[meteorite-list] Discover article - annual fall rate

From: Matson, Robert <ROBERT.D.MATSON_at_meteoritecentral.com>
Date: Thu Apr 22 09:41:12 2004
Message-ID: <AF564D2B9D91D411B9FE00508BF1C8692C5F6C_at_US-Torrance.mail.saic.com>

Hi Kelly,

> Like you, I sort of jumped up out my chair and fumed for a while
> after reading that statement. I have seen the 500 per year figure
> given in other sources, which is one reason I posted my method of
> calculating falls, because 500 per year is a ridiculous figure.

I'd love to know where that 500/year figure originally came from,
because if what you say is true, this absurd number has established
credence only through its repetition.

> His methodology depends on establishing an accurate age for all
> the finds in a given geographical area, thus determining the time
> span covered by those finds, and working backwards to set a fall
> rate that will account for that number of finds. This method of
> course cannot detect how many meteorites are lost, eroded,
> degraded, destroyed, unrecovered, deposited elsewhere, and so
> forth.

I wonder what area or areas of the earth he used for this
statistical sampling analysis.

> What was important about his work is that his measured ages
> show that the fall rate is essentially constant over a long
> time span.

That was worthwhile work, and was of course his main intent.
It was just unfortunate that such an erroneous annual fall
rate figure was mentioned in the middle of the sentence.
The strength of his conclusion is tainted by the glaring
error.

> However, it is essentially unfair to judge any scientific argument
> by its paraphase in a popular journal.

Excellent point. History has shown time and again that paraphrasing
science for popular consumption is an error-prone endeavor.

> So, I started hunting for his original article. It is not
> available on-line (too old). I have found a library source
> for it but have not made the 60-mile trek to their basement
> to xerox it so I can properly and responsibly attack that
> silly 500 per year figure.

I look forward to hearing what you find out. At only 500 meteorites
per year globally, they would need to survive for 400,000 years to
support a surface density of just 1 meteorite per square mile.

Cheers,
Rob
Received on Sun 25 Feb 2001 05:16:04 PM PST