[meteorite-list] Annual Influx Rate and Average Velocity

From: Michael Gilmer <meteoritemike_at_meteoritecentral.com>
Date: Tue, 23 Aug 2011 18:55:49 -0400
Message-ID: <CAKBPJW9J0tEih5_oxz2UXyNv1sd01XfP0QB3ZpcO9CnJTc4_1g_at_mail.gmail.com>

Hi Robert and List,

I'm not sure if this will help or not, but here is a break-down of all
official witnessed falls going back to 2000. There is a worldwide
average of about 5.5 witnessed falls per year that will be officially
recognized by the Meteoritical Society. Of course, this does not take
into account the majority of falls that go unnoticed and undetected.

http://www.galactic-stone.com/pages/falls

Here is a supplement to that page. It was written in December of
2010, so the statistics and numbers used in the article are dated to
that time. Although, nothing unexpected (in trends) has happened
since then, so the conclusions are about the same.

http://www.galactic-stone.com/pages/20falls

Best regards,

MikeG

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On 8/23/11, Chris Peterson <clp at alumni.caltech.edu> wrote:
> Simple mathematics requires that any particular meteoroid class will
> have "one average velocity". But the standard deviation is huge! It
> doesn't matter whether you are talking about dust, pebbles, boulders, or
> asteroids: the body will have an orbital velocity where it crosses
> Earth's orbit that depends on the eccentricity of the orbit (and there
> is a very wide range, from circular to slightly hyperbolic). The actual
> impact velocity is further determined by the inclination, whether the
> orbit is prograde or retrograde, and by Earth's axial rotation. So I
> don't think that there is much value to the idea of an "average"
> meteoroid velocity unless you break down your categories much finer.
>
> Chris
>
> *******************************
> Chris L Peterson
> Cloudbait Observatory
> http://www.cloudbait.com
>
> On 8/23/2011 2:22 PM, Robert Beauford wrote:
>> I need a decent estimate of average annual meteorite influx rate (total
>> mass at all scales per year) and I'm not sure who has done the best and
>> most recent job.
>> Can anyone suggest a source?
>> Also, does anyone have any idea whether anyone has worked out a meaningful
>> average speed (from real data) for inbound objects?
>> I suspect that everything from pebble size to large masses have one
>> average velocity and that dust has a different average velocity.
>> Any insights would be greatly appreciated.
>> Thanks,
>> Robert Beauford
>
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Received on Tue 23 Aug 2011 06:55:49 PM PDT