Arthur Clarke - Earthlight

To Steffanson, it seemed ages before Wheeler called to him: “We’re nearly there! Look—dead ahead.” He went to the forward observation port, and stared across the cracked and broken ground. What a place to £ght for, he thought. But, of course, this barren wilderness of lava and meteor dust was only a disguise. Beneath it Nature had hidden treasures which men had taken two hundred years to find. Perhaps it would have been better had they never found them at all…

Still two or three kilometers ahead, the great metal dome was glinting in the sunlight. From this angle, it had an astonishing appearance, for the segment in shadow was so dark as to be almost invisible. At first sight, indeed, it looked as if the dome had been bisected by some enormous knife. The whole place looked utterly deserted, but within, Steffanson knew, it would be a hive of furious activity. He prayed that his assistants had completed the wiring of the power and sub-modulator circuits.

Steffanson began to adjust the helmet of his spacesuit, which he had not bothered to take off after entering the tractor. He stood behind Jamieson, holding on to one of the storage racks to steady himself.

“Now that we’re here,” he said, “the least I can do is to let you understand what’s happened.” He gestured toward the rapidly approaching dome. “This place started as a mine, and it still is. We’ve achieved something that’s never been done before—drilled a hole a hundred kilometers deep, right through the Moon’s crust and down into really rich deposits of metal.”

“A hundred kilometers!” cried Wheeler. “That’s ipossible! No hole could stay open under the pressure.”

“It can and does,” retorted Steffanson. “I’ve not time to discuss the technique, even if I knew much about it. But remember you can drill a hole six times as deep on the Moon as you can on Earth, before it caves in. However, that’s only part of the story. The real secret lies in what they’ve called pressure-mining. As fast as it’s sunk, the well is filled with a heavy silicone oil, the same density as the rocks around it. So no matter how far down you go, the pressure is the same inside as out, and there’s no tendency for the hole to close. Like most simple ideas, it’s taken a lot of skill to put it into practice. All the operating equipment has to work submerged, under enormous pressure, but the problems are being overcome and we believe we can get metals out in worthwhile quantities.

“The Federation learned this was going on about two years ago. We believe they’ve tried the same thing, but without any luck. So they’re determined that if they can’t share this hoard, we won’t have it either. Their policy seems to be one of bullying us into co-operation, and it’s not going to work.

“That’s the background, but now it’s only the less important part of the story. There are weapons here as well. Some have been completed and tested, others are waiting for the final adjustments. I’m bringing the key components for what may be the decisive one. That’s why Earth may owe you a greater debt than it can ever pay. Don’t interrupt—we’re nearly there and this is what I really want to tell you. The radio was not telling the truth about that twenty hours of safety. That’s what the Federation wants us to believe, and we hope they go on thinking we’ve been fooled. But we’ve spotted their ships, and they’re approaching ten times as fast as anything that’s ever moved through space before. I’m afraid they’ve got a fundamental new method of propulsion—I only hope it hasn’t given them new weapons as well. We’ve not much more than three hours before they get here, assuming they don’t step up their speed still further. You could stay, but for your own safety I advise you to turn around and drive like hell back to the Observatory. If anything starts to happen while you’re still out in the open, get under cover as quickly as possible. Go down into a crevasse—anywhere you can find shelter—and stay there until it’s all over. Now good-by and good luck. I hope we have a chance of meeting again, when this business is finished.”

Still clutching his mysterious packing case, Steffanson disappeared into the airlock before either of the men could speak. They were now entering the shadows of the great dome, and Jamieson circled it looking for an opening. Presently he recognized the spot through which he and Wheeler had made their entrance, and brought Ferdinand to a halt.

The outer door of the tractor slammed shut and the “Airlock Clear” indicator flashed on. They saw Steffanson running across toward the dome, and with perfect timing a circular port flipped open to let him in, then snapped shut behind him.

The tractor was alone in the building’s enormous shadow. Nowhere else was there any sign of life, but suddenly the metal framework of the machine began to vibrate at a steadily rising frequency. The meters on the control panel wavered madly, the lights dimmed, and then it was all over. Everything was normal again, but some tremendous field of force had swept out from the dome and was even now expanding into space. It left the two men with an overwhelming impression of energies awaiting the signal for their release. They began to understand the urgency of Steffanson’s warning. The whole deserted landscape seemed tense with expectation.

Across the steeply curving plain, the tiny beetle of the tractor raced for the safety of the distant hills. But could they be sure of safety even there? Jamieson doubted it. He remembered the weapons that science had made more than two centuries ago; they would be merely the foundation upon which the arts of war could build today. The silent land around him, now burning beneath the noonday sun, might soon be blasted by radiations fiercer still.

He drove forward into the shadow of the tractor, toward the ramparts of Plato, towering along the skyline like some fortress of the giants. But the real fortress was behind him, preparing its unknown weapons for the ordeal that must come.

It would never have happened had Jamieson been thinking more of driving and less of politics—though, in the circumstances, he could hardly be blamed. The ground ahead looked level and firm—exactly the same as the kilometers they had already safely traversed.

It was level, but it was no firmer than water. Jamieson knew what had happened the moment that Ferdinand’s engine started to race, and the tractor’s nose disappeared in a great cloud of dust. The whole vehicle tilted forward, began to rock madly to and fro, and then lost speed despite all that Jamieson could do. Like a ship foundering in a heavy sea, it started to sink. To Wheeler’s horrified eyes, they seemed to be going under in swirling clouds of spray. Within seconds, the sunlight around them had vanished. Jamieson had stopped the motor; in a silence broken only by the murmur of the air circulators, they were sinking below the surface of the Moon.

The cabin lights came on as Jamieson found the switch. For a moment, both men were too stunned to do anything but sit and stare helplessly at each other. Then Wheeler walked, not very steadily, to the nearest observation window. He could see absolutely nothing: no night was ever as dark as this. A smooth velvet curtain might have been brushing the other side of the thick quartz, for all the light that could penetrate it.

Suddenly, with a gentle but distinct bump, Ferdinand reached the bottom.

“Thank God for that,” breathed Jamieson. “It’s not very deep.”

“What good does that do us?” asked Wheeler, hardly daring to believe there was any hope. He had heard too many horrifying tales of these treacherous dust bowls, and the men and tractors they had engulfed.

The lunar dust bowls are, fortunately, less common than might be imagined from some travelers’ tales, for they can occur only under rather special conditions, which even now are not fully understood. To make one, it is necessary to start with a shallow crater pit in the right kind of rock, and then wait a few hundred million years while the temperature changes between night and day slowly pulverize the surface layers. As this agelong process continues, so a finer and finer grade of dust is produced, until at last it begins to flow like a liquid and accumulates at the bottom of the crater. In almost all respects, indeed, it is a liquid: it is so incredibly fine that if collected in a bucket, it will slop around like a rather mobile oil. At night one can watch convection currents circulating in it, as the upper layers cool and descend, and the warmer dust at the bottom rises to the top. This effect makes dust bowls easy to locate, since infra-red detectors can “see” their abnormal heat radiation at distances of several kilometers. However, during the daytime this method is useless owing to the masking effect of the sun.