[meteorite-list] Meteoroid Temperature-Pretty Graph

From: MexicoDoug_at_aol.com <MexicoDoug_at_meteoritecentral.com>
Date: Mon Jan 10 12:33:50 2005
Message-ID: <83.1ead7f25.2f1412dc_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/148343.html
http://six.pairlist.net/pipermail/meteorite-list/2005-January/148344.html
Received on Mon 10 Jan 2005 12:18:20 PM PST