jetting of gasses that were observed from its nucleus. And
this could also be a major reason for them breaking up in the first place.

Again, what would the effect of this transparency be as such a comet
entered the Earth's atmosphere?

I think rapid disruption would be the result as solids in the comet absorbed
energy generated by atmospheric friction, converting it to heat which would
 then vaporize the gas around it causing it to break off the layers above it,
further exposing fresh ice (perhaps more transparent than the layers above it--
on and on and in a millisecond of the start of the process--
 MEGA-TUNGUSKA EVENT-- MILES ABOVE THE GROUND. But with
Bottom of that atmospheric crater touching the ground.

It would be a huge and hot "crater in the air" vaporized cometary material, and
Terrestrial material as well jetting it thousands of miles up into space---

Now do you see the picture that I see?

My brain works like a MAC- Not a PC

I see things in pictures-- It is the way I think. And I see it clearly.


>
> SCHONER:
> Huge, mega-Tunguska events also produce blast waves that are "exactly"
> like thermonuclear blast waves, but on a much, much larger scale. And
> this is why in the early 50's that Dr. Lincoln Lapaz and others though
> that the Tunguska event was caused by an "anti-matter" impactor rather
> than a meteoroid expending all of its kinetic energy in the Earth's
> atmosphere rather than on the ground. At the time, and with the limited
> information and data that was available to them they could not grasp the
> dynamics of a meteoroid disrupting in a cascade of fragmentation in the
> Earth's atmosphere. To get an idea of this, imagine the thing
> shattering instantaneously, and in so doing coming to a complete stop
> high in the air. All of the impactor's kinetic energy would be
> converted to heat, and infrared radiation, and visible light. Instead
> of making the release of such energy in the solid ground it does so in
> the air. There will then be a bright and very intense flash-- just as
> in a thermonuclear explosion. In this regard, Dr. Roddy and previous to
> that, the late Dr. Shoemaker both told me that the energy release
> dynamics of Tunguska type events, are "identical" to the energy release
> dynamics of thermonuclear airburst explosions.
>
> WEBB2:
> No one disagrees with this, Steve. You're making my point for me. In
> a sufficiently energetic event, nothing matters but the raw parameters
> of energy. There's no difference; energy is energy. Whether the energy
> comes from a fast dumb rock or a sophisticated gadget like a super bomb.
> If it's a kinetic event, above a certain energy level it just doesn't
> matter about its composition or structure or anything, whether it's a
> million tons of iron or a million tons of goose feathers.


SRS>
WRONG! Back to the drawing board. Structure does play a part in not only
the release of that energy in the terminal blast-- but when.

Up to the terminal blast the meteoroid is behaving differently than when
that blast occurs. For most impactors that produce craters on the ground
they are vaporizing all the way, dissipating energy all along the way.
There is a shell of plasma in front of them and pressure is being exerted
against them till they either break or impact the ground. When or if they
break up, often it produces nothing more than a shower of meteorites.
But if they hit the ground at hypersonic speed ALL of their remaining
kinetic energy is release in an instant-- Result-- KABOOM--
a crater forming event.

If the structure of the impactor (comets) is such that they not only break
up but vaporize in a cascade (such as the Russian researchers proposed with
Tunguska) then all of that energy is released in that instant or near to it.

Until then, hypersonic objects are behaving pretty much in the realm of
Newtonian physics. But once they abruptly stop at that speed, either in the
air, or on the ground a entirely different dynamic takes place.

Conservation of energy, thermodyanamics, enormous kinetic energy turns
to enormous heat.

Structure of the body in question DOES play a part in how the process
unfolds. Whether it be on the ground in a cratering event or high up in the
Earth's atmosphere in a terminal blast (crater in the air) structure does play
a part


> The question is, as always, how big? Ok, I gave you your 1/10th of
> water density. That reduces to the following maximum airburst, that is,
> it just barely fails to hit the surface. The object is about 130 meters
> in diameter. It weighs about 90,000 tons. The impact energy is around
> 5,000,000 tons of TNT equivalent. That 5 megaton burst is sort of medium
> for a fusion or boosted fission bomb. (The biggest "H-bomb" ever
> exploded was 60 megatons, by the Russians.) That's the top yield for a
> low density object possible in an airburst. The object could be much
> bigger, of course, but then it would reach the surface and create that
> crater you're trying to avoid.


Try Tonle Sap in Cambodia--- It may very well be be just such a
"crater that I am trying to avoid"

An airburst of the magnitude that would otherwise have produced a crater
on the Earth's surface of 100 + Km in diameter would and probably did
produce some depressions on the Earth's surface. Our problem is to be
able to recognize them as they I imagine would be substantially different
than what would have been produced had the impactor reached the ground.

A model must be formulated that shows the effect of a Mega Tunguska event
not only to the air, but to the ground as well.

My conjecture is that such ground effects will be much less noticeable
that the more straightforward ground impacts without a Tunguska type
airburst.


> The real Tunguska object produced a much bigger explosion (about 5
> times bigger). Its burst pressure of 3000 pounds per square inch
> (compared to the much lower bursting pressure on your low-density
> object) is what created the higher yield.
>
> SCHONER:
> IN this regard a mega-Tunguska event in the Earth's atmosphere would
> most certainly generate enough energy to "blow away the Earth's
> atmosphere" and create a virtual superheated vacuum as the fireball
> expanded, and additionally, the wake of the fireball (its track through
> the Earth's atmosphere) would also serve as a "conduit" for any impact
> generated materials that would be ejected into space as the flanged
> Australasian tektites indicate.
>
> WEBB2:
> There can't be a mega airburst. Airbursts, as the physics of the
> situation limit it, are confined to a narrow range. That range lies
> between, on the one hand, airbursts that occur so high up the blast is
> dissipated and unnoticed at the Earth's surface (likely very weak
> objects and/or very fast ones) and airbursts that occur just short of
> the surface and which transmit most of their force to the Earth below.
> Tunguska is an example of that. The many nearly megaton blasts at very
> high altitudes detected by early warning satellites like the DSP-647's
> (hush, hush) are examples of the former. These weak objects, whatever
> they were, are probably the closest thing in the real world to your
> hypothetical low density objects, Steve, but don't rush to the DoD to
> get the data, because they threw the data away after they decided they
> weren't weapons. Military... intelligence?


SRS>
Your point? Again you seem to be going to the "low density" object.
You are talking about one thing and I another. A Mega-Tunguska event
will not be like what you propose in the above. And the dynamic pressure
of an atmospheric thermonuclear explosion at the center of the explosion
and in its plasma is close to a lab vacuum at some stage in its evolution.

Now in a Mega Tunguska event, I never said that these occur only at
very high altitudes-- they can happen and probably did happen at altitudes
between 5 and 20 miles. And forming a crater in the air can blow away
the atmosphere from he ground up to space itself.

Now , go back and figure the above for an object that explodes five to ten
miles above the Earth. Tell me that the effects will NOT be noticed.

Tunguska--- And that was a small one.

>
> SCHONER:
> Study the dynamics of the Comet Shoemaker-Levy impactors to the planet
> Jupiter to get a grasp of the process. The impactors expoded in the
> Jovian atmosphere and the blast plume then went up through the bolides
> wake. So if such happened there, such could and most likely did happen
> here on Earth.
>
> Tektites serve as the evidence of such events.
>
>
> WEBB1:
> > But, hey, we knew that already. That's what the backs of envelopes
> >are for. When we get these great notions, like, I'll bet there are big
> >comets so fluffy they won't penetrate the atmosphere, we do the
> >arithmetic first to find out whether it's in the ballpark (or even if
> >there is a ballpark). This notion is a complete non-starter.
>
> SCHONER:
> As I pointed out, Kelly. I am no "arithmatic expert" (spelling either),
> but I think that the basis of your calculations are wrong. If you start
> out with the wrong assumptions, you will get wrong answers.
>
> WEBB2:
> All science is at bottom quantitative. Verbal analogies and images
> are more often misleading than helpful. Only crunching the numbers, or
> even just approximating them, produces a clear mental picture.


SRS>
But the product of such "crunching of numbers" is only as good as the
data that goes into the calculations. Raw data and mathematical
assumptions that do not incorporate all of the facts can be just as
wrong as philosophical analogies.

Garbage in-- Garbage out applies just as well to mathematical approaches
as it does verbal ones. Mathematics is a language, and it abides by the
rules of logic just as much if not more than speech. .

So, there you have it. Your equations only address energy yields of
terminal blasts. They only address rough density estimates for objects
that YOU are speculating about.

BUT you have not, nor can I or anyone at this time provide the data
regarding the nature of comets, ie their transparency to radiation, and
the structure that WILL factor into whether they make it to the
ground to produce a ground crater and release essentially what will be
thermonuclear levels of energy, or whether they will do the same in
the air.

What we should be talking about is the events that lead up to that
release-- not the release itself. The question here is whether comets can
terminal blast in the air rather than on the ground..


>
> SCHONER:
> The fact is that Tunguska type events happen. And in the case of the
> Tunguska event, with impactors that may very well be much more
> substantial in structure than most comets. And I think that if you go
> back and plug into your equations some figures that show angle of entry
> variables, velocity of known comets, and also factoring in suspected
> struture based upon ovservation of fragmenting comets-- I am confident
> that your arithmatic will show that such impactors DO NOT necessarilly
> HAVE to reach the ground just because they are large.
>
> They produce their craters in the air, and close to the ground, but not
> so much in it.
>
> And impactor solids, along with that from the ground that was vaporized
> or melted by the air blast is then blown far and wide over the surface
> of the Earth, as the tektites and microtektites are found today.
>
> WEBB1:
> > As for Michael Pain's article answering my questions, it was
> Michael
> >Pain's article that was summarized in the CCNet post which raised the
> >questions for me. I repeat, the notion of an impact of this magnitude
> >--- 10,000,000,000,000 tons of TNT equivalent --- having occurred so >
> >recently and without leaving unequivocal and substantial evidence,
> >obvious traces, is ludicrous.
>
> SCHONER:
> Air bursts. Mega- Tunguska events, just as I explained, and as he
> explained could and most likely are the cause for tektites.
>
> WEBB1:
> > It reveals the increasing intellectual poverty of impact dogma to
> >require an impact of this magnitude to create the Australasian field
> and
> >be unable to find any trace of that fresh hole --- 70 miles across and
> >12,000 to 20,000 feet deep --- in Indochina or anywhere else.
>
> SCHONER:
> Craters in the air. Try to grasp the concept.
>
> A crater in the air with the bottom of it reaching, but not penetrating
> into the ground.
>
> That is what I and others think created tektites. It is a process that
> apparently happens only very rarely on the Earth.
>
> 34 million years ago in what is now Texas, and about the same time for
> the Georgia tektites.
>
> 14 million years ago for the Moldivites
>
> 800,000 years ago for the Indochinites.
>
> Oh, and I forgot the Ivory Coast tektites-- was that 6 million years
> ago?
>
> WEBB2:
> No. 1.3 million years ago.


SRS> Thanks, I did not think that the 6 million figure was right, hence the
question mark.


>
> SCHONER:
> How many ground impacts have happened over that span of time? Many more
> than that. So I think that "air burst" events that produce their
> "craters in the air" are not nearly as common as those events that
> produce their craters on the ground.
>
> WEBB1:
> > You can't bury all traces of a crater 1/3 the size of Chicxulub in
> less
> > than a million years. (Back to arithmetic: it would take depositation
> of
> > 1-2 meters of sediment per century to fill the damn thing in and bury
> > it in so short a time.)
>
> SCHONER:
> Again, Kelly, your assumption evaporates and has no validity when one
> considers that Mega-Tunguska events produce their Craters in the *air*.
>
> And the dynamics of air rushing back to fill that void is the
> explanation for the distribution of tektites as they are found on the
> Earth today.
>
> I repeat-- You won't find a crater for the largest tektite field because
> the crater was in the air, and not on the ground. The atmosphere was,
> as I previously said, "splashed away" by the impact event, vaporizing
> both the impactor and the ground close to the bottom of the atmospheric
> crater itself. The crater is gone, filled in by air returning to fill
> the void, and the tektites are left as the only evidence that such an
> event occured.
>
> WEBB2:
> Again, airbursts occur in the range between a few kilotons of TNT
> equivalent and perhaps as high as 50 megatons (dense, slow, weak
> objects) and I sure wouldn't want to stand under one. But these energies
> are insufficient to create tektites. Since airbursts this size are not
> that uncommon, if they created tektites, even little fields of them,
> there would be many small tektite fields all over the planet. But there
> ain't. And since airbursts are limited in maximum size, they couldn't
> have produced the big fields of tektites either.
> I know John Wasson (1991) first floated the idea of cometic
> airbursts to explain the Muong Nong glasses, but you'll notice that he
> hypothesized a huge number of airbursts all in the same place to do it.
> The one big airburst can't occur. The problem with the many little
> bursts is that it's a hell of a coincidence.


SRS>
REALLY! I did not know that John Wasson proposed this? In fact it
might prove much of what I am saying if one considers that a comet might
break up the very instant that it hits the Earth's atmosphere! 50 to 70 miles
up! Then as I proposed the transparency of its ice could then result in the
production of numerous airbursts. BANG-- BANG-- BANG one right after
the other and in short order.

Interesting, but probably not the case. We must know more about
comets to come to is conclusion. But I think Dr. Wasson's idea very interesting
considering the suspected nature of comets, and their fragile natures.


> But the "experts" quoted in the M. Pain article are saying that to
> create the Australasian field an energy release of 10,000,000,000,000
> tons of TNT equivalent are required, that's 10 million megatons. That's
> a 100,000 times bigger than the biggest airburst possible. It's bigger
> than big. It's 2000 times bigger than a full nuclear exchange. It's
> bigger than a Hollywood movie about asteroids. It's a major piece of
> planetary asskicking. Big.
> It had to leave a mark... if it happened. Glass and Lee's 114-km
> crater --- if it existed --- would be the fourth biggest crater on
> Earth. And it's too new to hide.


SRS>
NOT UNLESS IT WAS IN THE AIR! And even though YOU cannot
imagine it does not mean that it did not happen . Tektites are the Cheshire
Cat's smile-- for one very big "cat" crater in the air-- long gone.
 

>
> WEBB1:
> > And, tektites do not have the "composition" of terrestial rocks, any
> >terrestial rock.
>
> SCHONER:
> On the composition there is no disparity between terrestrial rocks and
> tektites. Water is virtually absent, and that is about it.
>


> WEBB2:
> The presence or absence of water is part of its composition, isn't
> it? I call that a major disparity. Earth got water; Venus don't ---
> makes a big difference to me. If I go to Venus, I don't pack my beach
> sandals.


SRS>
Water was vaporized in the melt, and I suspect dissociated into its
elemental components-- gaseous hydrogen and oxygen. The hydrogen
was as I mentioned ejected out into space as the vaproized cometary
terrestrial solids re-combined to form tektites melts.

That is my explanation for the lack of water in tektite composition.
And it makes a HELL of a lot of sense when one considers that a temp of
only 7,000 Degrees F is required to do this.


>
> SCHONER:
> As I quoted, Billy Glass, (a noted expert on tektites) said as much.
> And others that I have spoken to that are currently doing research on
> the tektite problem have also said as much.
>
> So....
>
> WEBB1:
> > There is no match for tektites anywhere on Earth. Even
> >if by "composition," you mean "bulk composition," there is no match.
> >What you are referring to is a set of plausible hypotheses that certain
>
> >mixtures of terrestial materials subjected to certain very extreme
> >conditions might produce something like a tektite. It's quite possible
> >that they're produced that way, but it's hypothesis, not proof.
>
> SCHONER:
> I am glad that you can admit this, Kelly-- because that is most likely
> the case. The proof will come, sooner or later. But I think probably
> in the next ten years the question will be resolved.
>
> And the answer will be that they are terrestrial impact products caused
> by "air burst" events.
>
> WEBB1:
> > Go grab >some rocks and a big electric vacuum furnace and cook me up a
> >tektite. That I'll believe. That would be proof. It's been tried, by
> the way,
> >many times, and nobody's ever succeeded in making a tektite. Unique and
>
> >perverse little things, that's why they're so interesting.
>
> SCHONER:
> Until the middle of the last century no one could create diamonds in the
> lab either. Man had an understanding as to how they might have been
> formed
> but did not have the tools to actually make them.
>
> And to date, I don't think that anyone has been able to re-create the
> conditions that would occurr during an air burst Tunguska type event.
> Conditions at, or most likely exceeding a Tunguska event are required to
> form tektites. We simply do not know enough about it, or the conditions
> of such an event to bring about the creation of tektites in the lab.
>
> Just because we can't at this time re-create them, does not mean that we
> cannot come to an understanding as to the processes that created them.
>
> This is what science is doing now, and the evidence is mounting that
> they were created in terrestrial impact events.
>
> WEBB2:
> Actually, we have conducted experiments that could be considered
> tektite forming tests: nuclear bomb tests. Bomb tests were conducted in
> places with plenty of sandy soils (Nevada, atoll islands) to provide the
> silica. The temperatures are certainly high enough! Billy Glass has
> written about nuclear glasses and compared them to tektites. The low
> water content of 70 ppm of the driest nuclear glasses is bandied about
> as "proof" that any really energetic event on the face of the Earth
> could produce tektites. But if you looked at bomb glasses, you would
> never mistake them for any kind of tektite; they are rotten with
> xenoliths, structurally dissimilar in almost every way. (Even the ones
&#61656; produced by airbursts.)


SRS>
Glad you mentioned this.. as I grew up at on the White Sands Missile Range
Base. My dad was a rocket technician there in the late 40's and early '50s.

He took me to the atom bomb site when I was five and I vividly remember it and the
glass that you mention-- Trinitite. I picked up quite a bit of it, and still have it as
a momento of that visit more than 45 years ago.

You are right, there is no similarity between it and tektite glass. Why---
because the conditions were not the same! One 15 kiloton atomic blast is not,
even by your own and very lengthy admission anything like a Mega Tunguska
event that would presumably create tektites. Nor did the first atomic blast
blow away the atmosphere all the way to space (cavitation) so that the vaproized
materials could re-solidify in a near vacuum. Nor does atom bomb glass (Trinitite)
represent a sampling from a very, very large region, such as a tektite producing
airburst event most certainly would.

Though the temperature is there that is about as far as the similarity goes.

So, your analogy, and the assumptions derived are faulty.

>
> SCHONER:
> I must add, that I am not an "expert" on tektites. In the past I sided
> with Harvey Nininger in his thoughts that they came from the Moon. But
> in discussions with Dr. John Wasson and others who have spent many
> years in the field and the lab studying them, my opinion has changed.
>
> (And I might also add, that Harvey Nininger's position changed, too.
> More than a decade after the Apollo Missions, and in one of the last
> conversations that I had with him, when the subject of tektites came up
> he felt that they were not from the Moon as he had previously proposed,
> but as the mounting evidence at that time indicated from impact events
> to the Earth.)
>
> We talk about speculation?
>
> The fact of the matter is, and as I pointed out before, there is
> ABSOLUTELY NO solid evidence that they came from the Moon, and there is
> ABSOLUTELY NO solid evidence for a tektite parent body, and or
> meteoroids.
>
> WEBB2:
&#61656; I never said they came from the Moon.

SRS> Good, then what are we arguing about?

&#61656; WEBB2
&#61656; As for the possibly of an unique impactor of tektite-like
> composition, its chief virtue as a theory is that it would explain the
> total absence of any trace "contamination" of extra-terrestial
> (meteoritic) materials in tektites. In the standard (Melosh et al.)
> model of impact, the highest velocity ejecta is produced from the back
> central portion of the impactor as it is crushing the target surface and
> before the impactor itself vaporizes and explodes. This is the only
> ejecta that leaves the scene without mixing with "target material." If
> the tektites are produced from the terrestial "target" material by a
> common impactor (meteoritic) they will be inevitably be contaminated to
&#61656; some degree with impactor material. And they are not.

SRS> How are you so sure. Basic bulk composition is consistent with Earth
 rocks. Billy Glass and others have said as much.

> The chief objection to the tektite impactor theory is the absence of
> small randomly falling pieces of tektite-like meteorites all over the
> Earth. Unless you can figure out how there can only be big tektite
&#61656; impactors and no little ones, it's a pretty good objection.

SRS> Right! We are in agreement.

> I am only surprised that fewer theorists see that the absence of
> impactor contaminants is a fatal flaw in the impact theory of tektite
> origin, and that nobody much has pushed the tektite-like impactor
> theory. (I get soft-hearted over orphan theories.) Bob Haag's '97
&#61656; catalog says a good word for it.

Come on! What are we looking for? We don't even know for sure the
bulk composition of comets, the most likely culprit in tektite formation.
How much solid material besides gas and water ice is there. Estimates
 have been attempted in making comparisons of the gas and dust tails of
comets, but objections to this are from those that say that the surface of
a comet may not be anything like its icy core. Dust on its surface may
be a coating caused by eons of dust bombardment, as well as being
caused as the original comet shrank over the eons, thus putting a dust
"pavement" on its surface.

What are we looking for-- what are cometary trace elements, and or
Gases? We plain and simple do not know enough about them to determine
what to look for.


>
> SCHONER:
> BUT-- there is mounting evidence for a terrestrial origin.
>
> So, based on the information at hand, what conclusion can we at this
> time draw?
>
> I think that the answer is becoming clear.
>
> WEBB1:
> >The isotopic compositions do indicate that tektites are derived from
> >a differentiated body with a secondary crust. But the Earth is not the
> >only such body, only the one we're most familiar with.
>
> SCHONER:
> Yes, that is where they came from-- The Earth after impact events to the
> Earth's atmosphere created them.
>
> One piece of evidence that shoots all tektite meteorite theories, and
> Lunar origin theories down are as I originally proposed-- the very rare
> Stretch tektites.
>
> After very luckily acquiring the one that inspired all of this
> discussion at the last Tucson Gem and Mineral Show and going back to the
> Macovich Meteorite room to admire it in a brief quite moment-- it hit me
> like a revelation-- the significance of the is form in the tektite
> mystery.
>
> Looking at it, and knowing the mystery, it hit me, it struck me in an
> instant as I saw it.
>
> These are the "smoking guns" in favor of terrestrial origin-- for there
> is absolutely no way that such a form could have survived falling from
> the Moon or anywhere else in space passing through the Earth's
> atmosphere at 7+ miles per'second.
>
> NO WAY-- it is logically impossible. And Darryl Pitt's meteorites, in
> the displays around me, fusion crusted, and ablated were evidence as to
> what the atmosphere does to bodies traveling through it at hypersonic
> speed. The flanged buttion tektites, too. Even they, ablated as they
> are and directly related to and contrasting with the "stretch" form
> indicated what happens when such objects travel through the Earth's
> atmosphere at hypersonic speed.
>
> One would really have to "stretch" logic as well as science to explain
> them falling from space and then arrive on the Earth and still retain
> that stretch form. And the extraordinary stretch tektite that I have in
> front of me at this moment, with stretched bubble holes almost touching
> the surface, and a few breaking that surface, show absolutely no
> ablation that one would expect to see had such an object formed in the
> vicinty of the Moon or space and then fell to
> Earth.
>
> Nor do I buy the notion that stretch forms were formed by a "tektite
> meteoroid" breaking up in the Earth's atmosphere. Distribution problems
> exist with that notion. For to spread them out in the known
> strewnfields as they are would have also created the "crater" on the
> ground that everyone seems to be looking for. Also in this regard,
> tektites are much stronger material than comets. A tektite impactor
> would would therefore have a much greater likelihood of reaching the
> ground than an icy, "fluff ball" comet that breaks up under the influnce
> of the Solar wind.
>
> So, the bottom line, the final piece of evidence that shoots down all
> Lunar, and tektite meteoroid theories is the rarest of tektites-- the so
> called "Stretch" tektites. Where they are found, close to the epicenter
> of the presumed air burst event, and their condition, lacking ablation,
> speaks volumes as to the origin of these strange objects.
>
> On Earth.
>
> And if not, then I challenge one, anyone far and wide, to explain how
> such a form could be produced on any other cosmic body, other than the
> Earth, then fall to Earth at hypersonic velocity, yet still retain its
> form which was clearly, and beyond doubt formed at or very near its
> point of origin.
>
> I repeat it again-- The "smoking gun" for terrestrial origin of tektites
> are stretch tektites, and I think that tektite researchers should
> closely examine these forms in their quest to resolve the tektite
> enigma.
>
> Steve Schoner
> http://www.geocities.com/american_meteorite_survey
>
> WEBB2:
> Now we're on a completely different subject. The surface features of
> tektites and their causes has been an unresolved quarrel for nearly a
> century. One school holds that the pits, grooves, and myriad surface
> features are all the result of terrestial etching, acidic erosion eating
> away at glasses of differing composition at differing rates to produce
> the features. Another school holds that the surface features are
> ablative in origin, the most obvious ablative form being the flanged
> button, of course. Shapes have been explained, successfully I think, by
> the rotation of molten spheres on single and multiple axes.
> The "stretch" form was still virtually molten liquid glass inside
> with a thin, newly solidified surface when it landed, cracking its
&#61656; "shell" and exposing the molten "taffy" inside.

SRS> Right! But I think it happened in the air, and by centrifugal force.
(at least in the very spectacular piece that I have)
&#61656;
&#61656; The problem is that I
> can think of many scenarios that could end this same way. I understand
> that Nininger eventually decided that the "stretch" forms couldn't have
> stayed molten all the way from the Moon and so couldn't support lunar
> origin but rather refuted it. But it does prove that the surface
> features are not terrestial etching.
> The ablative theory appeals to me, but I'll be damned if I can see
> how this crazy variety of surface features could be produced by
&#61656; ablation. I keep trying to, though.

SRS> That bizzare surface might have been created as the vapor condensed.
It is certainly not a product of ablaition, and even the half flange button that
I have in my hand shows that the front side is smooth, and the backside has
that peculiar tektite surface. Flanged buttions formed in space from the rapidly
expanding vapor cloud, then cooled in space, traveling thousands of miles on
a ballistic trajectory till they re-entered the atmosphere over Australia at
hypersonic speed. Too bad we can't find a ring of them all around the impact
site-- I am sure that they exist, but are buried in sediments on the ocean bottom.

All that one would have to do then is draw a line to the center of the circle to
Find the epicenter.


> And since this is a completely different subject, let's save it for
> the next round of the tektite wars. Even I think this is enough... Hey,
> at this point, if anybody still reading this post? Show of hands...
> In summary, I see major flaws of one kind or another in ALL the
> major (and minor) theories of tektite origin. Since I am not by nature a
> negative nitpicker about most things, I think that is because some
> important element is missing or has been overlooked or has not yet been
> thought of. But I can't tell you what it is. Since I've been puzzling
> over these odd rocks for many years, I'd like to know the answer.

SRS> So would I. And we agree again. In my opinion, and for the
 reasons previously and extensively stated, I am convinced that they
originated on the Earth in incomprehensibly immense Mega Tunguska
events.

Now, if this is certainly the case, as the evidence seems to indicate, then
it is up to the number crunching specialists to come up with a model that
explains it.

Sort of like the Pyramids of Egypt. We have no doubt that they exist, but
the never ending question is how could they have done it?

Seems that some natural mysteries, such as in tektites, offer just as much
 if not more than archeological ones.

> The fact that I'm writing this on a Saturday night proves one thing,
> to me at least, and that is, I've really got to get a life...
>
&#61656; Sterling K. Webb

SRS> Ah… same here, we agree again… Time for me to "get a life" and
be with my family.

Steve Schoner, AMS
http://www.geocities.com/american_meteorite_survey.


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Received on Mon 16 Jul 2001 12:12:07 AM PDT