[meteorite-list] hot meteorites

From: Donald Blakeslee <blakesle_at_meteoritecentral.com>
Date: Thu Apr 22 09:41:09 2004
Message-ID: <3.0.2.32.20010212150718.006e64b4_at_twsuvm.uc.twsu.edu>

I wonder if a little mose discussion might be warranted. High speed planes
land hot, but meteorites are supposed to land cold after having been heated
to the point where the surface melts. The explanation that meteors ablate
and jets do not has been offered, but this doesn't account for the
difference fully. =20

The meteor is hot enough to ionize the air until it reaches its point of
retardation. As it continues to slow down, the air will cool it, but so
long as it is traveling at the speed of a jet, air cannot cool it to a
point cooler than the jet planes. Only when the meteorite is slowed to a
much lesser speed can air cool it.

Clearly the fact that the interior of the meteorite is cold is an important
factor in re-cooling the surface. I tend to agree with the idea that a
very freshly fallen meteorite can feel hot to a human hand but that left
alone for a while, it will cool rapidly, expressing the interior=
 temperature.

Farrington's 1915 catalog of meteorites has lots of details of falls, and
in the large majority of cases where temperature is reported, they were
hot. This is true even if you throw out the clearly loony reports of
incandescent stones. Here is a list I compiled.=20

Hot Meteorites
Name Date Weight Description
Alfianello 1883 228 alleged to have singed the grass slightly (Heide
1964:23)
Farmington 1890 90 hot when dug up (Farrington 1915:185)
Ferguson 1889 77.5 too hot to hold
Cabin Creek 1886 48.6 hot (Farrington 1915:89)
New Concord 1860 46.8 as though it had lain on the ground exposed to
the sun's rays (Farrington 1915:330)
Warrenton 1877 45.5 snow was melted and frozen ground=20
                                thawed, but pieces, though warm, were=20
                                easily handled (Farrington 1915:476).
Braunau 1847 39 too hot to touch for 6 hours=20
                                (Bagnall 1991: 16)
Allegan 1899 31.8 too hot to handle (Farrington 1915:30)
Juromeha 1968 25.3 incandescent when discovered; still warm next=
 morning
Bath 1892 21.2 had to use gloves (Farrington 1915:48)
Nanjemoy 1825 7.44 sensibly warm (Farrington 1915:324)
Searsmont 1871 5.4 quite hot (Farrington 1915:406)
Mazapil 1885 3.95 still luminescent for a while after impact, hot when
finally picked up, could barely be handled (Farrington 1915:299)
Luc=E9 1768 3.5 too hot to handle (Burke 1986:27-28)
Tomatlan 1879 0.9 still at a burning heat
Cross Roads 1892 0.17 grass near the spot was dead and looked as if it
had been killed by fire (Farrington 1915:150)
Queen's Mercy 1925 ?? smoking hot; burned a woman's hand (Burke=
                                 1986:226)=20
Cold Meteorites
Dhurmsala 1860 150 had frost on its surface when recovered
                                (Burke 1986:100)
Forest City 1890 36.4 fell on dry grass but did not char it=20
                                (Farrington 1915:198)
Drake Creek 1827 5.2 cold when freshly fallen=20
                                (Farrington 1915:168)
Harrison Co. 1859 0.7 not warm
Lumpkin 1869 0.4 neither hot nor cold
                =09
                =09
        =09
                =09
                 =09






Don Blakeslee
Department of Anthropology
Wichita State University
Wichita, KS 67230-0052
Received on Mon 12 Feb 2001 04:07:18 PM PST