Evening star. [volume] (Washington, D.C.) 1854-1972, 1896-11-02
MARS INHABITED?
Prof O. A. Young Of Princeton Considers the
Question.
Our Planet Neighbor IL q Pretty Cold
Place and His Atmosphere In
by No Means Dense.

In a recent article in the New York Her
aid. Prof c. A. Young, the eminent astron-
omer of Princeton University, writes en-
tertainingly on the question Of the habit
ability of the planets. Prof. Young says
that as to the general question whether the
stars and planets are the abodes of life, we
can. of course. say positively on the one
hand that they may be. Plainly the ON
nipotent Deity can if He sees fit organize
forms of life suited to any possible condi-
lions, creatures that might flourish In the
solar fire. or in nebular fog. On the other
hand there is not the slightest valid evil
dence that such creatures exist. Consider
ing the vast emptinesses" between the
stars, and the nfeless ages of the earth's
early history. as revealed by geology one
cannot argue that n aterial globes must be
inhabited. Unoccupied space, ifeless mil
lerniums and worlds uninhabited all fall
into the same category of unexplained use
But, If We narrow the question, and In
quire as to the possibility Of forms Of life
such as we are acquainted with upon the
earth, the case is different. We are able
to say at once, and with absolute con-
fidence. that there are only two among all
the heavenly bodies observable with our
present telescopes upon which anything like
terrestrial life could possibly exist The
two are Venus and Mars: upon all the rest
the conditions are clearly too different from
our own.
AS to the planet Venus. we need say very
little here. In diameter, mass, density and
the force of gravity upon her surface she
Is the earth's twin sister. She is so muca
nearer than we are to the sun that she re-
ceives from him almost twice as much
heat and light as we do, but as to the char
acter OF her surface, we know almost
nothing. Unquestionable observations
prove that she mas a denser atmosphere
than ours. and 1t Is probably always filled
with cloud.
Pretty Cold Place.
With Mars the case is different; We know
n ore about him than we do about any
other heavenly body. the moon excepted.
Since the planets distance from the sun
averages something more than once and a
half that of the earth. 1t Is certain that
Mars receives less than half as much solar
heat and light as we dO-an unquestionable
and most important fact.
In the next place. we know that the d.
ameter of Mars Is about forty-two hundred
miles tsomeWhat more than half that of
the earth), and that 1t rotates in 24h.37m.
22-6jS. around an axis so situated that the
planets equator Is inclined about twenty
four degrees to the plane of its orbit. This
Is so nearly the same as the inclination
OF the earths equator that We safely infer
that Mars must have seasons very like
those of the earth. though notably modified
by the considerable variations In it's dis
tanoe from the sun at different parts of its
orbit.
In the third place, from the motions of
its two little moons. we can calculate with
certainty the weight or 'mass" of the
planet and we find ii to be less than one
ninth (3-2S tfat of the earth. From this
1t follows also that the planets average
density is q per cent that of the earth.
and the force of gravity upon its surface
Is not quite 3S per cent as great here.
man who here weighs 16O pounds would
there weigh only sixty pounds. II he were
able here to jump to a height of five feet.
there he could jump thirteen. So far as
this condition goes Marian, elephant
might be as agile as terrestrial deer.
Different Atmosphere.
Thus far there is no guesswork We
have stated knowledge, not speculation.
Once more. There are clear indications
of an atmosphere upon the planet. though
they are not such as to enable us to cal
crlate with certainty its extent and dem
sity. This atmosphere ought to be much
less extensive and dense than ours, on ac-
count of the lessened force of gravity, and
If the so-called "dynamical theory of
gases. now almost universally accepted
among physicists, Is true, 1t must be lit
tie body, like the moon. or Mars cannot
permanently retain an atmosphere like our
own.
The inference is borne out, too. by the
fact that clouds are only rarely observed
upon the planet. 80. '.r'''...-.si .
And now we come to a question of great
dif1culty-that of the planets temperature.
Since the planets atmosphere is certainly
not dense, it Is natural to conclude that the
temperature at Its surface. even If the suns
heat there were as intense as here, must be
practically the Sc me as that of places on
the earth where the density of the air is
cCrrespondingly low. namely at the tops
Of the lCftiest mountains, In the regions Of
perpetual snow. D., -.,, ~
And. recalling that on Mars the solar
radiation is less than half as intense as
here. the inference is almost Irresistible
that the temperature must be appallingly
low. 50 low that, as on the moon, water, IL
1t exists at all, can exist only as ice.
And yet, while many Astronomers my
self. for one-are disposed to think this
pr obably true. 1t Is only an inference, and
not certain one. Nor can 1t be denied
look very much like the deposit and melt
ing of polar SHOWS. the flow of water and
the growth Of vegetation.
Judgment Hangs Suspended.
1t may be. perhaps, as Flammarion has
suggested. that the planets atmosphere,
though rare, has some peculiar constitution
that makes it more effective as blanket"
tran our own in its power to retain the
solar heat; or. it may possibly have some
unknown source of heat: or, again. it may
be that Fay's modification of the 1ebular
hypothesis Is correct, and that Mars, in
stead of beirg an older planet than the
earth, as commonly supposed, may be
younger one. still retaining considerable of
it's original heat of condensation, and not
yet cooled down to a permanent tempera-
ture corresponding to its distance from the
sun.
But unless some cause operates to give it
an abnormal temperature, the discussion
need go no further. Life resembling that
upon the earth could not exist there.
time before
long, when we may have heat measuring
of sufficient delicacy to give
Us certain information whether the plan
cts temperature Is below zero, or is SIM
liar to that of our habitable earth. Till
then Judgment hangs suspended.
THE PUEBLO WOMEN.