Evening journal., 1921-06-13
DON'T WORRY,
EARTH ISSAFE
Comet Will Miss United
States on June 27 by II
Million Miles
HOW TAIL STANDS
WEAR AND TEAR

WASHINGTON, d. c., June "a
A modest little local brief in the jour
nal of this universe which a ply
sicist believes to have some limit,
even though one astronmer now con-
ceives it to be a thousand times
larger than we thought it, might
read like this:
"On June % the tiny planet,
Earth, is expecting to see sparks
(meteoric showers) from the swish
Of the 1000. .OOO-mile tail Of the
comet. Pons-Winnecke. which will
just miss hitting Earth by only ~
million miles"
Though we are not certain OF
the exact nature OF these hairy
stars, astronomers believe comets are
made up Of small particles. very far
from each other, surrounded by
masses Of gas" explains a bulletin
from the Washington headquarters
Of the National Graphic Society.
"The main body OF a comet var
les from a few hundred to a few
thousand miles in diameter, and its
tail, which makes it as spectacular
among heavenly bodies as the tail
of the peacock makes him in the
bird world. measures from a few mill
lion TO more than a hundred million
miles in length.
''The tails Of comets have some
peculiar characteristics. They al
ways turn away from the sun, and
they increase and decrease with as
tonishing rapidity. the sun evidently
causing them to lengthen enormous
ly. Though its volume is very great,
the actual mass Of a comet is very
small Scientists tell us that the
average density Of a comet is but a
fraction Of that Of the air near the
earth's surface and that the density
OF the extSemity of the tail is. OF
course, very much less.
This is evident from the fact
that these bodies. which are so much
larger in volume than the planets.
are DETECTED from their orbits by the
planets, which are not even dis
turbed enough by their appearance
for any observations TO be taken OF
Il. Even when comet passed
through Jupiter's satellite system in
1856 not a moon veered from its
course, but the comet totally chang
ed its orbit as a result Of the mag
netic force exerted. That the
substance OF comets and their tails
is much rarehed is further apparent
because even the faintest Of the Wis
BILE stars can be seen through them.
Work associated with the be-
havior and the nature Of comets and
their orbits is yet in its infancy. and
the knowledge that the spectroscope
reveals regarding their composition
is confusing. II seems to say thai
they are made Of hydrocarbon vapoi
. which shines by its own light bu
part OF their light must be reflected
sunlight as the brilliancy Of a come
increases as it approaches the SUI
and diminishes as It passes away.
"The idea that comets are wan
derers in space has long ago beer
given up. Now we know that thel
belong TO our solar system, bu
their orbits are such parabolas oi
ellipses that they sometimes require
hundreds of thousands Of years {,
complete a revolution. Occasion.
ally the fascinating Jupiter will lur'
. one Of the shooting stars from III
straight and narrow path. Like th'
, foolish moth It will revolve arounS
the greater light and apparently FOL
brief while become a part Of oui
system. only to pursue its own wa.
, after discovering the vanity Of IL
, affection. When the comet chances
~ .F
experience a meteoric shower. Tht
, is what we are told is to happen Z
us as the result of the visit Of Pons
Z Winnecke.
Sometimes Jupiter reduces then
, entirely to subjection and they sta,
on with that planet as part Of IL
numerous and expansive family
They then circulate in elliptica
orbits around their conqueror an
, gradually dissipate their substanc
along their tails until they becom
entirely invisible.
"The tail of a comet in all its gor
, geousness is not a mere appendag'
, II il were, it would not long stan
i the wear and tear that hurtlin
I through space would give such
S thin mascot matter, nor could II b
70 tipped from one side to the other a
is the case when the body passes &
n the neighborhood of the sun. ]
. must be made largely OF dissipatin
4 vapor, never the same from secon
e to second, volatilizing or evaporat
y ing from the heat OF the sun, {
G shift like the smoke in a chime
h with the outside influences whic
control IL
l"All Of us remember HALEY
comet because 1t appeared in all Il
k noted brilliancy in 1910 on its az
n, year tour of the skies in harmon