[meteorite-list] NP Article, 04-1887 Meteorite Explosion, Science of

From: MARK BOSTICK <thebigcollector_at_meteoritecentral.com>
Date: Thu Apr 22 10:18:28 2004
Message-ID: <OE58zxxfYXFrwiZ9rWj0001f7ff_at_hotmail.com>

Paper: The Herald And Torch Light
City: Hagerstown, Md
Date: Thursday, April 07, 1887

METEORITE EXPLOSION

     The great majority of people at some period of their lives have seen a
meteorite fall, or heard the sharp explosion from its passage through the
atmosphere. The query as to the nature of these explosions had led to a
unique discussion l' Astronime concerning them. In this it is shown quite
conclusively that the result of a meteorite passing through the air is
axactly analogous to that of a lightning flash. The electric current meets
with resistance from the air, which is therefore highly heated and expanded.
The colume of heated air is frquently several miles in length, and as the
duration of the flash is not the millionth of a second, the contraction of
this air column is practically instantaneous throughout its entire length,
and the thunder produced by the collision of particles bursts forth at once
from the whole column. Precisely the same results follow when any
projectile is driven through the atmosphere. The bullet whistles or "sings"
and the shell "screams." If a cannon-ball could be projected with a
velocity of 100,000 yards per second it would no longer whistle, but would
thunder. At the same time, owing to the resistance, it would be intensely
heated, vaporized, burst into a flame, and be immediately consumed. The
same results follow the projection of material into our atmosphere. The
most rapod cannon-shots rarely exceed 600 yards per second, while meteorites
commonly attain a velocity of 49,000 to 60,000 yards. At this velocity the
air just around the mass is heated to from 4,000 to 6,000 degrees C.
Expansion is correspondingly great, and the contraction of this long column
and collision of particles produce, as in lightning, a continuous roar of
thunder. This accounts for the "explosions," while also the brilliancy of
the meteor and its luminous train may be traced to its heated body and the
vapors thrown off and ignited during its progess.
Received on Wed 19 Feb 2003 01:29:41 PM PST