The Bossier banner. [volume] (Bellevue, Bossier Parish, La.) 1859-1952, 1882-04-13
That Threatening Comet.

by comet falling into the sun, some
fifteen years hence, was referred to edi-
torially by the Tribune last Sunday. 1t
was then stated that the matter would
be referred to the Tribune astronomer.
The promise was made in a ocular way;
but so many readers have since expressed
desire to shear from him. on the SUBJ
ject that he has undertaken response.
There is certainly some reason to think,
or fear, that the comet referred to will
really fall into the sun. The mere fact
that the comets of 1868, 1843 and 1880
were all travelling in nearly the same
path does not prove their identity. But
the fact that they Cor it) nearly grazed
the surface of the sun at the nearest APP
proach does furnish good reason to think
that the motion in the curve was thereby
retarded; and the necessary conse-
quence of such retardation must be final
destruction of the orbit. The comet of
1843 passed within about so, 900 miles of
what appears to us to be the sans nor
NAL surface. The observation of the solar
eclipse of 1869 satisfied the writer that
the sun has an atmosphere which extends
at least 800, 900 miles above the apparent
surface. That Isl it extends out ten times
as far as the least distance of the comet.
The solar atmosphere must be exceeding
ly rare in that vicinity, but SO is the
earth's atmosphere at the height of 100
miles; and yet we know that the latter
retards the flight OF meteors SO much as
! to. warm them up to the luminous point
the motion being converted into heat.
Itiseasily shown that the passage through
resisting medium destroys much more
of the tangential motion than it does of
that which results from the action of the
centripetal force. Hence the orbit bends
inward more rapidly than before. This
means that the comet returns sooner to
the aphelion point, shortening the major
axis of the orbit and the period of revolu-
ton. If the comet pass through the re-
sisting medium at each perihelion return,
the orbit is soon broken up by the fall of
The comet into the sun.
1t is easy to calculate, approximately,
the quantity of heat developed by such q
catastrophe. Ii we take the suns radius
as the unit of measure, then the square
of the velocity on reaching his surface,
plus unity divided by the major axis of
the orbit, is constant quantity-the
!. same for every member of the solar sys-
tenn, except small variation due to the
quantity of matter in the falling mass.
With this we may calculate that para
bolic orbit would give greatest velocity
OF 1921 miles per second; and if the axis
of the orbit were shortened to equal that
of the earth orbit the greatest velocity
would be about 1872 miles. If, therefore,
the orbit Of the comet should be short.
nod dnfxr hxy f,x,N
helion passages before the final collapse
we should still have a maximum velocity
of about $50 miles. This would be con-
verted into heat. Dividing this velocity
by 223 feet, and squaring the result, we
obtain, in round numbers, 10000, 900
degrees OF the Fahrenheit scale as the
rise OF temperature OF the falling mass.
A large part of this would be distributed
by conduction among the material COM
posing the sun.
8 The next important point is to know
the quantity of matter in the comet; and
that we do not know. But we have sew
eral indirect reasons for believing that
at no time has, it been more than about
zone part in 5000. of the earth's mass.
And it is probably now much less than
80 On oiisso oty oAah 4udhatJ. 1He
5 passage through the suns atmosphere
!. esneafs on the gaseous matter OF the
comet ana It's attendant tram OF meteors,
both OF which are LETT behind by the more
*sold nucleus, as the latter PUSHES away
IN IT'S diminished orbit. Hence, though
!, the shortening OF the period does not de-
tract very much from the perthelic We
iocity, It does waterway lessen the guam
tity OF matter that IS left to be heated up
i by the last grand rush down into the
bowels OF the sun.
81 s. Now, II we allow the very greatest
possinle value Tor the mass OF the comet
JUST before u loses Its Individuality. we
shail ma the heat generated by the inn
pact 70 De just about equal to that thrown
on py the sun during one week. Allow
ing What seems 60 the writer to be the
ma maax q probable value, the resulting
neat would De equal to the present solar
expenditure during not more than two
days, and scarcely less than one. The
result IN the hrst, and worst, case would
! De an outpurst OF solarenergy that would