[meteorite-list] When is a fall...?

From: MeteorHntr at aol.com <MeteorHntr_at_meteoritecentral.com>
Date: Mon, 27 Apr 2009 20:38:09 EDT
Message-ID: <cc6.4d5ea9b5.3727a9f1_at_aol.com>

Of course: all Finds did fall at one time. As all Falls were found at one
time.
 
I would think being able to assign a specific date and even a time of day
with some certainty to a meteorite landing is what anchors it into the Fall
category. All others recoveries that are found without the known fall
time end up in the Find category.

I know, some older Falls have vague dates, sometimes only given the month
they fell, but nonetheless an event (seen, heard, felt recorded with
instruments) historically establishes a specific time which the specimen(s) added
to the mass of our planet.

There is some science that would be tied to how long a specimen has been
on Earth, but for the most part, the collecting community is interested in
the falling date for the historic aspect rather than for the possible
scientific aspects.

On such-a-such a date, this happened and a result this certain meteorite
landed on Earth; a Meteorite Fall.
 
Some meteorites are on the edge, such as Cat Mountain. No reports of a
fireball were seen, nor sonic booms heard, but a very fresh meteorite ended up
on a walking path, supposedly that wasn't there the day before. A fall?
Definitely not a Witness Fall. It ends up in the Find category.
 
Waconda, Kansas is so fresh, and probably was a witness fall immediately
recovered. But without any documented witnesses, it too ends up as a "Find."
  Lafayette, is another one on the fence. Found on the shelf at Purdue
University, no date of the fall, where it was found, or who recovered it
exists. But there was a story that a man saw it land while fishing (as I
recall.) It is killer fresh, and few doubt that someone saw in land on a
certain day, but not being able to document more details, it is forever assigned
as a Find.

Steve Arnold
Arkansas



In a message dated 4/27/2009 5:24:00 P.M. Central Daylight Time,
rob_mccafferty at yahoo.com writes:

Falls are surely when recoverable material makes it to the surface.

It would be classified as a "find" if material is recovered but the
fireball was not witnessed. This suggests serendipitous discovery but is
obviously not always the case (Antarctica and hot desert "finds" are the result of
deliverate search efforts but in most cases, the fall obviously occured many
 years ago. The geology of these areas makes sucess more likely, perhaps,
vastly so but it is still a lucky dip).
For normal parts of the world, a search for new finds is one of hope.

It is an "observed fall" if it is eyeballed on the way down.
Following this, searchers KNOW there are samples in a specific area rather
than hope. This improves the chance of recovering a sample tremendously.
I know freshness is important but if it were as easy to discover a new
"find" as it was an "observed fall", the hunters wouldn't feel the need to
descend on each new "observed fall" like a pack of wolves on a wounded caribou
(OK, I know it's still not easy to discover an observed fall but I meant
by comparison, like electromagnetism is easier than quantum electro
dynamics...oh and sorry about the pack of wolves analogy, that makes hunters sound
vicious and bloodlust driven)

I think "fall" has become synonymous with "observed fall" but nobody can
really be bothered to say "observed fall" all the time.


When it's witnessed by photograph or radar but not actually seen, a search
would still be targetted to a specific area determined from the
observation. I'd still be classifying this as an "observed fall".

Some purists may balk at classifying a radar image as "observed" but there
is a precedent (kinda)
Many of Saturn's and Uranus' moons have "Voyager 2" given as their
discoverer. Some, were spotted on images only many weeks after the image was taken
and credit goes to the automated robot rather than the image analyst. I
think this is very much the same thing. If a machine can discover a moon, it
can observe a fall.

Rob Mc
 
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Received on Mon 27 Apr 2009 08:38:09 PM PDT