[meteorite-list] Closure on the Lancaster, PA Event of 11-18-00

[E.L. Jones]

Hello List,

The short version:  The impact was not meteoric but from an explosive
device.

The long version: This was a good practice for recovery of the real
thing.

BackGround:
Before Thanksgiving Holidays  there was a news report and 
internet email notice that a possible meteorite had landed on 
a car in Lancaster Pennsylvania.  After many delays, we 
dissected the dash of the car in Lancaster, PA  on Tuesday  
night which had a peculiar hole in its windshield.  It had its 
windshield and dashboard disrupted --coincidentally-- during 
the Leonids shower around 3 AM (EDT) local the Morning of 
18 Nov.  The proximity to a fireball sighting headed vertically 
down over Lancaster and shape of the damage raised 
suspicion that this might have been a meteorite impact.  
Initial inspection via various local Police and Fire personnel 
failed to determine a positive identification to the
cause.  Being local to the area and having the most interest, 
it seems, I was invited to participate in the search.

Search:
I joined the car owner, his family , and local planetarium 
personnel to see if we could determine the cause of the 
damage. An external and internal scan did not produce 
any large pieces of foreign material.  I conducted a scan 
with a magnifier over a portion of the windshield took
some samples of several magnetically attractive, dark shards.  
I looked at them under my stereo microscope and they 
appeared to be shards of tar/pitch -which has a glass-like, 
conchoidal fracture. The dash cover had been removed,  
it too, showed no clearly meteoritic fragments.

Not finding anything  meteoritic we moved to the inside.  
The car's windshield and dashboard had been penetrated 
by an approximately 75-90° down-angled force.  
A magnet probe into the well yielded nothing and hopes 
of finding a meteorite were fading,  if not confounding-- there
were no clear  clues either way. Striations on the chrome 
trim but not on the windshield were suspicious and later 
would be a contrasting clue.

After enlarging the opening in the dash to gain access into 
the baffles of the heater core housing, we located what 
appeared to be a crust-less fragment of a bluish-gray  
material with tiny protruding "chondrule-sized" 
bumps-- not unlike the Zag specimens I had brought
along for making field comparisons.  The brief moment 
of suppressed excitement faded as the tweezers confirmed 
this was a sealant foam and not a wedged meteorite in spite 
of the appearance.  The whole floor of the compartment was 
covered in sand-sized, glass particles. In fact, much of
it looked just like mineral sand. At this point I was skeptical 
that we had a meteorite but I could not yet rule out a very 
friable, high olivine, low metallic meteorite. So we continued 
looking and taking samples of the debris.

When extracting the tweezers they dislodged  fragments 
of the culprit. The unmistakable components* of a pyrotechnic 
in the Commercial Pyrotechnic class, surfaced out of the sand.  
It still had the trace odor of a burned composition like flash 
powder or black powder. A minute particle of tar removed 
from the windshield also tends to support that this was a 
sealant used to waterproof the explosive.  The striations
apparently came from the parts of the windshield wiper sheared 
away by the blast and not mineral scratches. All the clues 
came together to confirm that this was an explosive and not 
a meteorite impact.

I participated in post search newspaper interview as to what 
was found, why it was a legitimate event to explore, the 
common misconceptions about meteorites, and the need 
for public involvement in locating meteorites and bringing 
them into science. I also hope we raised awareness of the 
1995 New Holland, PA Fireball from which a meteorite should 
have dropped but was never found.

Lessons Learned:
I thought we did a good methodical approach-- avoiding  
contamination, preserving clues and going slow.  Having the 
right tools for looking into crevices-- telescoping magnet, 
long tweezers, gooseneck flashlight, inspection mirrors, 
lots of swabs and poly bags-- went a long way at keeping the 
search clean.  It was a good hands on opportunity for me to
expand my search techniques and to compare and contrast 
the tell-tale clues of chemical and kinetic produced damage. 
( Add to that list survey flags and shovels in case it is over 
your creel size)

Everyone uses common words and we tend to interpret them 
within our own frame of experience.  This tends to confuse 
investigators and raise speculation.  It is important in 
interviewing witnesses to bracket their statements between 
extremes or contrasting options to make sure you are 
accurately envisioning the witness's" real "experience.  
For example I did not see the "burning and searing" which 
was first described in email reports.  What I did see was
normal "shearing" and fractures in the windshield and 
stretching of the plastic layer in the safety glass.  I had to ask 
several times what the "impact" sounded like.  I 
finally asked was it a "kaboom" or a "kuthump"....I
was told it sounded just like a car crash--like a transformer exploding!
.... At this point I knew we were talking about a "Kaboom" and not the
"Kuthump"-- A distinction which is important in accurate identification
between a chemical blast and a kinetic crash.  My advice is 
to be aware of this quirk in the manner people describe 
things.  Do not reach an early conclusion because they 
have used a word or description  which most of the time will 
be slightly but distinctly different from your use of the
terms. Check'em ALL out.---Even "trained" observers 
can be the worse culprits!

All persons reporting a possible meteorite are not hoaxers or
unsophisticated or unlearned people. This family was sincerely
interested in finding the truth and not just finding a meteorite. 
This did pique their interest in meteorites and I anticipate they
will soon join the list and the hobby.

Finally,  for a long while I have wanted to challenge the use of
regmaglypts in our guides to discovering meteorites... The term
is not described or illustrated sufficiently and meteorites tend
to be more smooth than bumpy. We really need to go revisit
the way we tell the public how to identify meteorites.  I get 
photos frequently and can see how people reach the conclusion
that what they have is a "meteorite" when it is
clearly not in the photo it matches some of the description.

Perhaps soon we can talk about the contents of a 
recovery/investigators kit.

Regards,
Elton

*Because of a police investigation I was requested to refrain from a
full disclosure.