[meteorite-list] Grimsby family shows off visitor from space

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From: Jeff Grossman <jgrossman_at_meteoritecentral.com>
Date: Fri, 16 Oct 2009 23:38:30 -0400
Message-ID: <OFDE81ECC6.36478EFA-ON85257652.00140C0A_at_usgs.gov>

Sterling's calculation was on 12/9/2000. I think I pointed out back
then that the calculation he did is not for the total number of falls
per year... it is the total number of stones that fall per year. At
least that is what it seems to me. I'm not sure what the average
number of stones per fall is, but it must be >10 (Holbrook alone
brings the average to over 10 even if all the other known falls had
only 1). So I'd like to challenge him to recalculate the number of
falls with this in mind.

Jeff

At 09:35 PM 10/16/2009, Sterling K. Webb wrote:
>Hi, Ted, Greg, Gary, List,
>
>>Are we onto something here?
>
> Well, yes, we are. One data point we'd really
>like to have is how many meteorites fall yer year,
>the annual flux. To determine it, all we have to do
>is to stake out a patch of perfectly cleared planet
>and recover and count all the meteorites that fall
>there for several centuries or millennia.
>
> Not so convenient, though... Since the fall of
>meteorites is a random process, the total area of
>the "sampling patch" does not have to be contiguous.
>It can be many millions of smaller patches scattered
>all over the planet. You can even move them around
>randomly -- doesn't affect the accuracy of the final
>calculation of the "impact cross-section of the Earth."
>
> That "sampling patch" is CARS (and trucks, and
>other vehicles). We can get a good idea of the number
>of them year by year. We can closely estimate the mean
>geometric cross-section of the targets. And the "lossiness"
>of the experimental data is reduced by the fact that
>people tend to notice when their shiny pickup truck is
>holed by a meteorite!
>
> I did all that sophisticated arithmetic ten years ago
>and published a paper with the results, exclusively to
>this List (which is why nobody's heard of it). The figure
>widely published back them was the MORP rate of
>25,530 falls per year, although Zolenski and Wells
>argued in 1988 that it could be much higher:
>http://adsabs.harvard.edu/full/1990amss.work...91Z
>
> The fall rate that I calculated from this method was
>approximately 78,000 falls per yesr with a possible error
>of 25,000 either way. So few cars get hit. Rob Matson
>chimed in that his personal estimate was a minimum
>of 80,000 per annum. From that rate, I predicted (in1
>Dec., 1999) that there would be at least one car hit in
>the decade 2000-2009 and a better-than-50% chance
>it would be two.
>
> It seems to be two (and just in time).
>
> That was Novemeber or December of 1999, and as we
>close out 2009, Grimsby appears to be the second (Worden
>in 2002 was the first). Getafe (mentioned earlier) is classed
>politely as a pseudometeorite. I allowed for the increase in
>the number of cars in time, based on the 1990's sales rate
>increases.
>.
> I thought that this idea of mine was, as they say,
>"methodologically sweet." I was unreasonably proud of
>being so clever until I discovered this paper by Ben Hur
>Wilson, entitled "A method of estimating the absolute
>number of meteorites," published in 1940 in the old
>POPULAR ASTRONOMY, Vol. 48 (p. 366):
>http://adsabs.harvard.edu/full/1940PA.....48..366W
>which contains the essence of the method. A new
>idea is hard to come by.
>
> However, Wilson based his numbers on observed falls
>in specific areas which, in 1940, was scanty data. He
>concluded there were 250 falls per year for the entire
>planet!
>
> Nininger disagreed violently with this; he thought
>there were 500 meteorite falls per year (between 1 gram
>and 1 kilogram), perhaps as many as 1,000 and cited
>some of his own statistics from Kansas finds.
>
> It seems that the more data we get, the faster they fall.
>
>
>Sterling K. Webb
>---------------------------------------------------------------------------
>----- Original Message ----- From: "Ted Bunch" <tbear1 at cableone.net>
>To: "Gary Fujihara" <fujmon at mac.com>; "Greg Stanley"
><stanleygregr at hotmail.com>
>Cc: <meteorite-list at meteoritecentral.com>
>Sent: Friday, October 16, 2009 4:47 PM
>Subject: Re: [meteorite-list] Grimsby family shows off visitor from space
>
>
>>Apparently, meteorites seek out cars much like tornadoes seek out trailer
>>parks. Are we onto something here?
>>
>>Ted
>>
>>
>>On 10/16/09 11:31 AM, "Gary Fujihara" <fujmon at mac.com> wrote:
>>
>>>Wow! Another car-smashing hammer like Bendl (1938), Peekskill (1992),
>>>Getafe (1994)!
>>>
>>>gary
>>>
>>>On Oct 16, 2009, at 8:22 AM, Greg Stanley wrote:
>>>
>>>>
>>>>
>>>>All:
>>>>
>>>>Take a look. Looks like the real deal. A hammer!
>>>>
>>>>Greg S.
>>>>
>>>>
>>>>http://beta.stcatharinesstandard.ca/ArticleDisplay.aspx?e=2133932
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>Yvonne and Tony Garchinski are the proud new owners of five
>>>>tiny meteorite fragments.
>>>>
>>>>They also have a new windshield, after the space rock smashed into
>>>>their
>>>>Pathfinder three weeks ago.
>>>>
>>>>"I thought it was vandalism, for sure," said Tony Friday as dozens
>>>>of reporters converged on his west Grismby home. "Who thinks a
>>>>meteorite
>>>>is going to crash-land on your car?"
>>>>
>>>>The golf ball-sized fragment is likely part of a larger meteorite
>>>>that lit
>>>>up the skies of southern Ontario
>>>>Sept. 25.
>>>>
>>>>The fireball was first picked up by cameras operated by the
>>>>University of
>>>>Western Ontario's physics and astronomy department 100 kilometres
>>>>above Guelph
>>>>as it streaked southeastward at a speed of about 75,000 kilometres
>>>>per hour.
>>>>
>>>>Scientists released that footage Oct. 7 and began searching a
>>>>12-square-kilometre area near Grimsby
>>>>where they thought the meteor fell.
>>>>
>>>>Only after seeing the footage on television did the Grimsby family
>>>>realize their car-bashing
>>>>vandal might instead be an alien invader.
>>>>
>>>>"We filed a police report and everything," said a laughing Yvonne,
>>>>who held out the tiny silver and black space rock pieces for
>>>>reporters to see
>>>>Friday.
>>>>
>>>>After reading up on the meteorite search, Yvonne called Phil
>>>>McCausland, an
>>>>astrophysicist at the University
>>>>of Western Ontario, who
>>>>verified the tiny rocks were out of this world.
>>>>
>>>>"They're probably the oldest rocks that you or I or anyone else are
>>>>every going to hold," McCausland said. "it's pretty exciting."
>>>>
>>>>The Garchinskis own the window-smashing space pebbles, but they've
>>>>agreed to
>>>>loan them to university researchers for three months.
>>>>
>>>>
>>>>
>>>>_________________________________________________________________
>>>>Hotmail: Powerful Free email with security by Microsoft.
>>>>http://clk.atdmt.com/GBL/go/171222986/direct/01/
>>>>______________________________________________
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>>>>Meteorite-list at meteoritecentral.com
>>>>http://six.pairlist.net/mailman/listinfo/meteorite-list
>>>
>>>Gary Fujihara
>>>AstroDay Institute
>>>105 Puhili Place, Hilo, HI 96720
>>>(808) 640-9161, fujmon at mac.com
>>>http://astroday.net
>>>
>>>______________________________________________
>>>http://www.meteoritecentral.com
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>>>Meteorite-list at meteoritecentral.com
>>>http://six.pairlist.net/mailman/listinfo/meteorite-list
>>
>>
>>______________________________________________
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>>http://six.pairlist.net/mailman/listinfo/meteorite-list
>
>______________________________________________
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Dr. Jeffrey N. Grossman phone: (703) 648-6184
US Geological Survey fax: (703) 648-6383
954 National Center
Reston, VA 20192, USA
Received on Fri 16 Oct 2009 11:38:30 PM PDT

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