[meteorite-list] Revovered(Recovered) weight of CAMPO

From: MexicoDoug_at_aol.com <MexicoDoug_at_meteoritecentral.com>
Date: Thu Feb 17 21:31:52 2005
Message-ID: <7277DEBC.3A3E27F6.0BFED528_at_aol.com>

Dave, Mike, List,

I like Dave's suggestion to get a handle on the sizes of these monsters. Another demented way if you don't have a local quarry or metal crushing yard nearby, is just to multiply your body weight by 8 for irons, or 3 to 4 for ordinary chondrites. So a nickel-iron meteorite the size of a 180 pound man (82 kilos) would be about 1440 pounds (650 kilos).

This is because iron meteorites are 8 times as dense as water. People are mostly water (that's why many can float or sink depending on how deep you breathe in.).

People tend to think they are bigger than they reality are (references: Le Petit Prince), so telling a group of kids to assume the fetal (cannon-ball dive) position...a 90 pound kid is the same size as a 325 kilogram iron - a very respectable main mass for many iron meteorites.

For Campo del Cielo, 500-800 kg of apparently new material appears on the market monthly, the size of a 180 pound man give or take 25%. Conservatively, that's 6 metric tons a year increase lately. So 100 tons total recovered so far is probably a decent practical estimate as you can get. And clearly has Campo probably as the largest combined weight meteorite recovery known, and a beautiful one at that, although it doesn't hold the record for the size of a single individual.

And when dealing with ordinary chondrites, just halve the iron weights to get in the ballpark of the ordinary chondrites.

If one wanted to involve a classroom in the appreciation of the size and weight of wondrous find like the Campo del Cielo material, a class of thirty kids (fifteen 180 pound adults)packed together like sardines in a can would be the human volume equivalent of a 10 ton iron meteorite. So there is about as much Campo recovered as 150 people packed together and it increases by one each month. (For kids, each month it grows two kid's sizes worth.) And then there is the famous picture of Bob Haag doing an Atlas pose (how I interpret that blissful photo), holding the fifty times larger and 400 times heavier 33,600 (?) kg main mass of Campo del Cielo on his back, which would be a superb addition for scaling in any exhibit.
Saludos, Doug

Dave Freeman wrote:

Dear Mike, List;
For a weight vs. mass comparison of piles of meteorites, go to your local rock quarry or aggregate plant and ponder a bit. Irons would be easier ascertained at a steel or scrap yard but for common (now there's a relative term) chondrites would be approximately equal to a lighter mass rock but for size~mass estimates, try a quarry and see dump trucks and front end loaders and ask about weight of specific rocks.
Now is a slower season for most crusher operators/quarry operations and may provide a great excuse for a short local field trip. There are scales in engineering books to convert different materials from limestone (lighter wt.) to quartz (heavier wt.) to iron ores (much heavier wt.) so if you see a pile of a known material, you can use some math to get the tons in a pile. I can dig up a couple of formulas from
my Pocket Ref by Thomas J. Glover (found in Ace Hardware stores nation wide for around $10). Don't leave home with out it. Best main masses, Dave F.

meteoriteplaya_at_comcast.net wrote:

>Hi Bernd, Sara & List
>
>One point I would like to make is that all anyone can do is estimate a number as Bernd has done. In writing the main section of "Meteorites from A to Z" I include TKW. I wanted to try to come up with numbers that were up to date. For Gibeon I added the TKW (based on adding distributions) of the Catalogue of 33000 kg and figured at least 17000 kg more had been recovered and were not reported. So I used the number 50000+ kg.
>
>For Campo del Cielo I have 10000+ kg but already had a note to change to 50000+ kg for the next edition. My guess is it is over 60000 kg. If I were setting up a display I would recommend that one note it is an estimate no matter what number they use. For example 50 t estimated or ~ 50 t or >50 tonnes.
>
>You might also remember the most people me included have no idea of what 10000 kg of a meteorite is in terms of size. So being off by 10000 kg or more does not mean too much. Probably the only reason to be as accurate as possible is to create a list of the largest falls by weight.
>
>In case anyone is interested I have created a list of the largest 15 individuals by weight for the iron meteorites. It includes lots of pictures. Here is the URL if you want to check it out;
>http://jensenmeteorites.com/largestmeteorites.htm
>
>Hope that helps.
>
>Mike
>--
>Mike Jensen IMCA 4264
>Bill Jensen IMCA 2359
>Jensen Meteorites
>16730 E Ada PL
>Aurora, CO 80017-3137
>303-337-4361
>
>
>>Dave Freeman wrote:
>>
>>>In my catalogue, I see no TKW for my favorite Gibeon iron
>>>
>>Hello All,
>>
>>There is a table on page 592 of Buchwald's trilogy. Vagn Buchwald
>>wrote that the total weight of the 77 specimens listed in the table
>>was 21,000 kg. As many more masses have been found to date, we can
>>assume a TKW of at least 21 tons!
>>
>>Reference:
>>
>>BUCHWALD V.F. (1975) Handbook of Iron Meteorites, Vol. 2, pp. 584-593).
>>
>>
>>Best wishes,
>>
>>Bernd
>>
Received on Thu 17 Feb 2005 09:31:40 PM PST