[meteorite-list] Crash Boom Bang: City Killers & 2008 TC3

[Chris Peterson]

I expect when they said objects 6 feet across don't make it to the ground, 
they meant they don't make it to the ground carrying cosmic velocity. There 
doesn't seem to be any obvious limit on the size of parent body that can 
produce meteorites; that depends on the dynamics of the object in the 
atmosphere.

Calculations suggest that an object needs to be 8-10 meters across to make 
it to the ground still carrying some of its original velocity. No doubt 
there's some variation there, depending on composition and dynamics, but the 
estimate is probably a reasonable generalization.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message ----- 
From: "Meteorites USA" <eric at meteoritesusa.com>
To: <meteorite-list at meteoritecentral.com>
Sent: Wednesday, April 29, 2009 10:36 AM
Subject: [meteorite-list] Crash Boom Bang: City Killers & 2008 TC3


> Hi all,
>
> Are you ready for the big one? It's a matter of when, not if, a city 
> killer will strike. What will this do for science, and I hate to sound 
> morbid, but the meteorite business in general?
>
> http://www.usnews.com/articles/science/2009/04/29/new-mexico-scientist-part-of-team-tracking-asteroids.html
>
> According to the article in US News :
>
> "...Space rocks of that size, about 6 feet across, typically hit Earth a 
> few times each year, usually exploding high in the atmosphere with no 
> advance warning..."
>
> "...Rocks that size never make it to the ground, exploding in a flash as 
> they are superheated by friction as they speed through Earth's upper 
> atmosphere..."
>
> Wasn't there just an asteroid not much larger than this that hit earth and 
> was recovered?
>
> Original Article On NASA's Website:
> http://neo.jpl.nasa.gov/news/news159.html
>
> After Recovery:
> http://www.nasa.gov/topics/solarsystem/tc3/
>
> Wikipedia:
> http://en.wikipedia.org/wiki/2008_TC3
>
> How big DOES an asteroid have to be to survive entry? It matters at what 
> velocity and angle it enters I know but... There are other factors to 
> consider is material or mineral composition, and of course density and 
> size.
>
> So how big was 2008 TC3?
>
> -- 
> Regards,
> Eric Wichman