[meteorite-list] Park Forest retardation point

From: Matson, Robert <ROBERT.D.MATSON_at_meteoritecentral.com>
Date: Thu Apr 22 10:22:38 2004
Message-ID: <AF564D2B9D91D411B9FE00508BF1C86901B4EA9F_at_US-Torrance.mail.saic.com>

Hi List,

I'm with Mike Farmer and Frank Prochaska on this one: it simply
isn't possible that Park Forest was still luminous at 7000'
altitude -- there must be an alternate explanation for the
visual/video observations or interpretation of the cloud deck.

Ignoring for the moment the argument that nearly all comparable
meteors reach their retardation point at altitudes over 8 times
higher than this, consider the ramifications of a meteoroid
still barrelling along at 7000' at a speed high enough to
ionize the air. Clearly the velocity is still supersonic,
which means you're going to have sonic booms on the ground
less than 7 seconds later. I've heard no reports that sonic
booms came so close in time after the light effects.

Furthermore, stones didn't start hitting the ground until
minutes later; even if you allow for nearly instantaneous
deceleration to a low terminal velocity like 150 meters/sec,
you're still going to have meteorites on the ground less
than 15 seconds after "lights out". So you see -- the math
simply doesn't add up.

--Rob
Received on Sat 14 Jun 2003 02:29:13 PM PDT