[meteorite-list] Pribram and april 6 bolide

From: Marco Langbroek <marco.langbroek_at_meteoritecentral.com>
Date: Thu Apr 22 09:50:28 2004
Message-ID: <000f01c1e7df$66a1fd60$d4d386c2_at_latitude>

Message: 9
Date: Thu, 18 Apr 2002 22:47:57 +0200
From: Bernd Pauli HD <bernd.pauli_at_lehrer1.rz.uni-karlsruhe.de>
To: meteorite-list <meteorite-list_at_meteoritecentral.com>
Subject: [meteorite-list] Large Bolide of April 6


> Hello All!
>
> Let's have a look at the respective velocities and orbital elements:

[snip]

> A truly striking resemblance !!!
>
> Bernd

And indeed it is!! A formal way to express the similarity of two orbits, is
by way of Drummond's D' criterion, a modified version of the
Southworth-Hawkins D criterion. This D' criterion weights the different
orbital elements and expresses the degree of similarity in a value. If the
D' value comes out smaller than 0.105, the orbits compare well and
association can be considered.
I just ran a D' criterion calculation for Pribram and EN 060402. It yields a
D' value of 0.007 - an extremely fine value!!

By the way, there is another meteorite orbit which associates with the
Pribram orbit (see [1]). That is the orbit of the Glanerbrug meteorite of
April 7, 1990. Pribram and Glanerbrug yield a D' value of 0.099 - (much)
larger than Pribram and EN 060402 but still not bad. Glanerbrug is an L/LL
breccia. The orbit is derived from a large number of visual observations and
thus does not have the accuracy of Pribram or EN 060402. Uncertainties in
the Glanerbrug orbit are most likely towards an in reality smaller value for
semi-major axis and inclination - in which cases the D' value actually
becomes better than 0.099, not worse.

- Marco Langbroek

[1] Langbroek M., Radiant (J. of the Dutch Meteor Society) 23:4 (September
2001), p. 76-78
Received on Fri 19 Apr 2002 04:17:28 PM PDT