Mineral Point tribune. (Mineral Point, Wis.) 1869-1938, 1879-02-19

Moons Falling into Planets, and Planets
into SUES.

ne IilISth E1aAltt N.ttNAA IL Is S6UtIalsN
supposed by astronomers to present a
picture of planetary existence III its
earlier stages. Although the planet al
ready has eight moons, the matter
forming the rings constantly tends to
shane itself into new satellites. The at
tractive force of the great central mass
as constantly overcomes this tendency,
and is believed to be drawing the rings
closer and closer. The Russian astron-
omer Otto Struve has predicted that in
less than two centuries the inner ring
will reach the planet and beunited with
it. While his views are not accepted by
all observers, the fact is conceded that
great changes are going on in the girdle
Of saturn, and there are strong reasons
to conclude that the manner of which
it is made up once moved in a larger
circle than it now occupies.
This conclusion is the basis of a paper
contributed by Prof. Daniel Vaughan
to the last number of the Popular Science
Monthly, in which some interesting if
not startling proposition are advanced.
Various opinions have been enter
tanned as to the construction of the
Saturnian rings, While they can hard
ly be wholly gaseous or liquid, there is
difficulty in regarding them is COM
posed OF solid matter, since bat few
solids are known which would endure
the violent commissions that frequently
disturb the great circles. 1t Is suggest
ed in this paper that the principal con-
stituent may be water at tempera-
III, frnnyi,,n IL, ~
case, the constant tendency to freeze
would slightly overcome the destruc-
tive forces and would account for such
changes OF form rs are revealed by the
telescope. OF course these changes
could not go on without heat from
some source, but it is assume that a
sufficient quantity IS evolved mechanl-
cally by the commotions themselves.
There seems TO be no doubt, however,
that the rings of Saturn are such stuff
as moons are made Of, but the question
is whether this material is to form
moons in the future or has already per-
| formed its function III this respect by
| forming moons in the past? Prof.
! Vaughan adopts a view which indicates
his belief that the planet has already
entered upon the later stages of It's life.
| He thinks the two rings were formerly
! two satellites moving about Saturn III n
wider zone. A dismemberment and q
conversion into a ring, he says, must
be the general fate of every planetary
body land moon is planetary body
which, by slow contraction of the
| path in which it moves, reyolyes at least
too close to its primary-that is. too
close to the larger planet around which
ii travels.
But what causes the orbit Of satel-
lite TO contract so as to bring it thus
dangerously near to the central mass it
revolves about? Evidently some OBJ
stacle to motion would be sufficient
something which retarded velocity,
very slightly, it might be, but still
somewhat. An influence OF this nature
must be exerted by any substance, how
ever tenuous or ptherial, which per-
vades all space, or that part of space,
at all events, to which the stars and
planets, belong. Like many other men
Of science, Prof. Vaughan assumes the
| existence of rare medium Of this sort
disseminated throughout all the known
| stellar regions; and to its action OF re-
tardation he attributes the transtorma-
ton of the lost moons Of Saturn into
tie mighty rings which now encircle
! that planet. Evidence that resisting
medium really exists has been supplied
by the recent discovery of the satel-
| lites of Mars; and our author declares
that not many million years can elapse
! before the inner moon, Phobos, Will
have its path so shortened as to be
brought within the atmosphere of the
planet. Then, he says, It's career as a
small secondary world will close with a
meteoric exhibition.
And why may not our own moon
come to an end in the same way? In
deed, is not such a result extremely
probable? The same cause must be
effective to check its rate Of motion,
and the chief difference between the
two cases would be in point of time.
The few millions OF years requisite for
the absorption OF Phobos would have
to be multiplied by several hundreds tc
make up the period which will elapst
before the moon is similarly destroyed
The occasion will be a grand one, how
ever, for we are told that it will be sig
nalized by far greater display OF
meteoric effulgence. Dliapidation WI
begin before the moon actually touches
the earth; innumerable fragments vii
be hurled off az meteors i'll our atmo
sphere and the brilhancy Of the scene
will rival the light of the sun. Prof
Vaughan thinks that only portion o
the moon will be appropriated by the
earth at the first near approach. Tn'
part that is LETT will haul off, as It were
into space, to give rise to a similar
magnificent outburst some millions o
centuries later when it again comes toe