A Journey in Other Worlds (12 page)

It soon presented the phase of a half moon, but the waviness of the straight line, as in the case of Venus and Mercury, showed that the size of the mountains must be tremendous compared with the mass of the body, some of them being obviously fifteen miles high. The intense blackness of the shadows, as on the moon, convinced them there was no trace of atmosphere.

"There being no air," said Cortlandt, "it is safe to assume there is no water, which helps to account for the great inequalities on the body's surface, since the mountains will seem higher when surrounded by dry ocean-bottom than they would if water came halfway up their sides. Undoubtedly, however, the main cause of their height is the slight effect of gravitation on an asteroid, and the fact that the shrinking of the interior, and consequent folding of the crust in ridges, may have continued for a time after there was no longer water on the surface to cut them down.

"The temperature and condition of a body," continued Cortlandt, "seem to depend entirely on its size. In the sun we have an incandescent, gaseous star, though its spots and the colour of its rays show that it is becoming aged, or, to be more accurate, advanced in its evolutionary development. Then comes a great jump, for Jupiter has but about one fourteen-hundredth of the mass of the sun, and we expect to find on it a firm crust, and that the planet itself is at about the fourth or fifth period of development, described by Moses as days. Saturn is doubtless somewhat more advanced. The earth we know has been habitable many hundreds of thousands or millions of years, though three fourths of its surface is still covered by water. In Mars we see a further step, three fourths of its surface being land. In Mercury, could we study it better, or in the larger satellites of Jupiter or Saturn, we might find a stepping-stone from Mars to the moon, perhaps with no water, but still having air, and being habitable in all other respects. In our own satellite we see a world that has died, though its death from an astronomical point of view is comparatively recent, while this little Pallas has been dead longer, being probably chilled through and through. From this I conclude that all bodies in the solar system had one genesis, and were part of the same nebulous mass. But this does not include the other systems and nebulae; for, compared with them, our sun, as we have seen, is itself advanced and small beside such stars as Sirius having diameters of twelve million miles." As they left Pallas between themselves and the sun, it became a crescent and finally disappeared.

Two days later they sighted another asteroid exactly ahead. They examined it closely, and concluded it must be Hilda, put down in the astronomies as No. 153, and having almost the greatest mean distance of any of these small bodies from the sun.

When they were so near that the disk was plainly visible to the unaided eye, Hilda passed between them and Jupiter, eclipsing it. To their surprise, the light was not instantly shut off, as when the moon occults a star, but there was evident refraction.

"By George!" said Bearwarden, "here is an asteroid that HAS an atmosphere." There was no mistaking it. They soon discovered a small ice-cap at one pole, and then made out oceans and continents, with mountains, forests, rivers, and green fields. The sight lasted but a few moments before they swept by, but they secured several photographs, and carried a vivid impression in their minds. Hilda appeared to be about two hundred miles in diameter.

"How do you account for that living world," Bearwarden asked Cortlandt, "on your theory of size and longevity?"

"There are two explanations," replied Cortlandt, "if the theory, as I still believe, is correct. Hilda has either been brought to this system from some other less matured, in the train of a comet, and been captured by the immense power of "Jupiter, which might account for the eccentricity of its orbit, or some accident has happened to rejuvenate it here. A collision with another minor planet moving in an orbit that crossed its own, or with the head of a large comet, would have reconverted it into a star, perhaps after it had long been cold. A comet may first have so changed the course of one of two small bodies as to make them collide. This seems to me the most plausible theory. Over a hundred years ago the English astronomer, Chambers, wrote of having found traces of atmosphere in some of these minor planets, but it was generally thought he was mistaken. One reason we know so little about this great swarm of minor planets is, that till recently none of them showed a disk to the telescope. Inasmuch as only their light was visible, they were indistinguishable from stars, except by their slow motion. A hundred years ago only three hundred and fifty had been discovered; our photographic star-charts have since then shown the number recorded to exceed one thousand."

Preparing To Alight

That afternoon Ayrault brought out some statistical tables he had compiled from a great number of books, and also a diagram of the comparative sizes of the planets. "I have been not a little puzzled at the discrepancies between even the best authors," he said, "scarcely any two being exactly alike, while every decade has seen accepted theories radically changed." Saying which, he spread out the result of his labours (shown on the following pages), which the three friends then studied. ----------------------------------------------------------------(1) Mean distance from sun in millions of miles (2) Semimajor axis of orbit, earth's distance as 1

(3) Eccentricity of orbit

(4) Planets inclination of orbit to elliptic

(5) Light at perihelion

(6) Light at apehelion

(7) Heat, earth as 1

(1) (2) (3) (4) (5) (6) (7)

Mercury... 36.0 0.387 0.2056 7@0'8" 10.58 4.59 6.67

Venus..... 67.2 0.723 0.0068 3@23'35" 1.94 1.91 1.91

The Earth. 92.9 1.000 0.068 0@0'0" 1.03 0.997 1.00

Mars......141.5 1.524 0.0933 1@51'2" 0.52 0.360 1.43

Asteroids 204.4 to 2.200 0.4 to 5@-35@ 325.2 to 3.500 0.34

Jupiter.. 483.3 5.203 0.0483 1@18'41" 0.04 0.034 0.037

Saturn... 886.0 9.539 0.0561 2@29'40" 0.012 0.0099 0.011

Uranus.. 1781.9 19.183 0.0463 0@46'20" 0.0027 0.0025 0.003

Neptune. 2791.6 30.055 0.0090 1@47'2" 0.0011 0.0011 0.001

-----------------------------------------------------------------(1) MOVEMENT IN ORBIT. Velocity compared with earth as 1. (2) MOVEMENT IN ORBIT. Period of revolution in years and days.

(3) MOVEMENT IN ORBIT. Orbital velocity in miles per second.

(4) Mean diameter in miles

(5) Surface compared with earth as 1.

(6) Volume compared with earth as 1.

(7) Mass compared with earth as 1.

Planets (1) (2) (3) (4) (5) (6) (7)

Mercury..... 0.88 23 to 35 1.6 3,000 0.14 0.056 0.13

Venus.....0.224 1/2 21.9 1.17 7,700 0.94 0.92 0.78

The Earth... 1.00 18.5 1.0 7,918 1.00 1.00 1.00

Mars........ 1.88 15.0 0.81 4,230 0.28 0.139 0.124

Asteroids... 3.29 .... .... From a few to 6.56

miles to 300

Jupiter..... 11.86 8.1 0.44 86,500 118.3 1309.00 316.0

Saturn...... 29.46 6.0 0.32 1,000 0.4 760.0 95.0

Uranus...... 84.02 4.2 0.23 31,900 16.3 65.0 14.7

Neptune.... 164.78 3.4 0.18 34,800 19.3 90.0 17.1

-----------------------------------------------------------------(1) Length of day. hrs. min. sec. (2) Length of seasons

(3) DENSITY Compared with earth as 1

(4) DENSITY Compared with water as 1

(5) FORCE OF GRAVITY AT SURFACE OF PLANET Compared with earth as 1.

(6) FORCE OF GRAVITY AT SURFACE OF PLANET Bodies fall in one second.

(7) Inclination of axis.

Planets (1) (2) (3) (4) (5) (6) (7)

Mercury. ........ ......... 1.24 7.17 0.85 13.7 .....

Venus... 23 21 22 ........ 0.92 5.21 0.83 13.4 53+

The Earth. ..... Spring, 93 1.00 5.67 1.00 16.09 23 1/2

Summer, 93

Terrestrial days Autumn, 90

Winter,89

Mars... 24 37 23 Spring, 191 0.96 2.54 0.38 6.2 27 1/2

Summer, 181

Martian days Autumn, 149

Winter, 147

Asteroids........................................................

Jupiter. 9 55 28 ......... 0.22 1.29 2.55 40.98 1 1/2

Saturn..10 29 17 ......... 0.13 0.63 1.15 18.53 27

Uranus. ....... ......... 0.18 1.41 0.91 14.6 102(?)

Neptune......... ......... 0.20 0 0.88 14.2 .....

-----------------------------------------------------------------"You see," Ayrault explained, "on Jupiter we shall need our apergetic outfits to enable us to make long marches, while on Saturn they will not be necessary, the increase in our weight as a result of that planet's size being considerably less than the usual load carried by the Roman soldier."

"I do not imagine," said Cortlandt, "we should long be troubled by gravitation without our apergetic outfits even on Jupiter, for, though our weight will be more than doubled, we can take off one quarter of the whole by remaining near the equator, their rapid rotation having apparently been given providentially to all the large planets. Nature will adapt herself to this change, as to all others, very readily. Although the reclamation of the vast areas of the North American Arctic Archipelago, Alaska, Siberia, and Antarctic Wilkes Land, from the death-grip of the ice in which they have been held will relieve the pressure of population for another century, at the end of that time it will surely be felt again; it is therefore a consolation to feel that the mighty planets Jupiter and Saturn, which we are coming to look upon as our heritage, will not crush the life out of any human beings by their own weight that may alight upon them."

Before going to bed that evening they decided to be up early the next day, to study Jupiter, which was already a brilliant object.

The following morning, on awakening, they went at once to their observatory, and found that Jupiter's disk was plainly visible to the naked eye, and before night it seemed as large as the full moon.

They then prepared to check the Callisto's headlong speed, which Jupiter's attraction was beginning to increase. When about two million miles from the great planet, which was considerably on their left, they espied Callisto ahead and slightly on their right, as Deepwaters had calculated it would be. Applying a mild repulsion to this--which was itself quite a world, with its diameter of over three thousand miles, though evidently as cold and dead as the earth's old moon--they retarded their forward rush, knowing that the resulting motion towards Jupiter would be helped by the giant's pull. Wishing to be in good condition for their landing, they divided the remainder of the night into watches, two going to sleep at a time, the man on duty standing by to control the course and to get photographic negatives, on which, when they were developed, they found two crescentshaped continents, a speckled region, and a number of islands. By 7 A. M., according to Eastern standard time, they were but fifty thousand miles from Jupiter's surface, the gigantic globe filling nearly one side of the sky. In preparation for a sally, they got their guns and accoutrements ready, and then gave a parting glance at the car. Their charge of electricity for developing the repulsion seemed scarcely touched, and they had still an abundant supply of oxygen and provisions. The barometer registered twenty-nine inches, showing that they had not lost much air in the numerous openings of the vestibule. The pressure was about what would be found at an altitude of a few hundred feet, part of the rarefaction being no doubt due to the fact that they did not close the windows until at a considerable height above Van Cortlandt Park.

They saw they should alight in a longitude on which the sun had just risen, the rocky tops of the great mountains shining like helmets in its rays. Soon they felt a sharp checking of their forward motion, and saw, from the changed appearance of the stars and the sun, that they had entered the atmosphere of their new home.

Not even did Columbus, standing at the prow of the Santa Maria, with the New World before him, feel the exultation and delight experienced by these latter-day explorers of the twenty-first century. Their first adventures on landing the reader already knows. Exploration And Excitement

When they awoke, the flowers were singing with the volume of a cathedral organ, the chant rising from all around them, and the sun was already above the horizon. Finding a deep natural spring, in which the water was at about blood-heat, they prepared for breakfast by taking a bath, and then found they had brought nothing to eat.

"It was stupid of us not to think of it," said Bearwarden, "yet it will be too much out of our way to return to the Callisto."

"We have two rifles and a gun," said Ayrault, "and have also plenty of water, and wood for a fire. All we need is game."

"The old excuse, that it has been already shot out, cannot hold here," said Cortlandt.

"Seeing that we have neither wings nor pneumatic legs, and not knowing the advantage given us by our rifles," added Bearwarden, "it should not be shy either. So far," he continued, "we have seen nothing edible, though just now we should not be too particular; but near a spring like this that kind must exist."

"The question is," said the professor, "whether the game like warm water. If we can follow this stream till it has been on the surface for some time, or till it spreads out, we shall doubtless find a huntsman's paradise."

"A bright idea," said Bearwarden. "Let's have our guns ready, and, as old Deepwaters would say, keep our weather eye open."

The stream flowed off in a southeasterly direction, so that by following it they went towards the volcanoes.

"It is hard to realize," said the professor, "that those mountains must be several hundred miles away, for the reason that they are almost entirely above the horizon. This apparent flatness and wide range of vision is of course the result of Jupiter's vast size. With sufficiently keen sight, or aided by a good glass, there is no reason why one should not see at least five hundred miles, with but a slight elevation."

"It is surprising," said Ayrault, "that in what is evidently Jupiter's Carboniferous period the atmosphere should be so clear. Our idea has been that at that time on earth the air was heavy and dense."