Arthur Clarke - Earthlight

“The only thing that worries me now,” he said, “is how long we may have to wait. It’s still possible that nothing will happen at all. On the other hand, if we start walking we may be caught in the open away from shelter.”

After some discussion, they decided on a compromise. They would keep their suits on, but would go back and sit in Ferdinand where at least they would be comfortable. It would take them only a few seconds to get to the trench.

There was no warning of any kind. Suddenly the gray, dusty rocks of the Sea of Rains were scorched by a light they had never known before in all their history. Wheeler’s first impression was that someone had turned a giant searchlight full upon the tractor ; then he realized that this sun-eclipsing explosion was many kilometers away. High above the horizon was a ball of violet flame, perfectly spherical, and rapidly losing brilliance as it expanded. Within seconds, it had faded to a great cloud of luminous gas. It was dropping down toward the edge of the Moon, and almost at once had sunk below the skyline like some fantastic sun.

“We were fools,” said Jamieson gravely. “That was an atomic warhead—we may be dead men already.”

“Nonsense,” retorted Wheeler, though without much confidence. “That was fifty kilometers away. The gammas would be pretty weak by the time they reached us—and these walls aren’t bad shielding.”

Jamieson did not answer; he was already on his way to the airlock. Wheeler started to follow him, then remembered that there was a radiation detector aboard and went back to collect it. Was there anything else that might be useful while he was here? On a sudden impulse, he jerked down the curtain-rod above the little alcove that concealed the lavatory, then ripped away the wall mirror over the sink.

When he joined Jamieson, who was waiting impatiently for him in the airlock, he handed over the detector, but did not bother to explain the rest of his equipment. Not until they had settled down in their trench, which they reached without further incident, did he make its purpose clear.

“If there’s one thing I hate,” he said petulantly, “it’s not being able to see what’s going on.” He started to fix the mirror to the curtain rod, using some wire from one of the pouches round his suit. After a couple of minutes’ work, he was able to hoist a crude periscope out of the hole.

“I can just see the dome,” he said with some satisfaction. “It’s quite unchanged, as far as I can tell.”

“It would be,” Jamieson replied. “They must have managed to explode that bomb somehow while it was miles away.”

“Perhaps it was only a warning shot.”

“Not likely! No one wastes plutonium for firework displays. That meant business. I wonder when the next move is going to be?”

It did not come for another five minutes. Then, almost simultaneously, three more of the dazzling atomic suns burst against the sky. They were all moving on trajectories that took them toward the dome, but long before they reached it they had dispersed into tenuous clouds of vapor.

“Rounds one and two to Earth,” muttered Wheeler. “I wonder where these missiles are coming from?”

“If any of them burst directly overhead,” said Jamieson, “we will be done for. Don’t forget that there’s no atmosphere to absorb the gammas here.”

“What does the radiation meter say?”

“Nothing much yet, but I’m worried about that first blast, when we were still in the tractor.”

Wheeler was too busily searching the sky to answer. Somewhere up there among the stars, which he could see now that he was out of the direct glare of the sun, must be the ships of the Federation, preparing for the next attack. It was not likely that the ships themselves would be visible, but he might be able to see their weapons in action.

From somewhere beyond Pico, six sheaves of flame shot up into the sky at an enormous acceleration. The dome was launching its first missiles, straight into the face of the sun. The Lethe and the Eridanus were using a trick as old as warfare itself; they were approaching from a direction in which their opponent would be partly blinded. Even radar could be distracted by the background of solar interference, and Commodore Brennan had enlisted two large sunspots as minor allies.

Within seconds, the rockets were lost in the glare. Minutes seemed to pass; then the sunlight abruptly multiplied itself a hundredfold. The folks up on Earth, thought Wheeler as he readjusted the filters of his visor, will be having a grandstand view tonight. And the atmosphere which is such a nuisance to astronomers will protect them from anything that these warheads can radiate.

There was no way to tell if the missiles had done any damage. That enormous and soundless explosion might have dissipated itself harmlessly into space. This would be a strange battle, he realized. He might never even see the Federation ships, which would almost certainly be painted as black as night to make them undetectable.

Then he saw that something was happening to the dome. It was no longer a gleaming spherical mirror reflecting only the single image of the sun. Light was splashing from it in all directions, and its brilliance was increasing second by second. From somewhere out in space, power was being poured into the fortress. That could only mean that the ships of the Federation were floating up there against the stars, beaming countless millions of kilowatts down upon the Moon. But there was still no sign of them, for there was nothing to reveal the track of the river of energy pouring invisibly through space.

The dome was now far too bright to look upon directly, and Wheeler readjusted his filters. He wondered when it was going to reply to the attack, or indeed if it could do so while it was under this bombardment. Then he saw that the hemisphere was surrounded by a waveririg corona, like some kind of brush discharge. Almost at the same moment, Jamieson’s voice rang in his ears.

“Look, Con—right overhead!”

He glanced away from the mirror and looked directly into the sky. For the first time, he saw one of the Federation ships. Though he did not know it, he was seeing the Acheron, the only spaceship ever to be built specifically for war. It was clearly visible, and seemed remarkably close. Between it and the fortress, like an impalpable shield, flared a disk of light which as he watched turned cherry-red, then blue-white, then the deadly searing violet seen only in the hottest of the stars. The shield wavered back and forth, giving the impression of being balanced by tremendous and opposing energies. As Wheeler stared, oblivious to his peril, he saw that the whole ship was surrounded by a faint halo of light, brought to incandescence only where the weapons of the fortress tore against it.

It was some time before he realized that there were two other ships in the sky, each shielded by its own flaming nimbus. Now the battle was beginning to take shape; each side had cautiously tested its defenses and its weapons, and only now had the real trial of strength begun.

The two astronomers stared in wonder at the moving fireballs of the ships. Here was something totally new—something far more important than any mere weapon. These vessels possessed a means of propulsion which must make the rocket obsolete. They could hover motionless at will, then move off in any direction at a high acceleration. They needed this mobility; the fortress, with all its fixed equipment, far outpowered them and much of their defense lay in their speed.

In utter silence, the battle was rising to its climax. Millions of years ago the molten rock had frozen to form the Sea of Rains, and now the weapons of the ships were turning it once more to lava. Out by the fortress, clouds of incandescent vapor were being blasted into the sky as the beams of the attackers spent their fury against the unprotected rocks. It was impossible to tell which side was inflicting the greater damage. Now and again a screen would flare up, as a flicker of heat passes over white-hot steel. When that happened to one of the battleships, it would move away with that incredible acceleration, and it would be several seconds before the focusing devices of the fort had located it again.