The Sentinel - Arthur C. Clarke [109]
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 move 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 India Company’s Patna, Persian Gulf, May 1880, 11:30 P.M.—‘an enormous luminous wheel, whirling round, the spokes of which appeared to brush the ship along. The spokes were 200 or 300 yards long . . . each wheel contained about sixteen spokes. . . .’ And here’s one from the Gulf of Omar, dated May 23, 1906: ‘The intensely bright luminescence approached us rapidly, shooting sharply defined light rays to the west in rapid succession, like the beam from the searchlight of a warship. . . .To the left of us, a gigantic 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 the twentieth century. It seems that these luminous wheels are the results of submarine earthquakes, and always