[meteorite-list] re: Bootids (Quadrantids), 2003 EH1 & St. Marks meteorite

From: Marco Langbroek <marco.langbroek_at_meteoritecentral.com>
Date: Thu Apr 22 10:18:03 2004
Message-ID: <005001c3c93c$c3966520$82c5ea3e_at_HAL>

Hello Dough,

I enjoy this discussion with you, your suggestions are creative. I have
given your new suggestions some thought, but I see two problems.

A large, compact fragment in an earth-crossing orbit similar to that of 2003
EH1 with perihelion close to 1 AU (in essence: this is the Quadrantid stream
orbit) would have a geocentric velocity of 40.2 km/s. That is very high for
a meteorite surviving to be likely. Even a mass of several tons would likely
completely disintegrate in an airburst.

But what really rules out that St. Mark's is related to the Quadrantids &
2003 EH1, is that the Catalogue of Meteorites lists a fall time near 23:00
local time. A fall from the direction of the 2003 EH1 orbit at this location
at this time of the day is impossible, as the radiant is still far below the
horizon. In fact, it barely rises for south Africa, attaining for the fall
locality a maximum
elevation of about 9 degrees only, at 8:40 local time. The radiant rises at
5:40 local time (nearly a quarter of a day after the reported time of fall
of St. Marks) and sets at 11:45 local time, and a fall would only be
possible within this time window.

Cheers,

- Marco

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Marco Langbroek
Dutch Meteor Society (DMS)
Leiden, the Netherlands
52.15896 N, 4.48884 E (WGS 84)

meteorites_at_dmsweb.org
http://home.wanadoo.nl/marco.langbroek
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Received on Tue 23 Dec 2003 05:08:43 AM PST