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
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(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
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(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 .....
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"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.