One world did swim by to become bright enough briefly to rival the still-distant sun. They all crowded to the windows to see. The planet remained a mere point of light to an unaided eye, but they used the ship’s enhancement features to see better.
It was a giant, a ball of murky gas that swathed a rocky core larger than Earth. The planet’s color was a dull, washed-out yellow-brown, but you could see streaks and whorls in the cloud tops, sluggish storms curdling that thick blanket of air. Reath pointed out moons, balls of rock and ice that were minor worlds in their own right. And, strangest of all, the planet was circled by a ring, a band of light centered on the planet.
This planet, Reath said, was called Saturn. It was the system’s largest surviving gas giant; there had been one larger, but that had long been destroyed, and was anyhow hidden on the far side of the sun. Saturn had once been central in the planning for the defense of Earth itself. “It’s a fortress,” Reath said, “a vast natural fortress circling on the boundary of the inner system.”
Alia asked, “And what about the rings?”
“Orbital weapons systems, very ancient. They break down, collide, smash each other up. In time their fragments have been shepherded into those ring systems by the perturbation of the moons’ gravity. It’s odd,” he said. “Once Saturn was one of Sol system’s most spectacular sights, for it had a natural ring system — fragments of water ice from a shattered moon. When mankind came here, bringing war, those rings didn’t last long. But now Saturn’s rings have been reborn in these bits of smashed-up weaponry.”
On the planet itself, huge machines of war had been constructed beneath the cover of the eternal clouds. But the war had never come here; those immense machines had never been activated.
“But the machines are still waiting for the call to arms,” Reath said.
Bale said, “I wonder if they will know who to fight for, after all this time. Would they recognize us as the heirs of their builders?”
None of them, not spindly Reath or the squat Campocs or furry, long-limbed Alia and Drea had an answer. Saturn swam away into the dark.
It was half a million years since mankind had first ventured to the stars. For much of that time humanity had been locked in war — and although in the end a Galaxy had been won, it had always been Sol system, even Earth itself, that had been the principal mine for the resources for that war. So the system was left depleted.
Once, between Jupiter and the inner rocky worlds, there had been a rich asteroid belt: now it was impoverished, mined out, and scattered. The iron of the innermost world, Sol I, called Mercury, had been dug out and shipped away for so long that the little world had been left misshapen by quarries and pits. Earth’s two neighbors, Sol II and IV — Venus and Mars — had been used up, too. Mars had been stripped of what volatiles it had retained from its chill birth, and even Venus’s thick air had been transformed to carbon polymers and removed. Now, abandoned, both worlds looked remarkably similar, two balls of rust-red dust, naked save for only a thin layer of air, and with no signs of life save the abandoned cities of a departed mankind. It was a strange thought, Alia reflected, that in a mere half-million years after the humans arrived, all these worlds had suffered a greater transformation than any in the vast ages since their births.
At last the ship made its final approach to Sol III: Earth.
Even from afar the planet didn’t look quite as it did in Poole’s time. The planet’s crisp horizon was blurred by a deep, structured layer of silvery mist: in this age, Earth was surrounded by a cloud of life.
The ship cut through this community. Alia watched, bemused, as translucent animals, all amorphous bodies and clinging tentacles, attached themselves to the ship, spraying acid to get at whatever lay inside. The ship was forced to charge its hull to repel these swarming, vacuum-hardened creatures.
This unlikely community was an unintended consequence of mankind’s long colonization of near-Earth space. Once, many engineering structures had lifted up out of Earth’s atmosphere to provide access to space. There had even been a bridge that had spanned many times Earth’s own diameter to reach to its Moon — but the Moon itself was lost now. All those mighty engineering projects had long since fallen into ruin, but they had lasted long enough to provide a route for Earth’s tenacious life-forms to clamber out of the atmosphere and at last to leak out into space, where, hardened and adapted, their remote descendants still remained.
At last the ship descended toward the planet itself.
The world that came spinning up out of the dark was still recognizably Earth. Alia could even name the continents, so familiar from Poole’s maps. She knew that the continents were rafts of rock that slid around the surface, but even half a million years was but a moment in the long afternoon of Earth’s geology, and the essential configuration was unchanged.
The continents’ shapes had subtly altered, though, she saw. The land had pushed out to sea, and where the great rivers drained into the oceans, fat deltas crowded into the water. The oceans, steel gray, had receded since Poole’s time. Not only that, there was no trace of ice, at either North or South poles; in the north there was a cloud-strewn ocean, and the southern continent, Antarctica, was bare green and gray. A good fraction of Earth’s water must have been lost altogether.
In the temperate regions most of the lowland was inhabited. The ground was coated by a silver-gray broken by splashes of vivid green. The habitation was so widespread, crowding from mountain peaks to river valleys, it was hard to distinguish individual cities or communities. But in the sprawl of urbanization there were distinctive patterns — circles, some of them huge, which shaped the development around and within their arcs. Roads like shining threads cut across the plains of habitation, linking the circular forms, and Alia could make out the sparks of flying craft.
Reath pointed to the ground. “See those circular forms? In the time of the Coalition, they built all their cities that way, low domes on circular foundations. Conurbations, they called them.”
“They were copying alien architecture,” Drea said. “And they gave their cities numbers, not names. They didn’t want anybody to forget that Earth had once been occupied.” It was a familiar story, a legend told to children across the Galaxy.
When the Coalition fell the great domes had been abandoned, mined for materials, left to rot. But the first post-Coalition cultures had established their towns and cities inside the old circular foundations. That was half a million years ago, and since then Earth had hosted a thousand cultures, and had fought numberless wars; the people thronging its streets probably weren’t even the same species, strictly speaking, as the folk who built the Coalition. But still the circular patterns persisted. On Earth, Alia thought, everything was ancient, and everywhere reefs of a very deep antiquity pushed through the layers of the present.
The only exception to the general pattern of habitation and cultivation was South America. On its descent toward its landing site in Europe, Reath’s shuttle cut south of the equator and swam across the heart of this continent. The land was covered from mountain peak to shore by a bubbling carpet of crimson-red; only the bright gray stripes of great rivers cut through the dense blanket.
Alia pointed this out to Reath. “It looks like vegetation,” she said. “Like wild vegetation. But there’s no green. ”
Reath shrugged. “It probably isn’t native. Why should it be? Earth is the center of a Galactic culture. For half a million years life-forms from all across the Galaxy have been brought here, by design or otherwise. Some of them found ways to survive.”