“Good,” said Madeleine. “I think I can keep those figures in my head. I’ll become a veritable astronomer.”
Meanwhile, the speed of the Selenit was still accelerating, at such a rhythm that Madeleine was not the only once rendered uncomfortable by it. All the passengers were beginning to go pale and experience nausea.
“Garrick and Kito are pushing the engine too heard,” Lang observed. “They’re exceeding the tolerable limit of acceleration
The passengers’ malaise was all the more painful because the stability of the Selenit was far from perfect. The slight inequalities of the reactions of the various tubes of the engine were causing a kind of oscillation, which was becoming more intolerable by the minute. The walls were vibrating in spite of their insulation; the Selenit was filled by a dull growl that was transmitted by the steels of the tubes and the beams of the framework.
At one moment, the machine began to swivel like a top. That motion, which the passengers in the crew section could not appreciate by sight, nevertheless became sensible as soon as it acquired a certain rapidity. Scherrebek corrected it by means of the tangential tubes, and telephoned an instruction to Garrick and Kito to reduce the acceleration.
A few minutes later, he calculated that the velocity was great enough to compensate for the effects of gravitation, and gave the order to stop the engine. It was sufficient henceforth to allow the Selenit to travel by its own momentum to reach the limit of terrestrial attraction and pass into the influence of the Moon. The engine would not be activated again until the neutral zone between the two heavenly bodies was reached, when it would be necessary to correct any deviation of direction.
The passengers immediately felt liberated from their anguish. All noise, oscillation and libration had ceased. Noting any longer rendered the movement of the Selenit perceptible in any fashion, although it was prodigiously rapid.
Madeleine sat up abruptly “We’ve stopped,” she said.
She rose up into the air, as a balloon launched by a child would have done, and went to collide gently with the ceiling; then she descended again, slowly.
“What’s happening to me?” she asked, amazed.
The other passengers had got up in their turn, surprised, and were all rising up in the same fashion as Madeleine, some bumping into the ceiling and others into the walls. After a few moments they all found themselves reunited on the floor, crouching or lying down, no longer daring to budge.
“My friends,” said Lang, “I advise you only to move with the greatest precaution. We’re now subject to the effects of the diminution of weight, for which the accelerating action of the engine had compensated until now, drawing us away all the more rapidly as the Earth retained us less. Well, it’s easy to calculate how that attraction is reduced, knowing that it’s inversely proportional to the square of the distance. At the distance we’ve presently reached, approximately equal to the length of the terrestrial radius, what does a mass that weighs a kilo at the Earth’s surface weigh now? Since the distance from the Earth’s center has doubled, the weight has been reduced by two times two. A kilo only weighs a quarter of its former weight, which is to say, 250 grams.
“So, Madame, without wishing to offend you, what has happened to you is that you’ve become a very light woman, for if you weighed about sixty kilos on Earth, you now weigh no more than fifteen. In addition, when you allow yourself to fall through space, instead of increasing by ten meters a second, as it would on Earth, your velocity no longer increases by more than two meters fifty. That’s why you came down so softly after having leapt up to the ceiling.
“That considerable diminution of weight will also explain to you why we’ve been able to switch off the engine when we were still far from obtaining the critical velocity of twelve thousand meters a second necessary to liberate us from the terrestrial attraction; at the altitude we’ve reached the critical velocity is no more than 8,200 meters a second.”
“Forgive me, Doctor,” said Bojardo, “but for once, your science is in default.”
“What!”
“May I ask Madame Brifaut whether she has the sensation of still weighing anything, even fifteen kilos?”
“In truth, no,” Madeleine replied. “I feel immaterialized.”
“You’re right, Bojardo,” Lang exclaimed, “And I’m nothing but a fool. We’re no longer experiencing even the effects of terrestrial attraction. I’ll explain why, Madame. We’re traveling by courtesy of our own momentum, and if we weren’t subject to the gravitational field of the globe, our velocity would remain as invariable as that of any body not subject to any force. Not being in proximity to any heavenly body we wouldn’t be attracted by any, and we would be devoid of any weight, as we are at this moment.”
“But that’s not the case for us,” Madeleine objected, “since we’re in the neighborhood of the Earth.”
“Wait! The Earth, in attracting us, is slowing down our velocity. If we weren’t moving, we’d begin falling toward it with the acceleration of two meters fifty per second that I mentioned to you just now. As we have our own momentum, we’re continuing to draw away, except that our velocity is diminishing by two meters fifty per second; we’re yielding to the force that is soliciting us toward the center of the Earth, and in yielding to it, we’re ceasing to perceive it. To feel it, we’d have to be struggling against it—which is to say, propelling our vessel with a force equal to the terrestrial attraction and in the opposite direction, which would compensate exactly for the effects of gravity. At any rate, as we draw further away, that will become less intense and our deceleration will become less evident. That’s why our friend Bojardo is right….
“Not entirely, though,” Lang added, with a triumphant smile. We’re not absolutely deprived of weight, because our Selenit, which is a microcosm, possesses a certain mass and it is attracting us toward its center of gravity—oh, very feebly, no doubt, but sufficiently for us to be able to maintain ourselves on this floor, as we are.”
In fact, the passengers always came back to pose on the floor—but the slightest gesture launched them to the other side of the room.
Moving cautiously, Madeleine went to look through a porthole, and saw a fragment of black sky strewn with stars. Her movement had produced a slight oscillation, as if the Selenit were floating on a liquid.
“That’s odd,” she said. “The floor moved.”
“Which is to say that by moving, you displaced the Selenit’s center of gravity and changed its equilibrium position.”
Goffoël had consulted his watch.
“We’ve been traveling for forty-five minutes.”
“But we left at four o’clock in the afternoon and it’s already night,” said Madeleine, bewildered. “How did that happen?”
“What makes you think that it’s night?” asked Lang.
Madeleine pointed at the porthole. “Look—the sky’s black.”
“That’s simply because there’s no air, and no luminous diffusion is being produced; in the interplanetary void the sky appears black, and one can always see the stars in spite of the sun’s light.”
He headed for another porthole and said: “Look—there’s a violet reflection at the end of this tube. That’s the sunlight striking the Selenit obliquely from the front. We can’t perceive it from here, but Scherrebek and Galston must be blinded by its radiance.”
Scherrebek came down from the pilot’s cabin with Galston and let himself fall through the air like a soap bubble. At the same time, Kito and Garrick, who had received an order to come up, sprang like sylphs through the trapdoor in the floor. The entire mission was assembled.
“We have forty-eight hours of tranquility ahead of us,” said Scherrebek, “during which all we have to do is relax. I think that we can take advantage of it first of all by having dinner.”
“Sit down,” said Madeline. “I’ll serve you.”
She let herself fall into the food-store. Brifaut and Lang volunteered to help her, and the table was soon laid.
By means of a theodolite, Scherrebek determined the exact apparent diameter of the Moon, and deduced therefrom that the Selenit was ten thousand kilometers from the terrestrial globe.11
The explorers affected a cheerful attitude that was sometimes a trifle forced. They sometimes allowed their enthusiasm to run out, and a silence fell abruptly; everyone wondered, with a secret anguish, whether they would ever return to the Earth they had just quit.
But that did not last. Scherrebek, or one of his comrades, resumed talking, and the conversation was reestablished, in a tone of perfect confidence.
VI. Regarding the Moon
In addition to the periscopes in the pilot’s cabin, there were others in the crew section and the engine room. They were tubular devices of barrow width, which could be extended outside at will. Thus, the passengers were able to observe, in turn, the Sun, the Moon and the Earth.
With regard to the Sun, its glare was absolutely unsustainable; they were obliged to attenuate it by means of smoked glass and lead screens.
“I imagine,” said Brifaut, “that in the void, solar radiation is much richer in ultra-violet rays.”
“Indeed,” said Lang. “the terrestrial atmosphere absorbs and diffuses the blue and violet rays of the solar spectrum, and that’s the origin of the azure sky. Here, we wouldn’t be able to look at the Sun with the naked eye without being instantly blinded.”
Viewed from the Selenit, the Sun was displayed with much sharper contours, but also less regular, for its protuberances, which are merely enormous eruptions of incandescent gas, sometimes attain three or four hundred thousand kilometers in height, becoming visible. In spite of the screens, the star appeared intensely blue.
That hue was also that of the Moon, whose slender crescent was shining at about fifteen degrees from the Sun. They were seeing it at a greater angle than from the surface of the Earth, and as, in addition, no atmosphere interposed itself between the object and the gaze, the principal features of the part illuminated by the Sun were already very clearly distinguishable.
The strange sensation of lightness that the passengers experienced was not absolutely untroubled, for their hearts, accustomed to pumping a heavy fluid, were beating too forcefully and too precipitately; the explorers had congested faces. Nevertheless, the elasticity of the arteries reacted, and Uberaba, the company’s doctor, estimated that there was no danger of any serious accident.
By adapting the periscopes to a weak magnification, they were able to recognize in the northern part of the lunar crescent the large crater Endymion alongside the Humboldt Sea, and then Messala, Herzelius, Geminus, Burkhardt and Cleomedes, all extended into ellipses by the perspective.
“Above Cleomedes,” said Lang, “that large dark plain surrounded by mountains, which affects an oval form, like the craters, is the Sea of Crises. Beneath it, you can see the western edge of the Sea of Fecundity. The sun is rising over that plain, which is about six hundred kilometers wide. Note that when one refers to the western edge of the Moon one means the part facing the west of the Earth. It follows that if you took at the Moon with your head turned northwards, you have the west to your right and not to your left, as on Earth.”
Lang continued to list the craters descending southwards: Langrenus, Vendelinus and Petavius, the last-named remarkable for the great crevasse connecting its rampart to its central massif. Then came the extraordinarily tormented region of the south, which resembles the rough skin of an enormous animal covered in pustules.
“All the mountains on the surface of the Moon, then, have craters?” asked Madeleine.
“Not all, but a large number. The craters constitute a feature extremely widespread on the surface of our satellite. You can represent them as a plain sensibly lower than the surrounding region, surrounded by a circular or polygonal rampart, which sometimes attains an altitude of more than five thousand meters, at the center of which an isolated mountain generally rises, or a group of mountains higher than the rampart. The interior slope of the latter is abrupt, whereas the exterior slope is relatively gentle, and often scarcely stands above the plateau that serves it as a pedestal. There are, however, more or less rectilinear chains, like those baptized with names borrowed from the geography of our globe: the Alps, Apennines, Caucasus, etc.”
“The craters are those of volcanoes,” declared Brifaut.
“No,” said Bojardo, “we no longer believe that today, although one can’t deny their volcanic character. For my part, I’m a partisan of the theory of fissures and outflows. The lunar crust, having cooled and contracted more rapidly than the central mass, split into a multitude of little pieces, which can be compared to the squares of a chessboard, or, more precisely, to the hexagonal tiles that are used to pave the floor of kitchens, between those fragments, lava emerged, and formed the approximately circular ramparts that we observe.”
“You can’t be unaware,” said Uberaba, “that that theory encounters grave objections. How do you explain, for instance, if the phenomenon is due to the extension of the internal mass, that the interior plain of the crater is so profoundly sunk? And what is the origin of the central mountains?”
“As for the latter, they’re merely small craters formed afterwards, and as for the sunken bottom, it results from the void caused in the fluid nucleus of the Moon by the expulsion of lava at the surface.”
“That amounts to saying that you sometimes admit an expansion and sometimes a contraction of the lunar nucleus, according to which you need to justify a theory conceived a priori.”
“Perhaps,” said Bojardo, becoming irritated, “you hold to the implausible theory of bubbles?”
“Why is it implausible?” exclaimed Uberaba.
“Because bubbles a hundred kilometers in diameter can’t exist.”
“On Earth, undoubtedly; on the Moon, that’s another matter. As the gases expelled by the fluid mass tended to fray a passage through the thin and still pasty crust; submitted to enormous pressures, they weren’t incapable of rising above vast extents of denser matter, which the feeble lunar gravity didn’t, in any case, maintain strongly bound together. After the cooling, when the gases had ceased to act, the vault collapsed, uncovering the subjacent cavity.”
“Ingenious, but insufficient. You can’t explain the formation of the central mountains.”
“Debris of the vault.”
“But why isn’t that debris spread over the entire interior of the crater instead of accumulating at the center?”
“That can be explained,” retorted Uberaba. “I’ll prove it to you…”
“Personally,” said Espronceda, “I’m in favor of the bombardment theory.”
“Oh, yes—by aeroliths!” exclaimed Bojardo and Uberaba simultaneously and ironically.
“Can you deny that the surface of the Moon looks exactly like a bombarded terrain? If our satellite was formed at the expense of the terrestrial mass, one has to admit that all the matter of which it’s composed hasn’t always been assembled into a single globe, as it is today. At one time, the Earth had a myriad of tiny satellites, which circulated in much the same orbit, and which finished up agglomerating, falling upon one another. In the final period of that concentration, the Moon, already constituted and covered in a semi-solid crust, was exposed to a bombardment of aeroliths that hollowed out the cavities we observe. The central mountains of the craters are explained by matter splashing back after the impact.”
“It would have been necessary, then, for the lunar surface, which you assume to be pasty for the purposes of the explanation, to have solidified suddenly at the point
of the fall, immediately after the impact. Otherwise, the trace would have been effaced by the effect of reactions that are normally produced in the bosom of semi-fluid mater. Now, an impact might determine the liquefaction of solid matter by virtue of the resulting elevation of temperature, but never, so far as I know, the solidification of a fluid matter. You can see, therefore, that your theory is unsustainable.”12
Brifaut listened with amusement to these arguments, which proved, in sum, that none of the admitted theories regarding the formation of the lunar relief was secure from criticism.
“But is it impossible,” he ventured, “that the lunar craters, which resemble one another closely, from the greatest to the smallest, and which are so difficult to explain by means of purely natural causes, were constructed by intelligent beings?”
That reflection was greeted with bursts of laughter from all the other members of the mission, except Madeleine.
“Is my husband’s idea so ridiculous, then?” asked the young woman, vexed.
“Madame,” said Lang, “Monsieur Brifaut is not an astronomer. It would be quite excusable for him to sustain a hypothesis that has been seriously envisaged by scientists like Kepler, Schroeter and Gruithuysen, to whom we owe the first detailed observations of the Moon. But those authors didn’t possess the optical instruments or the photographic means of modern observatories. They didn’t appreciate the true dimensions of the lunar craters, nor did they notice their irregularities.”
“However,” observed Brifaut, unconvinced, “if the craters were for the Selenites something analogous to our ancient cities that are in ruins today, that would explain the deformations and irregularities of which you speak. If the Moon was once inhabited, but, as is probable, has been a dead world for a long time, the vestiges that we discover on its surface are the last traces of edifices that commenced collapsing millions of centuries ago.”
An International Mission to the Moon Page 5