Space And Mars
:
LAST OF EARTH
Never before had the travellers observed the stars and planets
under such favourable conditions. No air or clouds intervened,
and as the Callisto did not revolve on its axis there was no
necessity for changing the direction of the glasses. After an
hour of this interesting work, however, as it was already late at
the longitude they had left on earth, and as they knew they had
many days in space before them, they prep
red to go to bed. When
ready, they had only to pull down the shades; for, as apergy was
not applied to them, but only to the Callisto, they still looked
upon the floor as down, and closed the heavy curtains to have
night or darkness. They found that the side of the Callisto
turned constantly towards the sun was becoming very warm, the
double-toughened glass windows making it like a greenhouse; but
they consoled themselves with the thought that the sun's power on
them was hourly becoming less, and they felt sure the double
walls and thick upholstery would protect them almost anywhere
within the solar system from the intense cold of space.
"We could easily have arranged," said Ayrault, for night and day
on alternate sides of the Callisto by having strips of metal
arranged spirally on the outside as on the end of an arrow.
These would have started us turning as slowly as we like, since
we passed through the atmosphere at a comparatively low rate of
speed."
"I am afraid," said Cortlandt, "the motion, however slow, would
have made us dizzy. It would be confusing to see the heavens
turning about us, and it would interfere with using the glasses."
The base and one side of the Callisto had constant sunshine,
while the other side and the dome were in the blackest night.
This dome, on account of its shape, sky windows, and the
completeness with which it could be isolated, was an ideal
observatory, and there was seldom a time during their waking
hours for the rest of the journey when it was not occupied by
one, two, or all the observers.
"There is something marvellous," said Cortlandt, "about the
condition of space. Its absolute cold is appalling, apparently
because there is nothing to absorb heat; yet we find the base of
this material projectile uncomfortably warm, though, should we
expose a thermometer in the shade in front, we know it would show
a temperature of three hundred to four hundred degrees below
zero--were the instrument capable of recording it."
Artificial darkness having been obtained, the travellers were
soon asleep, Bearwarden's dreams being regaled with thoughts of
his company's triumph; Ayrault's, naturally, with visions of
Sylvia; while Cortlandt frequently started up, thinking he had
already made some great astronomical discovery.
About 9 A. M., according to seventy-fifth meridian time, the
explorers awoke feeling greatly refreshed. The tank in which the
liquefied oxygen was kept automatically gave off its gas so
evenly that the air remained normal, while the lime contained in
cups absorbed the carbon dioxide as fast as they exhaled it.
They had darkened those windows through which the sun was
actually pouring, for, on account of the emptiness of the
surrounding ether and consequent absence of diffusion of light,
nothing but the inky blackness of space and the bright stars
looked in at the rest. On raising the shades they got an idea of
their speed. A small crescent, smaller than the familiar moon,
accompanied by one still tinier, was all that could be seen of
the earth and its satellite.
"We must," said Bearwarden, "be moving at the rate of nearly a
million miles an hour, from the way we have travelled."
"We must be doing fully a million," replied Cortlandt, "for by
this time we are pretty well in motion, having got a tremendous
start when so near the moon, with it and the earth in line."
By steering straight for Jupiter, instead of for the place it
would occupy ten days later, they knew they would swing past, for
the giant planet, being in rapid motion, would advance; but they
did not object to this, since it would give them a chance to
examine their new world in case they wished to do so before
alighting; while, if they preferred to land at once, they could
easily change their course by means of the moons, the fourth,
from which their car was named, being the one that they knew
would be of most use. Their tremendous speed showed them they
should have time for exploration on their arrival, and that they
would reach their destination sooner than they had expected. The
apergetic force being applied, as we have seen, only to the
Callisto, just as power in starting is exerted on a carriage or
railway car and only through it to the passengers, Ayrault and
his companions had no unusual sensation except loss of weight,
for, when they were so far from the earth, its attraction was
very slight, and no other planet was near enough to take its
place. After breakfast, wishing to reach the dome, and realizing
that it would be unnecessary to climb, each in turn gave a slight
spring and was obliged to put up his hands to avoid striking the
roof. In the cool quiet of the dark dome it was difficult to
believe that only twenty feet away the sun was shining with such
intensity upon the metal base as to make it too hot on the inside
to touch without gloves.
The first thing that attracted their attention was the size and
brilliance of Mars. Although this red planet was over forty
million miles from the earth when they started, they calculated
that it was less than thirty million miles from them now, or five
millions nearer than it had ever been to them before. This
reduction in distance, and the clearness of the void through
which they saw it, made it a splendid sight, its disk showing
clearly. From hour to hour its size and brightness increased,
till towards evening it looked like a small, full moon, the sun
shining squarely upon it. They calculated that on the course
they were moving they should pass about nine hundred thousand
miles to the right or behind it, since it was moving towards
their left. They were interested to see what effect the mass of
Mars would have on the Callisto, and saw here a chance of still
further increasing their speed. Notwithstanding its tremendous
rate, they expected to see the Callisto swerve from its straight
line and move towards Mars, whose orbital speed of nine hundred
miles a minute they thought would take it out of the Callisto's
way, so that no actual collision would occur even if their
air-ship were left to her own devices.
Towards evening they noticed through their glasses that several
apparently island peaks in the southern hemisphere, which was
turned towards them, became white, from which they concluded that
a snow-storm was in progress. The south polar region was also
markedly glaciated, though the icecap was not as extensive as
either of those at the poles of the earth.
"As the Martian winters must be fully as severe as ours," said
Cortlandt, "on account of their length, the planet's distance
from the sun, and the twenty-seven and a half degrees inclination
of its axis, we can account for the smallness of its ice-caps
only by the fact that its oceans cover but one fourth of its
surface instead of three quarters, as on the earth, and there is
consequently a smaller evaporation and rain and snow-fall."
They were too much interested to think of sleeping that night,
and so, after dining comfortably returned to their observatory.
When within four million miles of Mars the Callisto began to
swerve perceptibly, its curve, as when near the moon beginning
with a spiral. They swung on unconcernedly, however, knowing
they could check their approach at any time. Soon Mars appeared
to have a diameter ten times as great as that of the moon, and
promised shortly to occupy almost one side of their sky.
"We must be on the lookout for the satellites," said Cortlandt;
"a collision with either would be worse than a wreck on a desert
island."
They therefore turned their glasses in the direction of the
satellites.
"Until Prof. Hall, at Washington, discovered the two satellites
in 1877," he continued, "Mars was supposed to be without moons.
The outer one, Deimos, is but six miles in diameter, and revolves
about its primary in thirty hours and eighteen minutes, at a
distance of fourteen thousand six hundred miles. As it takes but
little longer to complete a revolution than Mars does to rotate
on its axis, it remains in the Martial sky one hundred and
thirty-two hours between rising and setting, passing through all
the phases from new moon to full and back again four times; that
is, it swings four times around Mars before going below the
horizon. It is one of the smallest bodies discovered with a
telescope. The inner one, Phobos, is considerably larger, having
a diameter of about twenty miles. It is but twenty-seven hundred
miles from Mars's surface, and completes its revolution in seven
hours and thirty-eight minutes, which is shorter than any other
known period, Jupiter's nearest moon being the next, with eleven
hours and fifty- nine minutes. It thus revolves in less than a
third of the time Mars takes to rotate, and must consequently
rise in the west and set in the east, as it is continually
running ahead of the surface of the planet, though the sun and
all the other stars rise and set on Mars in the same way as on
the earth."
When about fifteen thousand miles from Mars, they sighted Deimos
directly ahead, and saw that they should pass on its left--i. e.,
behind--for it was moving across them. The sun poured directly
upon it, making it appear full and showing all its features.
There were small unevennesses on the surface, apparently seventy
or a hundred feet high, which were the nearest approach to
mountains, and they ran in ridges or chains. There were also
unmistakable signs of volcanic action, the craters being large
compared with the size of the planet, but shallow. They saw no
signs of water, and the blackness of the shadows convinced them
there was no air. They secured two instantaneous photographs of
the little satellite as the Callisto swept by, and resumed their
inspection of Mars. They noticed red and brownish patches on the
peaks that had that morning turned white, from which they
concluded that the show had begun to melt under the warm spring
sun. This strengthened the belief they had already formed, that
on account of its twenty-seven and a half degrees inclination the
changes in temperature on Mars must be great and sudden. So
interested were they with this, that they did not at first see a
large and bright body moving rapidly on a course that converged
with theirs.
"We must be ready to repel boarders," said Bearwarden, observing
it for the first time and fixing his glass upon it. "That must
be Phobos."
Not ten miles off they beheld Mars's inner moon, and though their
own speed caused them to overtake and rush by it like a
whirlwind, the satellite's rapid motion in its orbit, in a course
temporarily almost parallel with theirs, served to give them a
chance the better to examine it. Here the mountain ranges were
considerably more conspicuous than on Deimos, and there were
boulders and loose stones upon their slopes, which looked as if
there might at some time have been frost and water on its
surface; but it was all dry now, neither was there any air. The
evidences of volcanic action were also plainly visible, while a
noticeable flattening at the poles showed that the little body
had once rotated rapidly on its axis, though whether it did so
still they had not time to ascertain. When abreast of it they
were less than two miles distant, and they secured several
instantaneous impressions, which they put aside to develop later.
As the radius of Phobos's circle was far shorter than that of the
parabolic curve they were making, it began to draw away, and was
rapidly left behind. Applying the full apergetic force to Mars
and the larger moon, they shot away like an arrow, having had
their speed increased by the planet's attraction while
approaching it, and subsequently by repulsion.
"Either of those," said Bearwarden, looking back at the little
satellites, "would be a nice yacht for a man to explore space on.
He would also, of course, need a sun to warm him, if he wished to
go beyond this system, but that would not have to be a large
affair--in fact, it might be smaller than the planet, and could
revolve about it like a moon."
"Though a sun of that size," replied Cortlandt, "might retain its
heat for the time you wished to use it, the planet part would be
nothing like as comfortable as what we have here, for it would be
very difficult to get enough air-pressure to breathe on so small
a body, since, with its slight gravitation-pull, to secure
fifteen pounds to the square inch, or anything like it, the
atmosphere would have to extend thousands of miles into space, so
that on a cloudy day you would be in darkness. It would be
better, therefore, to have such a sun as you describe and
accompany it in a yacht or private car like this, well stocked
with oxygen and provisions. When passing through meteoric swarms
or masses of solid matter, collision with which is the most
serious risk we run, the car could follow behind its sun instead
of revolving around it, and be kept from falling into it by
partially reversing the attraction. As the gravitation of so
small a sun would be slight, counteracting it for even a
considerable time would take but little from the batteries."
"There are known to be several unclaimed masses," added Ayrault,
"with diameters of a few hundred yards, revolving about the earth
inside the orbit of the moon. If in some way two of these could
be brought into sufficiently violent collision, they would become
luminous and answer very well; the increase in bulk as a result
of the consolidation, and the subsequent heat, about serving to
bring them to the required size. Whenever this sun showed spots
and indications of cooling, it could be made to collide with the
solid head of some comet, or small asteroid, till its temperature
was again right; while if, as a result of these accretions, it
became unwieldy, it could be caused to rotate with sufficient
rapidity on its axis to split, and we should have two suns
instead of one."
"Bravo!" said Bearwarden. "There is no limit to what can be
done. The idea of our present trip would have seemed more
chimerical to people a hundred years ago than this new scheme
appears now."
Thus they sat and talked, or studied maps and star- charts, or
the stars themselves, while the hours quickly passed and they
shot through space. They had now a straight stretch of over
three hundred million miles, and had to cross the orbits of
innumerable asteroids on the way. The apparent size of the sun
had by this time considerably decreased, and the interior of the
Callisto was no longer uncomfortably warm. They divided the day
into twenty-four hours from force of habit, and drew the shades
tightly during what they considered night, while Bearwarden
distinguished himself as a cook.