St. Johnsbury Caledonian. [volume] (St. Johnsbury, Vt.) 1867-1919, 1915-03-03
FLIGHT OF A COMET
ITS Wild Race Through Space and
the Speed 1t AttainS.
CRASHING INTO THE EARTH.

What the Result Would Be If One of
These Light but Massive Wanderers
of the Sky Were to Swing Into a
Head on Collision With Our Planet.
A large part of the fear that great
comets have always inspired is due to
an instructive dread of their tremen-
dous power For evil. They look like
besoms of destruction. and those who
know nothing about astronomy accept
them at their apparent face value.
And, in truth, if they could come
within hitting distance of the earth
they would do an enormous amount of
damage. and some of them might be
capable of putting the earth Temporal
rily out of commission as an inhabited
globe.
The terror that was aroused in many
quarters by Halley's comet in 1910 is
sure to recur on the appearance of any
new comet, so that it is worth while to
consider what an evilly disposed comet
could do to the earth if it got chance
There are two ways in which a comet
could cause damage to the earth-first,
by running straight into it with $1,000
times the velocity Of an express train
and, second, by injecting the atmos-
phere with the poisonous or sitting
gases contained in its tail.
Let US consider the first case of a
comet shock.
Two things have to be taken into
accOunt-namely, the velocity and the
=
sidered as a gigantic projectile shot
against the earth as a target.
Comets are very deceptive in regard
to weight or mass. They are enor-
mously large, but relatively very light.
The comet that appeared in 1861 first
grazed the sun and then swept the
earth with its tail.
Halley's comet also occupied vastly
more space than the earth, but a care
full estimate has shown that it prob
ably did not weigh more than 3O,OOO-
600 tons, which is much less than the
weight of the material excavated to
make the Panama canal.
1t might be thought, then, that the
earth is in no more danger from such
a comet than a battleship is from a
boys bean shooter. But now the veloc-
ity begins to come into play. The speed
of comet at the earth's distance from
the sun would be about twenty-six
miles per second.
A mass of 30,OOOOOO tons shooting
through space at a velocity of twenty
six miles per second would develop in
round numbers about twenty quintil-
lion foot pounds of energy. equivalent
to the development in one second of
thirty-six thousand million million
horsepower.
Where the comet struck everything
rock, soil, egetation-would be melt
ed, vitrified and even vapOrized in an
instant. for all this tremendous energy
would be turned into heat through the
sudden and complete arrest of the
swift motion of the comet. The 600
Quintillions of absolute units of en-
ergy' developed by the stopping of the
comet would furnish enough heat to
iquefy more than a million million
tons of solid iron!
The result would be very big and
a very deep hole in the earth. Thou
sands of square miles would be more
or less directly affected by the terrific
impact, for the shock would be greater
than that of the mightiest earthquake,
and perhaps buildings would tumble
into ruin and mountains would shake
off their fringes of rock in all parts Of
the globe, while the sea would hurl
itself in whelming tidal waves upon
every coast and drown all the low Iy-
ing islands.
The atmospheric disturbances would
also be enormous. The sudden devel-
opment of great heat at the point of
collision would unbalance the air cur
rents and destructive and capricious
winds would blow to and fro over the
earth.
We have only a little space left to
consider the effects of a collision be-
tween the earth and the tail Of a
comet. This is something that has
actually occurred two or three times |
within century. As already said, the
comet of 1861 enveloped the earth |
with the spreading end of it's tail for /
a few hours, and in 1910 HaIley's |
comet brushed it's tail over the earth, /
but apparently the electric repulsion
developed prevented the gases of the
tail from entering the atmosphere. 1t
is possible that in every case this
would occur, so that electricity may be /
our effective guardian against dele 1
ferrous substances that might other
wise be introduced into the atmos-
phere from the switching tails of close |
passing comets.-Garret p. Serviss in
Spokane Spokesman-Review