St. Paul daily globe. [volume] (Saint Paul, Minn.) 1884-1896, 1884-11-15
WHAT COMETS ARE.

In recent article in Science" on the
distribution Of comets, there are some fea-
lures Of interest to ali those who have taken
any thought Of these celestial visitors OF
the mulutudes Of comets that have been re-
corded not all are Of that type which has so
often startled the unthinking inhabitants Of
the world. either filing them with apLrehen-
sion by a sudden and pretenuOus appearance
In the sky or rousing in them for the mo-
ment an interest in the wonders that lie
about US The majority now discovered fur
nish only theme for the astronomer and
subject to which he can apply the resources
Of his science for the Advancement Of that
science itself. So much Of his work is Of the
same nature that he is often looked upon as
entirely an impractical man, a de7otee OF an
art ironically described as too sublime for
the vulgar TO comprehend. But one should
not lose sight OF what has been done for the
practical objects OF navigation, surveying
aud even so ordinary IN affair as the regula-
ton Of our measurement Of time by the work
of astronomers in the fact, and though the
details OF such work may have been reekoned
OF slight account by others living at the time,
70 them We owe much Of the present perfec-
ton of these subjects. Every year nearly a
small number OF new comets are reported
merely TO the general public, which could
not be expected TO care for more, but TO the
astronomer each is a source of interest, aud
its welfare is looked TO as carefully as may
be, considering the great distances at which
these strangers hold themselves sud how anx-
iOus they would seem 10 be 10 take their de-
parture from the family Of planets, among
which they have become entangled.
Probably not less than FIVE thousand com
cts large enough TO have been seen with our
present appliances and quite likely 10 have
been picked no by the searchers Of our day
II the search had been kept up as vigorously,
have entered the solar system since the be-
ginning OF the Christian era. Could we
know as much Of all these az we do Of the
few that have been observed since the per
lection Of the methods now in use there
would be light no doubt on many obscure
points. Two hundred aud eighty-fYe orbits
can be found Of comets which have been
well enough observed to render 1t possible To
compute An orbit By these the astronomer
can trace the courses Of any OF the old COM
cts, not only during the period while they
were visible 10 the star gaZers Of The time
but before they had come into view at all and
after they had vanished from sight. Il is
thus quite possible TO determine the direc-
lion from which any or all Of them have come
before entering the planetary system, but
with this direction he must for the present.
stop; he can as yet go 10 further. While
there are still many mysteries in our solar
system yet TO " solved, Of the universe be-
yond its limits we know almost absolutely
nothing. We determine the directions OF
the stars, but the problem Of their distances
will never, in all probability be solved with
/ mn m fat ~ rrff aIlst
In the making and use Of instruments can
accomplish.
Meeting ship In mid-ocean, catching the
hrst view when 1t is on the distant horizon,
as it passes to vanish beneath the rim of
ocean astern one gets the course Of the stran-
ger and from its appearance might hazard a
guess as to its port Of departure and destina-
ton. These could be definitely settled we're
IL known 10 be holding to an invariable
course, uninGuenced by wind or current aud
not liable 10 collision unforeseen in advance
Nothing in the appearance Of a comet
/ gives us any clue as TO its origin, but we do
know that II is ooeying the same laws under
the sway Of which the earth swings on its
course aud as long as it remains within the
influence OF the sun, the ruler OF the planet
airy motions. the comet yields itself 10 the
same authority. At what distance the sun
first begins 70 exert this authority or what
forces have been in control of the comets
before the revolution by which they have
thrown of their old allegiance to accept the
hazards Of new can not be determined.
And there are hazardous epochs in the
short life Of many comets in the life ofwhich
the history can be written. Their paths nav
/ bring them close to one Of the big planets
whose attraction shall whirl them of their
previously adopted orbit into one that will
keep them revolving about the sun until
such approach shall twist them of TO recede
into outer space. This would correspond to
u certain extent TO a collision in space. 10
say nothing OF the chances of an actua
meeting face to face with one OF the planets
OF which chance our earth comes in for a
share one In a few billion or So Then II
they have not taken a course that will bring
them very close 70 the sun they are to be
subjected 10 a degree of heat beyond com
/ parison with our standards for molten metal,
even while the suns powers will likely de-
prive the comet Of material enough to form a
tail, which will be scattered far and wide to
form possibly meteoric display.
The direction only, then, from which the
comet comes is 10 be determined, and while
they may have come TO US from any of the
stars beyond the fact that there NAV be a
star in the same direction, more or less close
| perhaps TO several comets, nothing can be
definitely asserted. Through the realms of
space comets are scattered with n profusion
apparently inexhsusuble. If there are no
regions especially rich in supplies, and II
there are no causes BY which more would be
drawn from any special quarter we should
expect 10 lind the points representing the
origins or direction from which the comets
have come evenly distributed on all sides Of
US. There are groups of points OF origin,
whatever the cause OF these groupings may
be, too frequent to be accidental in an equal
distribution; and while the known points
form too small proportion Of all that must
have been established unknown 70 human
investigations. to draw any reliable coucIu-
sion, some effect seems 10 be trsceable TO
the motion of the solar system itself In
space Without going into this matter, IL is
enough 10 state that based on the small but
well-determined movements OF the stars as
seen from the neighborhood of the sun
which is but 4 star itself, the direction of the
motion OF the sun among the other stars is
considered known within no great uncer-
tainty.
The amount Of the motion Is not great
enough to affect the supply of comets by en-
hausting any region, but it does appear that
taking equal areas situated in a correspond
ing manner in the quarters respectively from
which and to which be sun is moving, car
rying with 1t the planets and all comets fully
under its sway, more come IN from the areas
behind. Moreover-and this consideration
is not Influenced TO the same extent by the
lack Of material, since fair portion NAV be
considered as giving in general indications
those coming in from the regions behind
/ on the average pass closer to the sun when