New-York tribune., 1921-06-12
y OR the last few months little
comet with q big name--the

tronomers than usually falls to the
lot of such an inconspicuous and COM
paratively unimportant member of the
suns large family.
There has been suspicion for some
time that this small body was so tim
ing its latest periodic visit to the sun
that it might come unccmfortably near
for itself-to our own planet about
June 26.
The astronomers undertook some
calculations to determine the position
found that the comet itself would slip
past the earth this month with a safe
margin of twelve or more million miles.
But it is quite possible that there will
be fine display of meteoric fireworks
about the 25th or 26th of this month,
when the earth will come so close to
the path of this comet that it may pene-
trate some of the swarms of meteors
that are following in the trail of the
comet.
Comets are bodies OF great bulk and
small total mass. They are made up
Of masses of loosely gathered meteoric
stones intermingled with gaseous mat
ter. Their heads are usually thousands
of miles in diameter and their tails,
which are composed of finely divided
matter driven off from their heads by
light pressure and electrical repulsion
when they are nearest to the sun, may
extend to distances of millions of miles
in a direction away from the sun.
In addition to having such an ap-
pendage, comet is usually attended
or followed by more or less extensive
swsrms of meteors, which are simply
detached portions Of the head or nu-
cleus. These meteoric swarms are apt
to be encountered at any point in the
comets path. They are not necessarily
confined to it's immediate vicinity, but
NAV distribute themselves all along its
path, Frequent returns to the sun and
close approaches to disturbing bodies
such as the planets and, in particular,
Jupiter cause the gradual breaking up
of the nucleus of the comet into many
dets ched portions and the distribution
of these fragments along the comets
path in the form of swarms of meteors.
d.
Nav Cause ALI the Fireworks
So, even though the PonsWinnecke
comet passes the earth at comfort
able margin of 100000 miles, it is
the close approach of the earth to its
path about June 26 and its chance pene~
tration of heteoric swarms that are
trailing behind the comet that may re-
suit in fine display of meteors.
The -Winnecke comet is mem
ber of Jupiter's family of comets. These
comets all have the most distant points
In their orbits-their aphelia-in the
neighborhood of Jupiter's orbit, owing
to the force of his attraction for these
small bodies. 1t is by no means
newly discovered member of the solar
system. The astronomer Pons first OBJ
served it in the year 1919. Its orbit
was then calculated, and it was found
to be short period comet, returning
to the sun about every five and~a half
years. For some reason, it was not
observed on subsequent returns until
Winnecke rediscovered it in 1858.
Hence it's name of the Pons-Winnecke
comet. Since that date it has been re-
observed at number of returns to
the sun, and has always been an in
conspicuous object, usually invisible to
the naked eye at nearest approach to
the sun, or perihelion passage.
This comet has had number of dis
astrously close approaches to the huge
planet Jupiter, which have greatly dis
turbed it's motion, changed the form of
it's orbit and disintegrated more or less
the nucleus of the comet.
Its chief interest for us lies in the
fact that these changes in the form of
its orbit have brought it's point of
closest approach to the sun-or peri
helion-closer and closer to the earth
on each return. It's period has been
heightened to nearly six years and it's
perihelion at this return lies only
about two million miles beyond the
earth's orbit. 1t is this increase in its
perihelion distance that makes pos
sible the earth's encounter with the
streams of meteors that follow in its
wake.
At its last return in 1915 the comet {
passed its perihelion in September.
Nine months later, May-June. 1916,
when the comet itself was at an enor-
NOUS distance from the earth and the
earth was within a few million miles
of the comets path, it encountered
swarm of meteors following far in
the wake of the comet. 1t is believed
that there are a number of distinct
swarms of meteors following this
comet even at very great distances be-
hind the comet itself, and also that
these swarms spread out to a consid-
erable extent on either side of the
path. 1t is these facts that point t.
strong possibility Of fine display
of meteors about June 26, for at tha,
time the earth. will be very much
nearer to the comets path than it was
at the last return.