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" <[email protected]>
To: <[email protected]>
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
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