Bristol news. [volume] (Bristol, Va. & Tenn.) 1867-189?, 1871-03-03

nsr Y0a: o. kpplstOa Co. 1871.
From the New York World.l
CONTINUED.
There II yet another and quite sin.
gular instance In the history of tine
solar system in which the detached
ring has failed TO become a single we'll
defined planetary mass. We allude to
the coterie of small planets the so
called planetOids or asterOids-which
revOlve beyond the orbit of Mars, about
halfway between the sun and the orbit
Of Jupiter. About hundred of these
little planets have already been dis
covered, and each year adds new names
ts the list. Four of them-Nesta,
Juno, Ceres. and Pallas-are of re-
spectacle dimensions, the largest, Pal
las, having diameter of 600 miles, or
more than One-fourth of the diameter
Of our moon. Most of them, however,
are very tiny. The smallest of those
already observed have a surface prob
ably not gTeatesr than that of the
State OF Rhode Island. and doubtless
many Of them are no larger than the
aerolites which the earth sometimes
seizes in its journeys through space
They occupy the position which should
otherwise belong to a single planet be-
tween Mars and Jupiter, and that they
have all originated from a single ring
Is tOlerably certain, since their orbits
are interlaced in such complicated
way that, if thGy were material rings
instead of ideal curves, it would be
p0esible 10 lift them all up by lifting
any one of them. Why shonld one of
the solar rings have failed to form d
single planet? And why should such
Hn arrest of development have occur
red just in this particular part of the
collar system?
According TO OILERS, the discOverer
OF Pallas and Vesta, there has been no
such arrest of development, these little
b",iies being merely the fragments of
an ancient well-developed planet which
has exploded. But this hypothesis,
though cOuntenanced by Mr.. Spencer,
Il not generally accepted 10y cOntempo-
rary astronomers, and il is contradict
ed by the movements of Nesta. The
fate of this remarkable ring may be
much more satisfactorily explained as
due to the I'erturbiug attraction exerted
upon it by Jupiter.
When We recollect that the distances
between the planetary orbits increase
almost ia g"Ometrica. ratio as we go
from the sun-so that, for instance,
Jupiter is nearly twice as far removed
rs the asteroids, Saturn nearly twice
a. far ~ Jupiter, and so On-and when
we estimate the immensely of the dir
tances which separate the outer plan
etc from each other, even i'm cOniunc-
tion; we shall see that up to the time
Of the detachment of the asteroid ring,
I'm st,I 4.
turbed in its formation by the attrac-
tiOn of its next outer meighbor and
predecessor. But as the planets began
To- be formed on a larger and larger
Ssale, and nearer and nearer together,
there began to Toe some danger of such
disturbance. Yet the enormous Jupi-
ipr-ring, never distant less than 4Og,-
0W 'En miles from Saturn, and being
from it, huge size unusually capable of
regulating its own motions i'm defiance
AZ external forces, ran little risk 0i
InrrtinSwith disaster in the course of
= its planetary development. II was
otherwise with the ancestral ring uf
the asteroids. These little MASSES, if
all piled together, would not make Il
piSiH't - large a. Mercury; and cons,'-
uu-ntly their ancestral ring, with "a
ANNhN -i'lti lilllNN
~ extensive as Mcrcury's, must have
I..-n Ivy far the most slender ring
which has ever been detached from the
sun. Yet this thi: est and weakest of
rings started on its independent career
at distance of only 2i0, 900. 900 miles
from Jupiter. the eIaut planet, whose
weight is more than twice that of all
the other planets put together. Und.r
.sta..i. Kt-nttll
possible that a planet could he formed.
The a~tcroid-ring must have been liza
HE 'o rupture, not only 10y resnn OF it,
"wn sl,ndcrness aud the instability of
it, equilibrium. but also from the strain
-Irrlcd upon il, now in one part aud
now in another, hy Jupiter's uttrac-
ti"n. The fragments of ring. torn
zSunder by such cause, would not
continue to occupy the same orbit;
they would be dragged from the COM
mon path in various directions aud To
various distances, according to the
Rver-changing position of the disturb
ing body. Henceforward, instead of
chasing directly an each Others heels
they would rush along in eccentric,
continually intersecting paths, and
there would thus Ice no opportunity for
consolidation, except in the ease of two
fragments meeting each other ut the
intersection of their orbits. As final
assault, We should have, not one good
sized planet, but a great nunIb, of
tiny planets, with intersecting orbits,
revolving in different planes and eX-
hihitlag great differences in eccentric
ity. All this H. true of the group of
asteroids. While the mean breadth of
the ideal zone formed their orbits is
about one hundred million miles, its
extreme breadth reaches two hundred
aud fiftN' million miles. The orbit of
Freia, the least elongated of all, is
much more elliptical than the orbits of
the major planets; while the orbit of
polyhymnia attains an almost come
tary eccentricity, the difference be-
tween its greatest and least distances
from the sun being nearly two hundred
million miles. Finally, while the
maiot planets, as we have observed, re-
Nulve in planes which are but slightly
inclined to the ecliptic-the orbit of
Mercury showing an inclination of
about seven degrees as the maximum
fnstance-the asteroids, on the other
hand, revolve i'm planes of quite vari-
Gus degrees of inclination. While the
arbit-planes of Massailia and Angeli-
ms nearly coincide with the ecliptic,
the orbit of Pallas rises above il at an
angle of thirty-four degrees. All these
circumstances point Ia the forcible
rupture of the original ring by the at
Traction of Jupiter, and thus we have
before Us the evidences that, at the
ilrst tilne.in the history of the solar
system at which such an untoward
event might be expected to occur, it
did occur.
IL is easy to show why such an event
5has not occurred subsequently. The
next ring-the one which gave rise to
Mars-was more than twice as large as
the genetic ring of the asteroids, and
was consequently, other things being
cQuai. better fitted 10 resist strain
from without. Moreover, being one
hundred and fifty million miles far
Their removed from Jupiter, The latter
planet could only exert upon four