Chapter 4: 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.”