[Prev][Next][Index][Thread]

(meteorobs) Re: Meteorite over Greenland 091297- English. (fwd)



---------- Doorgestuurd bericht ----------
Date: Sat, 20 Dec 1997 13:16:08 +0100 (CET)
From: Marco Langbroek <marcolan@stad.dsldot nl>
To: Keld Rasmussen <keld-rasmussen@email.dk>
Cc: delpsurf@cistrondot nl, Casper ter Kuile <pegasoft@cc.ruudot nl>,
    Peter Jenniskens <peter@max.arc.nasadot gov>, kuiper@knmidot nl
Subject: Re: Meteorite over Greenland 091297- English.

Op Fri, 19 Dec 1997, Keld Rasmussen schreef:

Hello Keld,

Below descriptions of sound and aerthquake-like phenomena are consistent 
with a sonic boom, looking at the mentioned time-lapse of 3-4 minutes. A 
real earthquake through impact would have arrived much quicker after the 
fireball (waves in solids move at about 3-6 km/s, while shockwaves in air 
(sonic booms) move at 300 m/s, much slower). Sonic booms are regular 
phenomena with bright fireballs. They originate beause a meteoroid 
penetrating into the lower 40 km of atmosphere creates a shockwave 
because of its supersonic speeds at that moment, combined with the object 
itself slowing down.
The mentioning of more than one fireball is interersting. Perhaps he did 
see only the end of the trajectory, and the account relates to 
fragmentation at the end. That can aid survival of fragments.

As far as I can judge now, this must have been a fireball near -15, 
perhaps with sonic boom and terminal fragmentation. This could mean that 
some meteorite fragments can have survived. Yet, in honesty, it is 
becoming clear now I think that this is NOT a very large impact, but 
rather a possible meteorite impact of average size.

Marco Langbroek (DMS)



> In the last few days we have spent most of our time collecting new
> eyewitness, and dokumentation.
> Our latest investigation have shown soundphenomen and small earthcrake.
> Read this eyewitnes rapports
> 
> 
> ********
> 
> Kommunefogedafløser Kristen Johnsen, Fiskenæsset, (South of Nuuk), was on
> the 091297 0510 on the toilet, when he felt an earthcracke. Duration about
> 1 sec. In the same time he heard an eksplosion. His vife and grandchild
> wake up, and the child bagan to cry. 
> KJ thought that it vas a gseksplotion.
> 
> ********
> 
> Jæcob Møller, fiskenæsset, (South of Nuuk), was in his bed, from where
> there are wiev to souht through a window. He saw some (more than 1)
> fireball passing through his sight of view. He was shure that there was
> more than 1 ball.
> After apx 3-4 min he felt an earthchrake and in the same time an
> eksplosion.
> 
> ********
> 
> Isak Olsen, Akkunnaaq, (ca 500 km nord for Nuuk)stod at the 091297 051
> X in open air, ant looking at north. He saw at light phenomen in duration 1
> sec. He did not see any fireball.
> 
> ********
> 
> 
> I hope my insufficient english is better than danish you may not
> understand.
> 

It is sufficient enough. Thanks for communicating the translated accounts! 

> Source and interview by:
> 
> Keld Rasmussen, Københavns Astronomiske Forening.
> keld-rasmussen@email.dk
> tlf:     45 888853 (incl. fax)
> mobil 40 361502
> 
> Look at the home page of Københavns Astronomiske Forening.
> http://www2.dk-online.dk/users/hpersson/kaf.htm
> 
> 
>
Follow-Ups: