Evening star. [volume] (Washington, D.C.) 1854-1972, 1890-04-26
LIFE IN OTHER WORLDS.
care These Planets on Which There Il
Room for Life Actually Inhabited?''

Room for Life Actually Inhabited?''
WHAT PROF. GEORGE M. sEARLf THINKS ABOUT
THE PROBABILITIES OF ExIsrxScx In THE yoLAR
SYSTEM OUTSIDE OF THIS EARrH-Poryrs FROM
HIS LECTURE LAST EVENING.
Yesterday afternoon, at AS o'clock, Prof
George NJ. Searle's public course OF astronom-
lcai lectures was continued at the Catho-
lie University by q lecture on the SUBJ
Iect; "Are the Planets Inhabited?" The
question, he said which naturally occurs on
completing the survey of the planetary system
is: Are these planets, on which there is room
for life. actually inhabited?" It is question
more interesting to the general public than any
with which mere mathematics or physics have
to deal. Almost every astronomer has been
many times asked this question. At every sue
cessful increase in the size of telescopes men
vaguely hope that something may be done to
solve it. ''How much does this telescope mag
nlfy! Is the all-important question to the popu-
lar mind. That is not what the professional
astronomer is after. He wants to get more
hSht-to follow faint comets. TO discover new
nebu!e. But is it possible that telescopes can
ever magnify so much as to actually enable us
to see life on the planets? If IT could be seen
anywhere it would be seen on the moon; but
even here, In these most favorable circum-
are SO great as seemingly to preclude the hope
OF seeing any object as small as men, or even
as the largest animals.
No LIFE ON THE SUN AND MOON.
We have then to fall back upon the question,
"Are the planets. inhabitable?" as the only one
on which science is capable of giving us any
hight say the planets. for the sun may be
considered quite out of the question From
what we know about it at present we can be
quite sure that it Is not only intensely hot on
Its surface so hot as to destroy all possibilities
OF life, but that it is yet hotter toward the
center. The theory was maintained for long
time, on the great authority of Sir William
Herschel, that there might be a habltation In
the sun, but no one holds that now
The probabilities about the moon have been
given in previous lecture. The only posi-
bility of habitaton on the moon would be on
the other side which we do not see and it is ex-
tremely improbable that there is any differ
ence between one side and the other.
AS TO THE HABITABILITY OF THE OUTER PLANETS
In discussing the planets we shall begin with
the outer ones. With regard to Uranus and
Neptune the mere deficiency of light and heat
from the sun is not fatal objection to their
habltabillty. The atmospheric arrangements
can easily be such as to secure enough heat
and, in fact the planets themseles may by their
own warmth contribute great deal to this end.
Ana as Tor light all that is required is to make
eyes more sensitive or their pupils larger. The
light, after all, on Neptune, the most distant of
all, Is by no means insignificant. 1t is 700
times that of the full moon and equal to that
given by a large electric arc lamp at the dis
| lance of a few feet
1t has been said that these planets may possibly
be warm; In fact the danger is here. The prob
ability is that they are too warm: in fact too hot
to stand on. 1his is almost certainly the case
with Jupiter and Saturn. These are probably
especially Jupiter, decidedly incandescent and
serve as suns, or, at least, as furnaces, to the
satellites that circle around them. The satel-
Htes OF these four outer planets however, give
much more promising field for speculation
There Is 10 reason why any one of them, or in
fact all may not be now in habltable state.
| Much has been said of the beauty of the Sat-
urnian system as seen from the planet itself.
| The view from it's outer satellite, Japetus
which lies outside of the plane of the ring,
would certainly be magnificent, perhaps finer
than the view of the ring from Saturn itself.
THE INNER PLANETS.
We now come in our inward course to the
planet Mars. Here we have more positive
signs OF habitabiity than in any others of our
system. We have land and water, seasons like
| our own, and, in fact, planet similar to the
| earth. The climate, indeed, seems to be
warmer on the whole than our own, in spite of
its greater distance from the sun, but if any
| thing we should say that the most favorable
period for hRbitability on this planet was pass
| Ing away. The indications are that the seas
are drying up and the atmosphere disappear
ing. As to Venus and Mercury we can hardly
form any decided opinion, but it seems most
likely that they are in the state that the earth
was in in some of its geological ages in which
it was fitted to be the abode of vegetable life
| and OF some animal organism, but not Of the
higher forms.
SUMMING Up THE EVIDENCE.
The evidence, then, as a whoielis against the
actual habitability of most Of the planets of
our system, but would it not suffice to satisfy
the mind Of those who crave after a plurality
of worlds to believe that all the planets,
though not perhaps inhabited at present, have
been or will be2 The argument from the
habitation to the inhabitant is stronger if we
put il in this form. If we see some conditions
indicating convenience to life, though they be
| imperfect or incomplete, We can say that
| though there be no life there now there NAV
| have been or there may be in the future Ii
| we see house with only its framework up we
| say. "No one lives there now, but it lie being
| built for some one to live in," and when we see
a house In ruins we say, Somebody lived there
once" Now this Is very plausible and 1 think
| can be held as probable. The teaching Of
| geology is that the earth was a long time
uninhabitable. and we can hardly shut
| our eyes to the conclusion that from
the action of natural causes alone
| 1t would at some time in the distant future be-
NoiAO tuo history OF
| the earth is probably the history of the other
| planets if they are to be allowed to develop in
| natural way. What portion of the total life
of the planet is that in which it becomes habita-
| BILE by beings like ourselves we cannot very
well determine. The probability is that it is
| not a very great proportion of the whole period
| of development and decadence. So that if we
take planets in general, on which we can see
no signs one way or the other, the chances are
| very probably against its being just now in a
| habitable state. The number Of the satellites
is sufficiently great to warrant us in assuming
| that some one or two Of them at least may
/ probably now be fitted for intelligent life. OF
course the probability for life in the universe
| Is vastly increased if We can assume that the
| other stars have planets around them as well as
| our sun. And, indeed, the suns themselves
| may ultimately become inhabitable We know
at least one case of body sun-like In dimen.
sion which has either ceased to give light or
never gave 1T. 1t is only in exceptional cases
| that We can be aware of the existence of such
bodies, however numerous they may be.
1 Written THr FyrNrSa Sr.p