[meteorite-list] FW: Rocks from Space Picture of the Day -May 8, 2010

From: thetoprok at aol.com <thetoprok_at_meteoritecentral.com>
Date: Sun, 09 May 2010 12:05:06 -0400
Message-ID: <8CCBDA8867ED76A-18B4-1DB51_at_webmail-d064.sysops.aol.com>

Hi Rob, List,

I'd like to address a couple of points Rob made. I have great repect
for you Rob, you are one smart dude, no doubts here!

No disrespect intended to anyone out there, we all have opinions and
that's what makes it all so fun! (Sorry to Phil and Warren for my
"full of it" comment last night, I was having fun at your expense and
should not have
made the comment, nothing personal.)

First, I don't believe anyone here thinks of the Franconia irons as an
independent fall. It is widely known and understood that these are
spalled out of the H chondrite. If my memory serves me correctly there
were a few of you real smart guys out there that were adament opponents
of a meteoritic origin at all concerning these tiny irons. A bunch of
us that were in the field finding these little oriented beauties
couldn't understand this position and I was truly starting to doubt
some of the science/scientists. I'm glad it was straightened out and
the truth acknowledged. I don't know if I agree with them getting their
own classification but something needed to be done to acknowledge the
unusual circumstances and unlikely event that created these. That being
said, let's look closely at the irons, they may tell the whole story if
we
can learn to read them.

Rob says they didn't have the opportunity to experience "high altitude,
high velocity ablation." I've posted some more pictures to my
photobucket site. Though they are not the best pic's they do
demonstrate the fact that at least some of these experienced some
serious ablation, from flow lines to roll over lipping, bullet shapes
and BB's. That in my
opinion constitutes high altitude, high velocity ablation. These shapes
did not occur some time after the stone was on the ground and the metal
weathered out, nor did the shapes occur during dark flight, no way no
how.

As far as weathering away over the long period of time since the fall,
I have no answer for that. However, it is a fact that many of the irons
that have been found are smaller than .1 gram. I've found them myself
and I've looked at other peoples finds that are very tiny. Somehow they
are not weathering into oblivion. Perhaps this is another aspect of
these irons that is not yet understood. Some are more weathered than
others. They range in color from gun barrel blue to orange rust, some
are black, others are brown, with different degrees of weathering
apparent.

I believe it's important to know the true answer because if it is a
meteorite it should shed light on the impact pits on Sikhote Alin and
other irons. Some people think that impurities popped out of the iron,
or in the case of Franconia, that chondrules popped out, while others
see a splash as if something impacted it. My little enigma may answer
that question if it is proven to be of extraterrestrial origin. That
would be a contribution to the science.

If the RFSPOD object is a meteorite I think it is imperative that that
be known. I feel an obligation to put it to the test and I'm close to
having a SEM reading. I'll certainly inform the list when the results
come in.

Whatever the result is this has been a positive thread that inspires
people to think and have constructive conversation and debate, what
else could you ask for?

http://s934.photobucket.com/albums/ad190/alienrockfarm/

Best Regards to All
Larry


-----Original Message-----
From: Rob Matson <mojave_meteorites at cox.net>
To: meteorite-list <meteorite-list at meteoritecentral.com>
Sent: Sun, May 9, 2010 3:19 am
Subject: Re: [meteorite-list] FW: Rocks from Space Picture of the Day
-May 8, 2010

Hi All,

Short opinion: manmade.

Reasoning: the inability to produce such a form purely through
atmospheric ablation. Just to remind everyone, all of the
so-called Franconia irons are nothing more than chondritic
iron that has separated from an H-chondrite fall -- either
during flight, or by terrestrial weathering processes on the
ground. Thus it has always bothered me that these irons were
given a separate meteorite name from the ubiquitous H-chondrites
at Franconia from which they derive. If my information is
outdated on this subject, someone please let me know. But many
(most?) of the people I know who have hunted Franconia and
found these irons do not pretend that they are from a separate
iron fall -- they all accept that the iron nuggets were
spalled from an H-chondrite.

So, getting back to Larry's unusual, tiny iron find. If this
iron did not start at the top of the atmospere as a very tiny
piece of iron, there would be no way to ablate it, let alone
punch a hole through it. Since the Franconia irons were once
part of a massive chondritic meteoroid, there was no opportunity
for these irons to experience independent, high altitude, high
velocity ablation. Their ablation history wouldn't have started
until the main H-chondrite body had fragmented on a gigantic
scale (e.g. terminal burst), which of course would have
occurred at comparatively low altitude.

On a final note, the H-chondrite fall at Franconia was not
a recent one. While this part of NW Arizona receives little
seasonal rainfall, I don't imagine that a 0.1-gram piece of
iron could survive more than a century. But a manmade piece
of iron, dropped there in the last 50 years, might possibly
survive terrestrial weathering.

I would love nothing more than for Larry's find to have an
extraterrestrial origin; but the physics and history of finds
at Franconia argue strongly against it.

Best wishes,
Rob

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Received on Sun 09 May 2010 12:05:06 PM PDT