(meteorobs) Definition of a meteor (was Re: Fifth grade sciencebook)

[MexicoDoug at aol.com]

I promise this is my last post on this:)

John, while the holy grail  of twisted definition questions is what the 
Alabama lady was hit by (meteor,  meteorite, meteoroid, ouch), I just wanted to 
point out that NASA and artificial  satellite manufacturers frequently speak 
about micrometeorites when  they are in space.  There are plenty of purists that 
call them  micrometeoroids, but even the astronauts have frequently referred to 
 micrometeorite threats.

Here's what NASA is telling our kids, just to  leave everyone scratching 
their heads (scroll down to micrometeorites if you go  to their glossary, the 
def'n is reproduced here below):  http://lsda.jsc.nasa.gov/kids/L&W/glossary.htm
"Micrometeorites-Small  particles with the size of a molecule which travel 
through our solar system or  orbit the earth. Travelling with high speeds, such 
micrometeorites can cause  damage on the surface of all exposed material 
during impact."

The fact  that they are moving at high speed, not necessarily in Earth orbit, 
not in the  atmosphere, and embarrassingly the size of a molecule, doesn't 
seem to matter on  that particular page for kids.  These micrometeoroids and 
microsatellites  can be called "micrometeorites", even if they skip off the shell 
of the human  apparatus and head for Jupiter.  Again the point of view: it 
can impact the  hardware and cause damage, apparently anything that can cause a 
crater is a  meteorite, whether a geologist finds it with a steel or silver 
pick or  not....

Though for teachers a NASA glossary is different:
_http://quest.nasa.gov/space/teachers/liftoff/eva.html_ 
(http://quest.nasa.gov/space/teachers/liftoff/eva.html) 
Micrometeoroids  - Tiny bits of naturally occurring rock and metal traveling 
through space at  high velocities. (Newton smiles)

If you want to really listen to the  scientists, you can argue that a 
meteorite isn't officially a meteorite until a  Meteoritical Society scientist 
confirms it so, or until the Society votes to  accept it with a provisional or 
permanent name.  Everyone knows there are  about 20,000 meteorites give or take 
Antarctica and hot desert confusions  :)  So it is not good to get lost in the 
recent technicalities in this case  vs. look at the etomological history of the 
word - I would  suggest.

Recently I had the opportunity to speak with a nice person who  watched a 
daytime rock from space get delivered from creation to the ground  twenty-five 
feet from him.  He never once had a need to put a name on it -  it was a "black 
stone", I may add he saw coming out of the sky, which he  described as "going 
like hell", accompanied with a powerful language and really  animated 
fist/arm/elbow jerk and accompanying teethgritting facial  expression.  He heard the 
rumbling minutes before, and saw the smoke trail  which drew his eye to the 
actual stone in fall.  He promptly picked it up  out of its depression it created 
and found it warm, but then it became  cold.  He said someone else came by 
and told him it was a "meteorite" and  laughed at the sound of the word 
"meteorite" for that "black stone".  He  wasn't a geologist or a rocket scientist:)

Saludos, Doug
 
PS, the Newton who invented the word "meteoroid" did so in the mid  1860''s.  
I just looked it up - it wasn't Isaac.  It was H.A. Newton  of Yale.  So 
meteoroid is before atmosphere by definition no matter what  anyone else says (It 
is hard to argue with a clear definition), meteor is an  archaic term, and 
meteorite is what's a geologist might luckily find while going  on a field trip.  
If you want to restrict meteor to the light and not the  object istself, 
sounds good, then it is a meteorite during entry.  If  you want to call it a 
meteoroid, you are modifying the historical definition of  the word, but that's 
fine too.  If you want to call it meteor, you are true  to the original meaning 
of the word.  Just don't call it a fiery meteor if  it isn't glowing and that's 
fine too.  I'll be calling it a rock from  space, aerolite, or falling iron 
from now on so I keep my  friends...



En un mensaje con fecha 04/28/2005 2:14:09 PM Mexico  Daylight Time, 
jkuehn8 at comcast.net escribe:
Human intervention, I.e.  modification or transportation, would preclude 
it from the aforementioned  'NATURAL' category.
A space turd is still a space turd  if brought back  intact.  but, let it 
fall naturally, and only then it could be  considered a meteor. 

If in daylight you were lucky enough to see a  natural falling rock 
during the non ablative /dark period, I would still  contend that is 
still is a meteor

Unless the definition of meteor  expressly REQUIRES that the object be 
self exo- luminescent. Then I would  have to ask at what wavelength and 
what level above ambient ..... The  nits... and the nitwits, their 
everywhere.

I would imply that, it is  the MOTION that is inferred by the term meteor 
and that it has an additional  characteristic in that it MAY emit light 
during its meteoric fall to  earth.

I would leave it to the experts/nit pickers to specify EXACTLY  what 
point the  non captured, free flying, meteoroid's  orbit   becomes 
entangled by the geo- gravitational field and  commences it's Meteoric 
fall to earth, with all of the possible dark and  light segments of that 
journey. Until it subsequently comes in contact with  the ground, 
stopping the motion and changing it's status to the earth borne  form 
named METEORITE.

If standing or lying on the earth and are  struck by a non luminescent 
natural falling object, would you say you have  been struck by a meteor, 
meteorite, or meteoroid  or just  ouch?

IMHO

But then again.... maybe not.

GeoZay at aol.com  wrote:

> 
>  
>
>>>1. Any  natural  extraterrestrial object that has touched  the earth is  
>>>       
>>>
>considered a  METEORITE<<
>
>
>So, if one of the moon rocks brought  back to earth by the apollo  
astronauts 
>is dropped...you'd call it  a meteorite? :O)
> 
>
>  
>
>>>2. Any  natural object in free space that is smaller than an  asteroid is  
>>>       
>>>
>considered a METEOROID<<
> 
>Pretty  much so.
>
>  
>
>>>The contention seems to  be during the fall  to earth.
>>>       
>>>
>When during this atmospheric, ablative period, and  post  luminescent 
>/dark period  is it proper to use the  generic terminology  and call it a 
>METEOR?<<
>  
>During this dark period, there will be no ablation...it's too slow  for  
that. 
>and to say that a meteor is post luminescent doesn't  make any sense  
either. 
>Since a meteor is the light phenomenon  itself...not the object. During  the 
>objects dark phase, there's no  longer a meteor present. 
>  
>GeoZay
>
>
>
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