The Indiana State sentinel. [volume] (Indianapolis) 1868-1895, 1878-03-13
AN ASTRONOMICAL PUZZLE.
A Moon Which Rises in the West
A New Theory to Account for the TX
traordi nary speed of the Inner
Moon Of Mars.
New York Tribune.l


Hall, the discoverer of the moons of Mars,
has for some time been interested in theory
suggested by Professor NJ. II. Doollttle, OF
the coast survey, explanatory of the peculiar
ity In the revolution of the inner satellite,
which makes its journey about the planet In
shorter space of time than that occupied
by the planet in revolving upon its axes As
is is well understood this fact presents an
anomaly in astronomical science. Last
Saturday night Professor Doolittle explained
the full details of his theory before the
philosophical society of this city. His paper
attracted marked attention from the men,
bers of the society.
The observed periodic time of the inner
moon of Mars around its primary is frac-
ton over seven hours. The revolution of
Mars itself on its own axis is accomplished
in about twenty-four hours. The discrepan-
cy between the periods of the planet and its
satellite in favor of the quicker revolution
of the latter can not, in accordance with the
terms of the nebular hypothesis, be account
ed for without conceivIDg the existence of
some cause which has operated to shorten
the radius of the satellites orbit. In ex-
planning his theory of the discrepancy re-
ferred TO, Professor Doolittle mentioned the
fact that the radli of planets are shortened
by any resistance which they may meet.
From this arises the paradox, well known to
astronomers, that the velocity of planets is
accelerated by resistance.
erous ether possesses the power of resistance
to the planetary system. This was predicted
on the observed acceleratiOn of Enckes
comet in some of its revolutions. Mr.. Doc
little dismissed such conclusions to the
luminiferous ether as referring to substance
so different from ordinary matter that it is
scarcely proper to say what is credible or
incredible in regard to it. He called atten-
ton, however. to the existence of matter in
the inter planetary spaces which is not
purely conjectural. This matter Is that of
the shooting stars or aerolites. This known
"IsTER. STELLAR"
matter is assumed by his theory as being
that which may possibly have operated as a
sufficient cause of resistance to planetary
bodies TO shorten their radii and accelerate
their velocity. This being granted, the
unique phenomena observed in the rapid
revolution of the inner moon of Mars would
be explained. 1t has been observed that
larger number of aerolites strike the earth
in front than IN the rear. While other
causes of planetary acceleration through
resistance have already been conjectured,
this only known cause has been largely over
looked
- Professor Doolittle showed that the action
of the aerolites would tend to increase the
comparative rspidity of a satellite in three
different ways: First, by striking the satel
lite and increasing its rapidity of revolution
in the manner already explained by making
it revolve in smaller orbit; secondly, by
striking the primary, thus increasing its
mass and its attraction of the satellite;
thirdly, by increasing the mass of the pri
mary and thereby consuming its original
velocity through the taking up of this
increased addition to IT'S mass. However
slight may be the annual average effect thus
produced, any asslgnable diminution of
radius and increase of velocity is attainabIe
IN a sufficient number OF years, and it may
49,
tive scientific knowledge that if these causes
now in operation continue TO operate as
efficiently as, in the past, the inner moon of
Mars has simply reached a condition which
all planets ana satellites are destined ulti-
mately to reach; and the time will come
when our moon will rise in the west and set
in the east The inner moon of Mars, by
reason of going faster than the planet pre-
sents this phenomenon now to an inhabi tant
o. Mars.
There is reason, however, to believe, Pro-
lessor Doolittle asserts, that these causes
operating to accelerate the velocity of
planets will not continue to operate with
undiminished efficiency. 1t is known that
many aerolites belong permanently TO the
solar system, and 1t Is not unlikely that they
all do. Ii so. their quantity must be finite
and exnaustible and probably nearly ex-
hausted.
at the conclusion of the paper, which was
theory was discussed by members of the
society in a manner which showed that it
had made an impression, especially upon
those familiar with
ASTRONOMICAL SCIENCE
and speculation. Professor Hall, who was
present, declared that not only is Laplace's
nebular hypothesis insufficient to account
for the anomalous position and velocity of
the minor moon of Mars, but that the sup
Elementary hypothesis. which was adopted
TO explain the irregular motion of Encke's
comet also tails to afford satisfactory ex-
PLANTATION of that phenomenon. He said
that from the latest computations of that
comet its velocity appears to be accelerated
in some OF its periodic revolutions, and not
in others, which is explained upon Mr..
Doolittle's theory, as the comet would prob
ably encounter aerolites in some of
its revolutions and fail to en-
counter them in others while
all the causes hitherto conjectured would be
regular in their action. The discussion was
the regular adjournment of the society by
Professor Hall and others. Among those
present at this meeting of the philosophical
society were Professor Simon Newcomb, of
the naval observatory; Professor Hilgard, of
the coast survey; Commander Hull, hydro
grapher of the coast survey; Mr.. Dali, of the
coast survey and Smithsonian institution
President yelling, of Columbia university;
DIR. Anrisel, chemist, latelyin Japan; Pro-
lessor Gilbert and Captain Dutton, of the
Powell exploration, and Drs. Woodward and
Billings, of the medical museum. Several