That left two alternatives—the planets, and the stars. Yet all the evidence was against intelligent life elsewhere in the Solar System—or indeed life of any kind except on Earth and Mars. The inner planets were too hot, the outer ones far too cold, unless one descended into their atmosphere to depths where the pressures amounted to hundreds of tons to the square inch.
So perhaps these visitors had come from the stars—yet that was even more incredible. As he looked up at the constellations strewn across the ebon lunar sky, Floyd remembered how often his fellow scientists had "proved" that interstellar travel was impossible. The journey from Earth to Moon was still fairly impressive; but the very nearest star was a hundred million times more distant. . . . Speculation was a waste of time; he must wait until there was more evidence,
"Please fasten your seat belts and secure all loose objects," said the cabin speaker suddenly. "Forty degree slope approaching."
Two marker posts with winking lights had appeared on the horizon, and the bus was steering between them. Floyd had barely adjusted his straps when the vehicle slowly edged itself over the brink of a really terrifying incline, and began to descend a long, rubble-covered slope as steep as the roof of a house. The slanting earthlight, coming from behind them, now gave very little illumination, and the bus's own floodlights had been switched on. Many years ago Floyd had stood on the lip of Vesuvius, staring into the crater; he could easily imagine that he was now driving down into it, and the sensation was not a very pleasant one.
They were descending one of the inner terraces of Tycho, and it leveled out again some thousand feet below. As they crawled down the slope, Michaels pointed out across the great expanse of plain now spread out beneath them.
"There they are," he exclaimed. Floyd nodded; he had already noticed the cluster of red and green lights several miles ahead, and kept his eyes fixed upon it as the bus edged its way delicately down the slope. The big vehicle was obviously under perfect control, but he did not breathe easily until it was once more on an even keel.
Now he could see, glistening like silver bubbles in the earthlight, a group of pressure domes—the temporary shelters housing the workers on the site. Near these was a radio tower, a drilling rig, a group of parked vehicles, and a large pile of broken rock, presumably the material that had been excavated to reveal the monolith. This tiny camp in the wilderness looked very lonely, very vulnerable to the forces of nature ranged silently around it. There was no sign of life, and no visible hint as to why men had come here, so far from home.
"You can just see the crater," said Michaels. "Over there on the right—about a hundred yards from that radio antenna."
So this is it, thought Floyd, as the bus rolled past the pressure domes, and came to the lip of the crater. His pulse quickened as he craned forward for a better view. The vehicle began to creep cautiously down a ramp of hard-packed rock, into the interior of the crater. And there, exactly as he had seen it in the photographs, was TMA-1.
Floyd stared, blinked, shook his head, and stared again. Even in the brilliant earthlight, it was hard to see the object clearly; his first impression was of a flat rectangle that might have been cut out of carbon paper; it seemed to have no thickness at all. Of course, this was an optical illusion; though he was looking at a solid body, it reflected so little light that he could see it only in silhouette.
The passengers were utterly silent as the bus descended into the crater. There was awe, and there was also incredulity—sheer disbelief that the dead Moon, of all worlds, could have sprung this fantastic surprise.
The bus came to a halt within twenty feet of the slab and broadside on so that all the passengers could examine it. Yet, beyond the geometrically perfect shape of the thing, there was little to see. Nowhere were there any marks, or any abatement of its ultimate, ebon blackness. It was the very crystallization of night, and for one moment Floyd wondered if it could indeed be some extraordinary natural formation, born of the fires and pressures attending the creation of the Moon. But that remote possibility, he knew, had already been examined and dismissed.
At some signal, floodlights around the lip of the crater were switched on, and the bright earthlight was obliterated by a far more brilliant glare. In the lunar vacuum the beams were, of course, completely invisible; they formed overlapping ellipses of blinding white, centered on the monolith. And where they touched it, its ebon surface seemed to swallow them.
Pandora's box, thought Floyd, with a sudden sense of foreboding—waiting to be opened by inquisitive Man. And what will he find inside?
Chapter 13
The Slow Down
The main pressure dome at the TMA-1 site was only twenty feet across, and its interior was uncomfortably crowded. The bus, coupled to it through one of the two airlocks, gave some much-appreciated extra living room.
Inside this hemispherical, double-walled balloon lived, worked, and slept the six scientists and technicians now permanently attached to the project. It also contained most of their equipment and instruments, all the stores that could not be left in the vacuum outside, cooking, washing, and toilet facilities, geological samples and a small TV screen through which the site could be kept under continuous surveillance.
Floyd was not surprised when Halvorsen elected to remain in the dome; he stated his views with admirable frankness.
"I regard spacesuits as a necessary evil," said the Administrator. "I wear one four times a year, for my quarterly checkout tests. If you don't mind, I'll sit here and watch over the TV."
Some of this prejudice was now unjustified, for the latest models were infinitely more comfortable than the clumsy suits of armor worn by the first lunar explorers. They could be put on in less than a minute, even without help, and were quite automatic. The Mk V into which Floyd was now carefully sealed would protect him from the worst that the Moon could do, either by day or by night.
Accompanied by Dr. Michaels, he walked into the small airlock. As the throbbing of the pumps died away, and his suit stiffened almost imperceptibly around him, he felt himself enclosed in the silence of vacuum.
That silence was broken by the welcome sound of his suit radio.
"Pressure O.K., Dr. Floyd? Are you breathing normally?"
"Yes—I'm fine."
His companion carefully checked the dials and gauges on the outside of Floyd's suit. Then he said:
"O.K.—let's go."
The outer door opened, and the dusty moonscape lay before them, glimmering in the earthlight.
With a cautious, waddling movement, Floyd followed Michaels through the lock. It was not hard to walk; indeed, in a paradoxical way the suit made him feel more at home than at any time since reaching the Moon. Its extra weight, and the slight resistance it imposed on his motion, gave some of the illusion of the lost terrestrial gravity.
The scene had changed since the party had arrived barely an hour ago. Though the stars, and the half-earth, were still as bright as ever, the fourteen-day lunar night had almost ended. The glow of the corona was like a false moonrise along the eastern sky—and then, without warning, the tip of the radio mast a hundred feet above Floyd's head suddenly seemed to burst into flame, as it caught the first rays of the hidden sun.
They waited while the project supervisor and two of his assistants emerged from the airlock, then walked slowly toward the crater. By the time they had reached it, a thin bow of unbearable incandescence had thrust itself above the eastern horizon. Though it would take more than an hour for the sun to clear the edge of the slowly turning moon, the stars were already banished.
The crater was still in shadow, but the floodlights mounted around its rim lit the interior brilliantly. As Floyd walked slowly down the ramp toward the black rectangle, he felt a sense not only of awe but of helplessness. Here, at the very portals of Earth, man was already face to face with a mystery that might never be solved. Three million years ago, something had passed this way, had left this unknown and perhaps unknowable symbol of its purpose, and had retur
ned to the planets—or to the stars.
Floyd's suit radio interrupted his reverie. "Project supervisor speaking. If you'd all line up on this side, we'd like to take a few photos. Dr. Floyd, will you stand in the middle—Dr. Michaels—thank you . . . "
No one except Floyd seemed to think that there was anything funny about this. In all honesty, he had to admit that he was glad someone had brought a camera; here was a photo that would undoubtedly be historic, and he wanted copies for himself. He hoped that his face would be clearly visible through the helmet of the suit.
"Thanks, gentlemen," said the photographer, after they had posed somewhat self-consciously in front of the monolith, and he had made a dozen exposures. "We'll ask the Base Photo Section to send you copies."
Then Floyd turned his full attention to the ebon slab—walking slowly around it, examining it from every angle, trying to imprint its strangeness upon his mind. He did not expect to find anything, for he knew that every square inch had already been gone over with microscopic care.
Now the sluggish sun had lifted itself above the edge of the crater, and its rays were pouring almost broadside upon the eastern face of the block. Yet it seemed to absorb every particle of light as if it had never been.
Floyd decided to try a simple experiment; he stood between the monolith and the sun, and looked for his own shadow on the smooth black sheet. There was no trace of it. At least ten kilowatts of raw heat must be falling on the slab; if there was anything inside, it must be rapidly cooking.
How strange, Floyd thought, to stand here while—this thing—is seeing daylight for the first time since the Ice Ages began on Earth. He wondered again about its black color; that was ideal, of course, for absorbing solar energy. But he dismissed the thought at once; for who would be crazy enough to bury a sunpowered device twenty feet underground?
He looked up at the Earth, beginning to wane in the morning sky. Only a handful of the six billion people there knew of this discovery; how would the world react to the news when it was finally released?
The political and social implications were immense; every person of real intelligence—everyone who looked an inch beyond his nose—would find his life, his values, his philosophy, subtly changed. Even if nothing whatsoever was discovered about TMA-1, and it remained an eternal mystery, Man would know that he was not unique in the universe. Though he had missed them by millions of years, those who had once stood here might yet return: and if not, there might well be others. All futures must now contain this possibility.
Floyd was still musing over these thoughts when his helmet speaker suddenly emitted a piercing electronic shriek, like a hideously overloaded and distorted time signal. Involuntarily, he tried to block his ears with his spacesuited hands; then he recovered and groped frantically for the gain control of his receiver. While he was still fumbling four more of the shrieks blasted out of the ether; then there was a merciful silence.
All around the crater, figures were standing in attitudes of paralyzed astonishment. So it's nothing wrong with my gear, Floyd told himself; everyone heard those piercing electronic screams.
After three million years of darkness, TMA-1 had greeted the lunar dawn.
Chapter 14
The Listeners
A hundred million miles beyond Mars, in the cold loneliness where no man had yet traveled, Deep Space Monitor 79 drifted slowly among the tangled orbits of the asteroids. For three years it had fulfilled its mission flawlessly—a tribute to the American scientists who had designed it, the British engineers who had built it, the Russian technicians who had launched it. A delicate spider's-web of antennas sampled the passing waves of radio noise—the ceaseless crackle and hiss of what Pascal, in a far simpler age, had naïvely called the "silence of infinite space." Radiation detectors noted and analyzed incoming cosmic rays from the galaxy and points beyond; neutron and X-ray telescopes kept watch on strange stars that no human eye would ever see; magnetometers observed the gusts and hurricanes of the solar winds, as the Sun breathed million-mile-an-hour blasts of tenuous plasma into the faces of its circling children. All these things, and many others, were patiently noted by Deep Space Monitor 79, and recorded in its crystalline memory.
One of its antennas, by now unconsidered miracles of electronics, was always aimed at a point never far from the Sun. Every few months its distant target could have been seen, had there been any eye here to watch, as a bright star with a close, fainter companion; but most of the time it was lost in the solar glare.
To that far-off planet Earth, every twenty-four hours, the monitor would send the information it had patiently garnered, packed neatly into one five-minute pulse. About a quarter of an hour late, traveling at the speed of light, that pulse would reach its destination. The machines whose duty it was would be waiting for it; they would amplify and record the signal, and add it to the thousands of miles of magnetic tape now stored in the vaults of the World Space Centers at Washington, Moscow, and Canberra.
Since the first satellites had orbited, almost fifty years earlier, trillions and quadrillions of pulses of information had been pouring down from space, to be stored against the day when they might contribute to the advance of knowledge. Only a minute fraction of all this raw material would ever be processed; but there was no way of telling what observation some scientist might wish to consult, ten, or fifty, or a hundred years from now. So everything had to be kept on file, stacked in endless air-conditioned galleries, triplicated at the three centers against the possibility of accidental loss. It was part of the real treasure of mankind, more valuable than all the gold locked uselessly away in bank vaults.
And now Deep Space Monitor 79 had noted something strange—a faint yet unmistakable disturbance rippling across the Solar System, and quite unlike any natural phenomenon it had ever observed in the past. Automatically, it recorded the direction, the time, the intensity; in a few hours it would pass the information to Earth.
As, also, would Orbiter M 15, circling Mars twice a day; and High Inclination Probe 21, climbing slowly above the plane of the ecliptic; and even Artificial Comet 5, heading out into the cold wastes beyond Pluto, along an orbit whose far point it would not reach for a thousand years. All noted the peculiar burst of energy that had disturbed their instruments; all, in due course, reported back automatically to the memory stores on distant Earth.
The computers might never have perceived the connection between four peculiar sets of signals, from space-probes on independent orbits millions of miles apart. But as soon as he glanced at his morning report, the Radiation Forecaster at Goddard knew that something strange had passed through the Solar System during the last twenty-four hours.
He had only part of its track, but when the computer projected it on the Planet Situation Board, it was as clear and unmistakable as a vapor trail across a cloudless sky, or a single line of footprints over a field of virgin snow. Some immaterial pattern of energy, throwing off a spray of radiation like the wake of a racing speedboat, had leaped from the face of the Moon, and was heading out toward the stars.
PART THREE
BETWEEN PLANETS
Chapter 15
Discovery
The ship was still only thirty days from Earth, yet David Bowman sometimes found it hard to believe that be had ever known any other existence than the closed little world of Discovery. All his years of training, all his earlier missions to the Moon and Mars, seemed to belong to another man, in another life.
Frank Poole admitted to the same feelings, and had sometimes jokingly regretted that the nearest psychiatrist was the better part of a hundred million miles away. But this sense of isolation and estrangement was easy enough to understand, and certainly indicated no abnormality. In the fifty years since men had ventured into space, there had never been a mission quite like this.
It had begun, five years ago, as Project Jupiter—the first manned round trip to the greatest of the planets. The ship was nearly ready for the two-year voyage when, somewhat abruptly, the
mission profile had been changed.
Discovery would still go to Jupiter; but she would not stop there. She would not even slacken speed as she raced through the far-ranging Jovian satellite system. On the contrary—she would use the gravitational field of the giant world us a sling to cast her even farther from the Sun. Like a comet, she would streak on across the outer reaches of the solar system to her ultimate goal, the ringed glory of Saturn. And she would never return.
For Discovery, it would be a one-way trip—yet her crew had no intention of committing suicide. If all went well, they would be back on Earth within seven years—five of which would pass like a flash in the dreamless sleep of hibernation, while they awaited rescue by the still unbuilt Discovery II.
The word "rescue" was carefully avoided in all the Astronautics Agency's statements and documents; it implied some failure of planning, and the approved jargon was "re-acquisition." If anything went really wrong, there would certainly be no hope of rescue, almost a billion miles from Earth.
It was a calculated risk, like all voyages into the unknown. But half a century of research had proved that artificially induced human hibernation was perfectly safe, and it had opened up new possibilities in space travel. Not until this mission, however, had they been exploited to the utmost.
The three members of the survey team, who would not be needed until the ship entered her final orbit around Saturn, would sleep through the entire outward flight. Tons of food and other expendables would thus be saved; almost as important, the team would be fresh and alert, and not fatigued by the ten-month voyage, when they went into action.
Discovery would enter a parking orbit around Saturn, becoming a new moon of the giant planet. She would swing back and forth along a two-million-mile ellipse that took her close to Saturn, and then across the orbits of all its major moons. They would have a hundred days in which to map and study a world with eighty times the area of Earth, and surrounded by a retinue of at least fifteen known satellites - one of them as large as the planet Mercury.