[meteorite-list] ANOTHER QUESTION

[Sterling K. Webb]

Hi, Chris, List,

> most all come from the Zone. 
> But a handful don't.

    Burning curiosity! 
    Where do the handful come from?
    One general class of orbits or a little
something from everywhere?


Sterling K. Webb
--------------------------------------------------------------
----- Original Message ----- 
From: "Chris Peterson" <clp at alumni.caltech.edu>
To: <meteorite-list at meteoritecentral.com>
Sent: Tuesday, November 21, 2006 1:18 AM
Subject: Re: [meteorite-list] ANOTHER QUESTION


> Sterling-
> 
> What began with a single camera in Czechoslovakia in 1958 continues 
> today as the European Fireball Network, and has been in pretty 
> continuous operation. In addition to Pribram (not Pribeam), it also 
> tracked Neuschwanstein in 2002, resulting in the recovery of at least 
> three pieces. Not all networks shut down.
> 
> The original Canadian and American efforts failed due to high costs 
> because they were film based, and required continuous active 
> maintenance. The Czech network was also film based, but I assume the 
> economics of its operation during the Cold War were different than in 
> the west.
> 
> Modern networks are on the rise. We've had ours running over five years 
> now. Sandia has one. There are a couple in Canada. More individuals are 
> setting up one or two cameras. Video and computers is what makes this 
> possible- it is no longer expensive to run a network. You no longer have 
> to send a slave... I mean grad student out every day to change the film 
> in several stations. No manual processing, practically no work at all. 
> You don't need radar or spectrographs.
> 
> We still don't have a recovery (although one is inevitable), but I've 
> recovered the orbits for a good many fireballs. Not surprisingly, most 
> all come from the Zone. But a handful don't.
> 
> Chris
> 
> *****************************************
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
> 
> 
> ----- Original Message ----- 
> From: "Sterling K. Webb" <sterling_k_webb at sbcglobal.net>
> To: "Gerald Flaherty" <grf2 at verizon.net>; "Chris Peterson" 
> <clp at alumni.caltech.edu>; "Jeff Kuyken" <info at meteorites.com.au>; 
> <meteorite-list at meteoritecentral.com>
> Sent: Monday, November 20, 2006 11:31 PM
> Subject: Re: [meteorite-list] ANOTHER QUESTION
> 
> 
>> Hi, Gerry, List,
>>
>>
>>> WHERE DO THEY
>>> COME FROM...???
>>
>>    Despite having so many meteorite falls
>> observed, we have not enough information
>> from even many observations to determine
>> orbits for them. For that, you need a network
>> of full time observing stations with recording
>> radar and automatic cameras running all night
>> and spectrographs... expensive and elaborate.
>>    There have been such networks set up in
>> the past, but were eventually shut down due
>> to great cost and limited results. The first such
>> network was set up in Czechoslovakia and, in
>> 1959, tracked the recovered PRIBEAM. It had
>> aphelion at 4.05 AU (the Hilda family of asteroids)
>> and perihelion at 0.79 (Venus) with eccentricity of
>> 0.674. In all the other years this network ran, it
>> only successfully tracked one other item, an iron
>> which hit German forest country and was never
>> recovered.
>>    In the 1970's the Prairie Network in the USA
>> was established, which tracked and led to the
>> recovery of LOST CITY. Although it tracked
>> another dozen or so re-entries that probably
>> brought in a surviving chunk, none were ever
>> found. LOST CITY had an aphelion of 2.42
>> AU (densest past of the Zone) and a perihelion
>> of 0.97 AU (the Earth) with an eccentricity of
>> 0.417. It too was shut down due to "costs."
>> And the Canadian network (MORP?) tracked
>> INNISFREE to recovery, but never recovered
>> another.
>>    All three of these spacerocks had aphelia
>> deep in the asteroid zone, all at places where
>> Jupiter could strongly perturb them. The great
>> meteoriticist Krinov worked out a pretty good
>> orbit for Sikhote-Alin that showed it came from
>> the Zone. The Great Grazer of 1972 (the Jackson
>> Hole Bolide) had several orbits worked out, but
>> all of them have it coming from the Zone.
>>    Face it, it's a bad neighborhood! It's like, they're
>> standing on an overpass and dropping rocks onto
>> the windshields of passing planets! Of course,
>> three examples of well-determined orbits are hardly
>> "proof" when there are many thousands of meteorites.
>> But on the other hand, if you rolled three sevens in
>> a row at craps, wouldn't you be surprised? (And,
>> if you CAN roll three sevens in a row at craps, we
>> need to talk...)
>>    So, we blythely assume most of them come from
>> The Zone. (My apologies for calling the Great Grazer
>> a "bolide," but magnitude -25 or -26, hey! You need
>> a special name! Especialy since it was nice enough
>> to miss us...)
>>
>>
>> Sterling K. Webb
> 
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