[meteorite-list] Witnessed fall lunars?still no clear answere

From: Martin Altmann <altmann_at_meteoritecentral.com>
Date: Wed, 8 Sep 2010 18:17:40 +0200
Message-ID: <001101cb4f71$5c330f60$14992e20$_at_de>

Hi

Because the people weren't there, when and where they felt, to witness them.

General fall rates are a topic for its own, they range in the discussion
from a few thousands up to 40,000 falls per year, where a nice stone is
really dropped.

And each year there are recovered from these thousands of falls always only
zero to a dozen.
And only the last 200 years meteorite falls were really noticed.

http://tin.er.usgs.gov/meteor/

Currently the database has 52000 valid & provisional meteorite entries.
Means - I don't know - 36566 form Antarctica, average pairing rate let's say
5, 7300 original falls.
1200 witnessed falls.
2000 or so non-desert finds.
12,000 or so desert finds, let's say pairing rate 3...

So extremely roughly guessed we have stuff from 15,000 different meteorite
falls.


Let's look...
Antarcica 7000+ different fall events - 19 lunaites and 15 Martians.

Oman, where the data are better than with NWA (hopefully not too much
pairings will be artificially created? Switzerland?)
2800 numbers 22 lunaites and 4 Martians

Falls
1200 0 lunaites and 4 Martians


Sooo... observed falls are unsuspicious, regarding the problem that a
lunaite wouldn't be recognized in the field, cause it is too similar to
terrestrial rocks.
Partially Antarctica too as partially the rocks were collected on sheer ice.

Therefrom we can speculate, that lunaites fall much more rarely than
asteroidial meteorites
(id est all the other stuff, without Martians).

Hence they are rare per se.

With finds, well there we see, that from among 100-350 meteorites found and
published meteorites 1 is a lunar.
(Perhaps the ratio is even larger...with the desert finds, ordinary
chondrites often aren't classified at present).

But doesn't matter, that here is totally unscientifical :-)

So.
99% of all meteorites aren't lunars (finds, falls stats)
99.9% of all meteorite falls aren't observed.
Meteorite falls we tend to witness and to report so far only in a tiny
window of 200 years.
1200 witnessed falls we have.


This dairymaid calculation - we say here for a na?ve fallacy -
makes it at least for me plausible,
why we haven't any observed lunar fall yet

and it doesn't exclude that an observed fall could have happened in past
among the 1200 observed ones
and it neither excludes that it will happen in future!

So I think the reason isn't so much a physical one, but it's only: Chance.

Best!
Martin


-----Urspr?ngliche Nachricht-----
Von: meteorite-list-bounces at meteoritecentral.com
[mailto:meteorite-list-bounces at meteoritecentral.com] Im Auftrag von Steve
Dunklee
Gesendet: Mittwoch, 8. September 2010 16:49
An: almitt2 at localnet.com; meteorite-list at meteoritecentral.com
Betreff: Re: [meteorite-list] Witnessed fall lunars?still no clear answere

Hi everyone. You did a good job of thrashing my response without giving an
answere to the original question. Why are there no lunar witnessed falls? DR
kortev did say there are twice as many Martian impacts,which to me is a lot
or many more. Another person questioned if they would have enough velocity
to be seen which is a verry good point because some would reach terminal
velocity much sooner than an object from mars or the astroid belt. The
amount of time recovered lunars take to reach earth has been said to be the
same as mars meteorites. I am beginning to believe it may be a matter of
recognition. A lunar would reach terminal velocity 20 or more miles up and
fall without making a sound. And if it did make a sound the person finding
it would do everyones "is it a meteorite" test. Brown or green crust? Doesnt
stick to a magnet.vesicles on the crust. Must not be a meteorite. And what
size does it take to launch a rock from the moon?small would do it.
 Cheers Steve


      

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Received on Wed 08 Sep 2010 12:17:40 PM PDT