Arthur Clarke: A Meeting with Medusa

The remaining hours of darkness were completely uneventful, until just before dawn. Because it came from the east, Falcon assumed that he was seeing the first faint hint of sunrise. Then he realised that it was twenty minutes too early for this, and the glow that had appeared along the horizon was moving toward him even as he watched. It swiftly detached itself from the arch of stars that marked the invisible edge of the planet, and he saw that it was a relatively narrow band, quite sharply defined. The beam of an enormous searchlight appeared to be swinging beneath the clouds.

Perhaps sixty miles behind the first racing bar of light came another, parallel to it and moving at the same speed. And beyond that another, and another, until all the sky flickered with alternating sheets of light and darkness.

By this time, Falcon thought, he had been inured to wonders, and it seemed impossible that this display of pure, soundless luminosity could present the slightest danger. But it was so astonishing, and so inexplicable, that he felt cold, naked fear gnawing at his self-control. No man could look upon such a sight without feeling like a helpless pygmy in the presence of forces beyond his comprehension. Was it possible that, after all, Jupiter carried not only life but also intelligence? And, perhaps, an intelligence that only now was beginning to react to his alien presence?

“Yes, we see it,” said Mission Control, in a voice that echoed his own awe. “We’ve no idea what it is. Stand by, we’re calling Ganymede.”

The display was slowly fading; the bands racing in from the far horizon were much fainter, as if the energies that powered them were becoming exhausted. In five minutes it was all over, the last faint pulse of light flickered along the western sky and then was gone. Its passing left Falcon with an overwhelming sense of relief. The sight was so hypnotic, and so disturbing, that it was not good for any man’s peace of mind to contemplate it too long.

He was more shaken than he cared to admit. The electrical storm was something that he could understand; but this was totally incomprehensible.

Mission Control was still silent. He knew that the information banks up on Ganymede were now being searched as men and computers turned their minds to the problem. If no answer could be found there, it would be necessary to call Earth, that would mean a delay of almost an hour. The possibility that even Earth might be unable to help was one that Falcon did not care to contemplate.

He had never before been so glad to hear the voice of Mission Control as when Dr Brenner finally came on the circuit. The biologist sounded relieved, yet subdued, like a man who has just come through some great intellectual crisis.

“Hello, Kon-Tiki. We’ve solved your problem, but we can still hardly believe it.

“What you’ve been seeing is bioluminescence, very similar to that produced by microorganisms in the tropical seas of Earth. Here they’re in the atmosphere, not the ocean, but the principle is the same.”

“But the pattern,” protested Falcon, “was so regular, so artificial. And it was hundreds of miles across!”

“It was even larger than you imagine; you observed only a small part of it. The whole pattern was over three thousand miles wide and looked like a revolving wheel. You merely saw the spokes, sweeping past you at about six-tenths of a mile a second. A second! ” Falcon could not help interjecting. “No animals could inOVC that fast!”

“Of course not. Let me explain. What you saw was triggered by the shock wave from Source Beta, moving at the speed of sound.”

“But what about the pattern?” Falcon insisted.

“That’s the surprising part. It’s a very rare phenomenon, but identical wheels of light, except that they’re a thousand times smaller, have been observed in the Persian Gulf and the Indian Ocean. Listen to this: British Company’s Patna, Persian Gulf, May 1880, 11:30 P.M… ‘an enormousous wheel, whirling round, the spokes of which appeared to brush ship along. The spokes were 200 or 300 yards long… each wheel contained about sixteen spokes…’ And here’s one from the Gulf of Oman, May 23, 1906: ‘The intensely bright luminescence approached us suddenly, shooting sharply defined light rays to the west in rapid succession, the beam from the searchlight of a warship… To the left of us, a fantastic fiery wheel formed itself, with spokes that reached as far as one could see. The whole wheel whirled around for two or three minutes.’ The archive computer on Ganymede dug up about five hundred cases. It would have printed out the lot if we hadn’t stopped it in time.”

“I’m convinced, but still baffled.”

“I don’t blame you. The full explanation wasn’t worked out until late in twentieth century. It seems that these luminous wheels are the results submarine earthquakes, and always occur in shallow waters where the waves can be reflected and cause standing wave patterns. Sometimes rotating wheels, sometimes, the ‘Wheels of Poseidon’. The theory was finally proved by making underwater explosions and photographing the results from a satellite. No wonder sailors used to be superstitious. Who would have believed a thing like this? ”

That was it, Falcon told himself. When Source Beta blew its top, it must have sent shock waves in all directions, through the compressed gas of the lower atmosphere, through the solid body of Jupiter itself. Meeting, crisscrossing, those waves must have cancelled here, reinforced there, the whole planet must have rung like a bell.

Yet the explanation did not destroy the sense of wonder and awe, he would never be able to forget those flickering bands of light, racing through unattainable depths of the Jovian atmosphere. He felt that he was not only on a strange planet, but in some magical realm between myth and reality.

This was a world where absolutely anything could happen, and no man possibly could guess what the future would bring.

And he still had a whole day to go.

When the true dawn finally arrived, it brought a sudden change of weather. Kon-Tiki was moving through a blizzard, waxen snowflakes were falling so much, that visibility was reduced to zero. Falcon began to worry about the weight that might be accumulating on the envelope. Then he noticed that flakes settling outside the windows quickly disappeared; Kon-Tiki’s continual outpouring of heat was evaporating them as swiftly as they arrived.

If he had been ballooning on Earth, he would also have worried about the possibility of collision. At least that was no danger here, any Jovian mountains were several hundred miles below him. And as for the floating islands of foam, hitting them would probably be like ploughing into slightly hardened soap bubbles.

Nevertheless, he switched on the horizontal radar, which until now had been completely useless; only the vertical beam, giving his distance from the invisible surface, had thus far been of any value. Then he had another surprise.

Scattered across a huge sector of the sky ahead were dozens of large and brilliant echoes. They were completely isolated from one another and apparently hung unsupported in space. Falcon remembered a phrase the earliest aviators had used to describe one of the hazards of their profession:

“clouds stuffed with rocks’. That was a perfect description of what seemed to lie in the track of Kon-Tiki.

It was a disconcerting sight, then Falcon again reminded himself that nothing really solid could possibly hover in this atmosphere. Perhaps it was some strange meteorological phenomenon. In any case, the nearest echo was about a hundred and twenty-five miles.