[meteorite-list] Carancas: Arsenic smell ?
From: Dave Gheesling <dave_at_meteoritecentral.com>
Date: Fri, 20 Mar 2009 00:34:37 -0400
The thinner atmosphere on Mars -- and the lower minimum atmospheric entry
velocity due to its gravity -- should only mean that the modeling to produce
surviving meteorites that look "just like they look on Earth" would be
different for Mars re: entry velocities and angles, etc. Presumably this
data already exists, and if anyone has seen it please pass it along...
I believe fusion crust is created not only by the heat of atmospheric
friction but also by the heat generated through high pressures, the latter
generated by a column of molecules simply not having the time to "get out of
the way" being rapidly compressed rather than smoothly displaced.
Regardless, ablation is indeed a fact. Meteorites don't enter our
atmosphere attached to spheres, and presumably that artificial contraption
may have made for a different-than-typical result.
Think horse, not zebra, and think Occam's Razor. There is no doubt much
left to be learned, but extraordinary claims require extraordinary evidence.
An open mind is essential, but I'm not sure a predisposition to assume the
utterly remarkable is called for here just yet. I would also like to hear
from potential resources who might be holding off on the publication of
something fascinating; if memory serves, it was essentially the lack of
agreement on the "impact structure" in Peru that led to the digging in of
heels on opposing sides, but I was unaware that uncovered anomalies may not
yet have been published and would very much like to learn more...
From: meteorite-list-bounces at meteoritecentral.com
[mailto:meteorite-list-bounces at meteoritecentral.com] On Behalf Of Darren
Sent: Friday, March 20, 2009 1:07 AM
To: meteorite-list at meteoritecentral.com
Subject: Re: [meteorite-list] Carancas: Arsenic smell ?
Off-list argument relisted because-- well, the content has great potential
for much wise input from other list members.
On Thu, 19 Mar 2009 20:11:45 -0700, you wrote:
>Lets back up a bit here. You know very well that my posts usually argue
>against what we think we know. I think there is an over average amount
>of guessing in meteoritics when compared to other Sciences.
>There are a great deal of things that we simply have no way of knowing.
>There is a well known photo of a meteorite sitting on Mars. We know
>it's a meteorite because it looks just like they look on Earth. Why is
>Do they Ablate the same while traveling through Mars' atmosphere?
Answer-- no. Mars has a much, much, much thinner atmosphere than Earth.
There will be ablation, but not to the same degree.
>this ablation question came up was to question whether or not we know
>what meteorites look like prior to entry into Earths atmosphere.
Many asteroids have been imaged while in space. Some have been studied from
close-up. Some small ones have been photographed very near earth. We know
what THEY look like in space, and have no reason to assume that the ones
that happen to intersect with Earth's orbit would look different from the
others. Moreover, none of the asteroids we photograph in space have
anything resembling a fusion crust, nor do we know a mechanism by which an
asteroid is space would require a fusion crust. Moreover, even if a
meteorite HAD a crust formed over it in space, the crust meteorites is
composed of the same material of which the meteorite is composed (or an
oxidized version of same) -- material with a melting point far below the
temperature meteorites are known to experience as they pass through the
atmosphere. Therefore, any crust formed in space would burn off during
>I mentioned this study to point out that not all material ablates to
>form a fusion crust that would change it's appearance.
That may be what you meant-- but it is NOT what you said. You said that
ablation did not take place, which is not true. Not only were the samples
ablated, but they were improperly placed on the heat shield so as to not be
at the maximum heat point where they were supposed to be-- ablation would
have been even higher (possibly complete) if the samples had been properly
placed. AND at least one of the samples weren't properly assembled so as to
protect the bacterial samples on the bottom (and who knows what happened to
>at some point in their journey. And by the way the wind pressure while
>traveling out to space could have done this damage to the rocks.
>We cannot assume the ablation was caused by reentry at all.
Yes, we can.
>In fact because no black crust appeared we can say that this experiment
>proved nothing about the actual cause of black crust at all.
We know what causes the black crust-- melting of the meteorite's surface due
to the heat of atmospheric friction.
>Maybe if they had fusion crust prior to reentry they would have ablated
No. Because the fusion crust is made of the exact same material as the rest
of the meteorite, with the same melting point. If anything, it would have
began ablation MORE QUICKLY because the black crust would absorb more heat.
>looked like prior to entry. I went on to point out that we have all
>seem pictures of meteors fly across the sky only to re-exit our atmosphere.
Okay, I'll give you that one. One of the rare meteoroids that enters the
atmosphere deep enough to start ablating but then skips back into space
likely has a fusion crust. A fusion crust formed by Earth's atmosphere,
like other fusion crusts.
>survive while others don't. Maybe something else gives them this tough
>surface we call fusion crust? This is one of the questions I have .
The fusion crust isn't tough-- it is a very thin, very fragile thing that
weathers away very quickly if the meteorite isn't found and "rescued" from
>Another is why have we not figured out an easy way to authenticate
>whether a rock is even from space.
And there never will be a easy way-- if it looks like a meteorite to someone
who knows meteorites, well, then it can be tested. But any meteorite that
looks just like an ordinary rock, in an area where you would expect to find
ordinary rocks, will sit there forever without being tested.
>Moon rocks the only way to tell them apart is by chemical analysis.
>So, you find a rock from the moon with no crust all scientist assume it
>is from Earth.
Not always true. As Randy Korotev himself pointed out once on the list when
discussing possible lunar breccias, a lunar breccia will have random sized
pieces (some very small, some very large) that are not rounded-- terrestrial
sedementary breccias will usually have all the pieces of a similar size,
with rounded surfaces. Look at photos of lunar breccias on google and
you'll see those features.
>coating. If there were an easier way to tell them apart we would find them.
>I have rocks that look just like the collections of Moon rocks but
>unless you can find a scientist to study it , it will never be discovered.
There is an old saying-- "if you see hoof prints, think horse, not zebra."
(Of course, that wouldn't apply in Africa.) You must look at mundane
explainations for something before you start looking at exotic ones.
>I am not trying to disprove any science I just want to wake up a few
>scientists to realize that we don't know everything yet.
Yes, there are countless things that are not known to science. The
temperature at which a given mineral melts and the temperature that a
meteoroid is subjected to as it passes through the atmosphere are not among
those unknowns, however.
If you have an ice cube, and you put it in a room where the temperature is
80 degrees F, that ice cube is going to melt. If you take a rock with a
melting point of 1,000 degrees F and subject it to frictional temperatures
of 3,000 degrees F, that rock is going to melt just as surely as that ice
cube in a room.
There is no "ablation theory of fusion crusts" any more than there is a
"melting theory of why my ice cube is a puddle"-- it is a simple fact based
on knowledge of the materials that compose a meteorite and knowledge of how
much frictional heating a meteoroid entering the atmosphere would be
>You have a way of pushing buttons but of coarse that is what you live for.
For some, "pushing buttons" seems to mean "disagreeing with what you say,
and saying so."
>you live for. Isn't it? The stuff I said about Cosmo chemistry is true
>but as soon as a scientist publishes it the community will be up in arms.
Again, "if you see hoof prints, think horse, not zebra"-- the chances of
making a monumental new discovery are much lower than the chances of having
just another H4-5. If anyone involved in studying Carancas who has found
"inexplicable cosmochemistry" in it that they are "unwilling to publish", is
reading this, can't you at least mention it here?
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Received on Fri 20 Mar 2009 12:34:37 AM PDT