Earthlight (Arthur C. Clarke Collection) Read online

  Sadler was wondering what humorist had stamped NOT TO BE TAKEN OUT OF THE LOUNGE across the shapely lady on the cover of last month's Triplanet News when Wheeler came storming into the room.

  "What is it now?" asked Sadler. "Discovered another nova? Or just looking for a shoulder to weep on?"

  He rather guessed that the latter was the case, and that his shoulder would have to do in the absence of anything more suitable. By this time he had grown to know Wheeler quite well. The young astronomer might be one of the most junior members of the staff, but he was also the most memorable. His sarcastic wit, lack of respect for higher authority, confidence in his own opinions and general argumentativeness prevented him from hiding his light under a bushel. But Sadler had been told, even by those who did not like Wheeler, that he was brilliant and would go far. At the moment he had not used up the stock of good will created by his discovery of Nova Dra-

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  conis, which in itself would be enough to insure a reputation for the rest of his career.

  "I was looking for Wagtail; he's not in his office, and I want to lodge a complaint."

  "Secretary Wagnall," answered Sadler, putting as much reproof as he could into the correction, "went over to Hydro­ponics half an hour ago. And if I may make a comment, isn't it somewhat unusual for you to be the source, rather than the cause, of a complaint?"

  Wheeler gave a large grin, which made him look incredibly and disarmingly boyish.

  "I'm afraid you're right. And I know this ought to go through the proper channels, and all that sort of thing—but it's rather urgent. I've just had a couple of hours' work spoiled by some fool making an unauthorized landing."

  Sadler had to think quickly before he realized what Wheeler meant. Then he remembered that this part of the Moon was a restricted area: no ships were supposed to fly over the north­ern hemisphere without first notifying the Observatory. The blinding glare of ion rockets picked up by one of the great telescopes could ruin photographic exposures and play havoc with delicate instruments.

  "You don't suppose it was an emergency?" Sadler asked, struck by a sudden thought. "It's too bad about your work, but that ship may be in trouble."

  Wheeler had obviously not thought of this, and his rage in­stantly abated. He looked helplessly at Sadler, as if wondering what to do next. Sadler dropped his magazine and rose to his feet.

  "Shouldn't we go to Communications ?" he said. "They ought to know what's going on. Mind if I come along?"

  He was very particular about such points in etiquette, and never forgot that he was here very much on sufferance. Besides, it was always good policy to let people think they were doing you favors.

  Wheeler jumped at the suggestion, and led the way to Communications as if the whole idea had been his own. The signals office was a large, spotlessly tidy room at the highest level of the Observatory, only a few meters below the lunar

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  crust. Here was the automatic telephone exchange, which was the Observatory's central nervous system, and here were the monitors and transmitters which kept this remote scientific outpost in touch with Earth. They were all presided over by the duty signals officer, who discouraged casual visitors with a large notice reading: POSITIVELY AND ABSOLUTELY NO ADMITTANCE TO UNAUTHORIZED PERSONS.

  "That doesn't mean us," said Wheeler, opening the door. He was promptly contradicted by a still larger notice—THIS MEANS YOU. Unabashed, he turned to the grinning Sadler and added, "All the places you're really not supposed to enter are kept locked, anyway." Nevertheless he did not push open the second door, but knocked and waited until a bored voice called "Come in."

  The D.S.O., who was dissecting a spacesuit walkie-talkie set, seemed quite glad for the interruption. He promptly called Earth and asked Traffic Control to find out what a ship was doing in the Mare Imbrium without notifying the Observa­tory, While they were waiting for the reply to come back, Sadler wandered round the racks of equipment.

  It was really surprising that it needed so much apparatus just to talk to people, or to send pictures between Moon and Earth. Sadler, who knew how technicians loved explaining their work to anyone who showed real interest, asked a few questions and tried to absorb as many of the answers as he could. He was thankful that by this time no one bothered to wonder if he had any ulterior motives and was trying to find if they could do their jobs for half the money. They had ac­cepted him as an interested and inquisitive audience of one, for it was quite obvious that many of the questions he asked could have no financial significance.

  The reply from Earth came through on the auto-printer soon after the D.S.O. had finished his swift conducted tour. It was a slightly baffling message:

  FLIGHT NON-SCHEDULED. GOVERNMENT BUSINESS. NO NOTIFICATION ISSUED. FURTHER LANDINGS ANTICIPATED. INCONVENIENCE REGRETTED.

  Wheeler looked at the words as if he could not believe his eyes. Until this moment, the skies of the Observatory had been

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  sacrosanct. No abbot facing the violation of his monastery could have been more indignant.

  "They're going to keep it up!" he spluttered. "What about our program?"

  "Grow up, Con," said the signals officer indulgently. "Don't you listen to the news ? Or have you been too busy looking at your pet nova? This message means just one thing. There's something secret going on out in the Mare. I'll give you one guess."

  "I know," said Wheeler. "There's another of those hush-hush expeditions looking for heavy ores, in the hope that the Federation won't find out. It's all so damn childish."

  "What makes you think that's the explanation?" asked Sadler sharply.

  "Well, that sort of thing's been going on for years. Any bar In town will give you all the latest gossip."

  Sadler hadn't been "into town" yet—as the trip to Central City was called—but he could well believe this. Wheeler's ex­planation was highly plausible, particularly in view of the current situation.

  "We'll just have to make the best of it, I suppose," said the D.S.O., attacking his walkie-talkie again. "Anyway, there's one consolation. All this is going on to the south of us—the other side of the sky from Draco. So it won't really interfere with your main work, will it?"

  "I suppose not," Wheeler admitted grudgingly. For a mo­ment he seemed quite downcast. It was not—far from it— that he wanted anything to interfere with work. But he had been looking forward to a good fight, and to have it snatched out of his hands like this was a bitter disappointment.

  It needed no knowledge of the stars to see Nova Draconh now. Next to the waxing Earth, it was by far the brightest object in the sky. Even Venus, following the sun into the east, was pale compared to this arrogant newcomer. Already it had begun to cast a distinct shadow and it was still growing in brilliance.

  Down on Earth, according to the reports coming over the radio, it was clearly visible even in the daytime. For a little

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  while it had crowded politics off the front page, but now the pressure of events was making itself felt again. Men could not bear to think of eternity for long; and the Federation was only light-minutes, not light-centuries, away.

  Chapter V

  there were still those who believed that Man would have been happier had he stayed on his own planet; but it was rather too late, now, to do anything about that. In any case, had he remained on Earth, he would not have been Man. The rest­lessness that had driven him over the face of his own world, that had made him climb the skies and plumb the seas, would not be assuaged while the Moon and planets beckoned to him across the deeps of space.

  The colonization of the Moon had been a slow, painful, sometimes tragic and always fabulously expensive enterprise. Two centuries after the first landings, much of Earth's giant satellite was still unexplored. Every detail had, of course, been mapped from space, but more than half that craggy globe had never been examined at close quarters.

  Central City and the other bases that had been established with such labor were islands of life in an
immense wilderness, oases in a silent desert of blazing light or inky darkness. There had been many who had asked whether the effort needed to survive here was worthwhile, since the colonization of Mars and Venus offered much greater opportunities. But for all the problems it presented him, Man could not do without the Moon. It had been his first bridgehead in space, and was still the key to the planets. The liners that plied from world to world ob­tained all their propellent mass here, filling their great tanks with the finely divided dust which the ionic rockets would spit out in electrified jets. By obtaining that dust from the Moon, and not having to lift it through the enormous gravity field of Earth, it had been possible to reduce the cost of space-travel more than ten-fold. Indeed, without the Moon as a re-

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  fueling base, economical space-flight could never have been achieved.

  It had also proved, as the astronomers and physicists had predicted, of immense scientific value. Freed at last from the imprisoning atmosphere of Earth, astronomy had made giant strides, and indeed there was scarcely a branch of science that had not benefited from the lunar laboratories. Whatever the limitations of Earth's statesmen, they had learned one lesson well. Scientific research was the lifeblood of civilization; it was the one investment that could be guaranteed to pay dividends for eternity. . . .

  Slowly, with countless heartbreaking setbacks, man had discovered how to exist, then to live, and at last to flourish on the Moon. He had invented whole new techniques of vacuum engineering, of low-gravity architecture, of air and temperature control. He had defeated the twin demons of the lunar day and the lunar night, though always he must be on the watch against their depredations. The burning heat could expand his domes and crack his buildings; the fierce cold could tear apart any metal structure not designed to guard against con­tractions never encountered on Earth. But all these problems had, at last, been overcome.

  All novel and ambitious enterprises seem much more hazard­ous and difficult from afar. So it had proved with the Moon. Problems that had appeared insuperable before the Moon was reached had now passed into lunar folklore. Obstacles that had disheartened the first explorers had been almost forgotten. Over the lands where men had once struggled on foot, the monocabs now carried the tourists from Earth in luxurious comfort. . . .

  In a few respects, conditions on the Moon had helped rather than hindered the invaders. There was, for example, the ques­tion of the lunar atmosphere. On Earth it would have counted as a good vacuum, and it had no appreciable effect on astro­nomical observations. It was quite sufficient, however, to act as a very efficient shield against meteors. Most meteors are blocked by Earth's atmosphere before they get to within a hundred kilometers of the surface; they have been checked, in other words, while traveling through air no denser than the Moon's. Indeed, the Moon's invisible meteor shield is even

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  more effective than Earth's, since thanks to the low lunar gravity it extends much farther into space.

  Perhaps the most astonishing discovery of the first explorers was the existence of plant life. It had long been suspected, from the peculiar changes of light and shade in such craters as Aristarchus and Eratosthenes, that there was some form of vegetation on the Moon, but it was difficult to see how it could survive under such extreme conditions. Perhaps, it was sur­mised, a few primitive lichens or mosses might exist, and it would be interesting to see how they managed to do it.

  The guess was quite wrong. A little thought would have shown that any lunar plants would not be primitive, but would be highly specialized—extremely sophisticated, in fact, so that they could cope with their hostile environment. Primitive plants could no more exist on the Moon than could primitive Man.

  The commonest lunar plants were plump, often globular growths, not unlike cacti. Their horny skins prevented the loss of precious water, and were dotted here and there with trans­parent "windows" to let sunlight enter. This astonishing im­provisation, surprising though it seemed to many, was not unique. It had been evolved independently by certain desert plants in Africa, faced with the same problem of trapping sun­light without losing water.

  The unique feature of the lunar plants, however, was their ingenious mechanism for collecting air. An elaborate system of flaps and valves, not unlike that by which some sea creatures pump water through their bodies, acted as kind of compressor. The plants were patient; they would wait for years along the great crevasses which occasionally gush forth feeble clouds of carbon or sulphur dioxides from the Moon's interior. Then the flaps would go frantically to work, and the strange plants would suck into their pores every molecule that drifted by, before the transient lunar mist dispersed into the hungry near-vacuum which was all the atmosphere remaining to the Moon.

  Such was the strange world which was now home to some thousands of human beings. For all its harshness, they loved it and would not return to Earth, where life was easy and therefore offered little scope for enterprise or initiative. Indeed, the lunar colony, bound though it was to Earth by economic ties, had more

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  in common with the planets of the Federation. On Mars, Venus, Mercury and the satellites of Jupiter and Saturn, men were fight­ing a frontier war against Nature, very like that which had won the Moon. Mars was already completely conquered; it was the only world outside Earth where a man could walk in the open without the use of artificial aids. On Venus, victory was in sight, and a land surface three times as great as Earth's would be the prize. Elsewhere, only outposts existed: burning Mercury and the frozen outer worlds were a challenge for future cen­turies.

  So Earth considered. But the Federation could not wait, and Professor Phillips, in complete innocence, had brought its im­patience to the breaking point. It was not the first time that a scientific paper had changed the course of history, and it would not be the last.

  Sadler had never seen the pages of mathematics that had caused all the trouble, but he knew the conclusions to which they led. He had been taught many things in the six months that had been abstracted from his life. Some he had learned in a small, bare classroom with six other men whose names he had never been told, but much knowledge had come to him in sleep or in the dreamy trance-state of hypnosis. One day, perhaps, it would be withdrawn from him by the same techniques. The face of the Moon, Sadler had been told, consists of two distinct kinds of terrain—the dark areas of the so-called Seas, and the bright re­gions which are usually higher in elevation and much more mountainous. It is the bright areas which are pitted with the countless lunar craters, and appear to have been torn and blasted by eons of volcanic fury. The Seas, by contrast, are flat and relatively smooth. They contain occasional craters and many pits and crevasses, but they are incomparably more irregular than the rugged highlands.

  They were formed, it seems, much later than the mountains and crater chains of the Moon's fiery youth. Somehow, long after the older formations had congealed, the crust melted again in a few areas to form the dark, smooth plains that are the Seas. They contain the wrecks of many older craters and mountains that have been melted down like wax, and their coasts are

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  fringed with half-destroyed cliffs and ringed plains that barely escaped total obliteration.

  The problem which had long engaged scientists, and which Professor Phillips had solved, was this: Why did the internal heat of the Moon break out only in the selected areas of the Seas, leaving the ancient highlands untouched?

  A planet's internal heat is produced by radioactivity. It seemed to Professor Phillips, therefore, that under the great Seas must be rich deposits of uranium and its associated elements. The ebb and flow of tides in the Moon's molten interior had somehow produced these local concentrations, and the heat they had generated through millennia of radioactivity had melted the surface features far above them to form the Seas.

  For two centuries, men had gone over the face of the Moon with every conceivable measuring instrument. They had set its interior trembling with artificial earthquakes;
they had probed it with magnetic and electric fields. Thanks to these observa­tions, Professor Phillips had been able to put his theory on a sound mathematical basis.

  Vast lodes of uranium existed far below the Seas. Uranium itself was no longer of the vital importance that it had been in the twentieth and twenty-first centuries, for the old fission piles had long since given way to the hydrogen reactor. But where there was uranium, the heavy metals would be found as well.

  Professor Phillips had been quite sure that his theory had no practical applications. All these great deposits, he had carefully pointed out, were at such depths that any form of mining would be totally out of the question. They were at least a hundred kilometers down—and the pressure in the rock at that depth was so great that the toughest metal would flow like a liquid, so that no shaft or bore-hole could stay open even for an instant.