(meteorobs) Fireball questions

[Roberto G.]

From: "Robert Verish" <bolidechaser at yahoo.com>
To: "Meteor Observers" <meteorobs at meteorobs.org>
Sent: Monday, June 21, 2004 8:59 PM
Subject: (meteorobs) Fireball questions


> ---------- Forward Message -----------
> 
> FW:  Fireball questions
> vincent J <meteorh3_6 at hotmail.com> 
> Wed Jun 16 14:02:39 EDT 2004 
> 
> Hello List,
> 
> I'm working on new page of my website. This page
> concerns fireball explosions.
> 
> Just some questions:
> When a fireball explodes and creates a sonic (shock)
> wave observed at seismic stations ++++ can we suppose
> that meteorites can be found on the ground?

Only sometime, not in all time. For exemple the bolid 
of Lugo, Northern of Italy (19 January 1993) was recorded 
by 7 sismic stations but nothing fell on the ground (12 
kilotons of power). Only a bolid between 100 as the 
Full Moon do a meteorite.

> At which altitude does a normal bolide "explode", or
> produce an audible sonic boom?

The audible sonic boom occur only when the meteor has
not more of 50 Km in hight, in the other case the
sound go toward the space (in theory).

> I'm looking for  "witness map" showing a bolide path,
> and witness position with all observations (trajectory
> and noise). 

You must reminder that it can to be too silent area,
in general the sound it's recorded better exactly
under the traiectory of the bolid.

> 
> Thank you and best regards, 
> Vincent JACQUES

Best greetings.
Roberto Gorelli