(meteorobs) Meteoroid Temperature-Pretty Graph

[MexicoDoug at aol.com]

Hola Lists (and especially Lars who I hope is feeling somewhat better in  the 
wake of the storm in the State of  Denmark),

http://www.diogenite.com
then click on "Meteoroid" on the  left.

Last night I put together a simple graph of Meteoroid  temperatures for 
Ordinary Chondrites, Carbonaceous Cs, and Iron-Nickel as  well.  Just pick your 
distance from the Sun and read the outer space  temperature of your meteoroid 
anywhere up to around 0.79 light years (50,000 AU)  from the Sun...though 
materials tend to behave differently as they approach  absolute zero and molecular 
rotational and vibrational motion -which drives  temperature- approaches a 
standstill.  Ceres is at 2.8 AU on average, by  the way.  Vesta a little closer 
(average 2.4 AU).  
 
The graph on the webpage covers everything from Mercury to Jupiter  
distances.  

And if that's not enough, you can download the workbook  (MS Excel) and look 
at similar bright graphs fof up to Pluto and then as a  special bonus another 
one with a log distance axis to reach the Oort  Cloud.  One can see it is 
about two degrees above absolute zero out there  if you are a surprising Iron way 
out there, but only one degree abouve absolute  zero (0 = -273 C)if you are 
just a good ol' ordinary chondrite or carbonaceously  cruising.  

It is interesting to note that if you are an Iron  orbiting Earth, you are 
not cold.  You are near the boiling temperature of  water!  And ordinary 
chondrites are a little below freezing!  It makes  a big difference what group you 
are!!!  Iron meteorites are hot to start  with upon entry !  Of course all bets 
are off of the meteoroid is being  eclipsed by Earth's shadow.  Then it is 
much colder than frigid if it  has any time to equilibrate at 
all.......brrrrrr!!!!  So a night time  meteor probably starts out frigid with a capital F, 
though larger meteorite  producing bolides at thousands of kilometers per hour 
probably aren't too much  affected before friction takes over.  The assumption in 
the model fails  that radiative equilibrium is reached during an eclipse.  But 
this is an  important consideration I think - a night time fall and a day 
time fall  potentially can have very different inicial temperatures:)

Saludos,  Doug
Assumptions on Meteorite List January 7:
_http://six.pairlist.net/pipermail/meteorite-list/2005-January/148342.html_ 
(http://six.pairlist.net/pipermail/meteorite-list/2005-January/148342.html) 
_http://six.pairlist.net/pipermail/meteorite-list/2005-January/148343.html_ 
(http://six.pairlist.net/pipermail/meteorite-list/2005-January/148343.html) 
_http://six.pairlist.net/pipermail/meteorite-list/2005-January/148344.html_ 
(http://six.pairlist.net/pipermail/meteorite-list/2005-January/148344.html)