Ring xs-4

by Stephen Baxter

  Still, Louise knew it did her good to get away from the ship that had been her home, and prison, for so many centuries — and which, barring a miracle, was going to have to sustain her and her people for the rest of her life. Callisto was — had been — Jupiter’s eighth moon, one of the four big Galilean satellites. At the time of Northern’s launch Callisto had been a ball of water ice and rock, heavily cratered. Debris had been sprayed across the mysterious surface from the bright cores of the impact craters; from space, Callisto had looked like a sphere of glass peppered by gunshots. One basin — called Valhalla — had been four hundred miles across, an immense amphitheater surrounded by concentric terrace-like walls.

  Louise remembered how human cities, feeding on Callisto’s ancient water, had glinted in the shadows of Valhalla’s walls, shining like multicolored jewels.

  Well, the craters had gone now — as had Valhalla, and all the cities. Gone without trace, it seemed. Callisto had been wiped smooth, unblemished save for her own footsteps.

  During, or after, the depopulation, Callisto had been caused to melt. And, when the moon froze once more, something had been trapped in the ice…

  The pod skimmed around the smooth limb of the moon. They were heading over the moon’s north pole, and soon, Louise realized, they would be passing over the sharp terminator and into daylight.

  …Or what passed for daylight, in these straitened times, she thought.

  Beside her, Spinner fitted her faceplate over her head, leaving it open below her mouth. She peered around, through the flimsy walls of the pod. From the absent, unfocused expression in her eyes, Louise could tell she was using the plate’s enhancement and magnification features.

  “I can see moons,” Spinner said. “A sky full of moons.”

  “Nice for you,” Louise said drily. “There should be eight — there used to be eight beyond Callisto. Small, irregular: probably captured asteroids. The outer four of them were retrograde, moving backwards compared to the planet’s own rotation.”

  “I’m surprised any moons survived the destruction of the planet.”

  Louise shrugged. “The nearest of the outer moons was a hundred and fifty Jovian radii from the primary, before the planet imploded… even Callisto survived, remember, and that was a mere twenty-six radii out.” The orbits of the surviving moons had been disturbed by the Jovian event, of course; the implosion had sent them scattering with a shock of gravity waves, and now they swooped around their shattered parent along orbits of high eccentricity, like birds disturbed by earth tremors.

  Within the orbit of Callisto, nothing had survived.

  Now, as the pod passed over the pole, the Jovian ring system unfolded like a huge floor before Louise, infinite-flat and streaked with shadows.

  This new ring system, the debris of worlds, lay in what had been Jupiter’s equatorial plane — the plane once occupied by the vanished moons. Callisto still lay in the equatorial plane, patiently circling the site of the giant planet just outside the ring system, so that the disc of ring material — if it had stretched out so far — would have bisected Callisto neatly.

  The ring system didn’t terminate at a sharp inner boundary, like Saturn’s. Instead the creamy, smoothed-out material stretched inwards — this system was actually more a disc than a ring system, Louise realized slowly. As her eyes tracked in toward the center the system’s texture slowly changed — becoming more rough, Louise saw, with knots of high density locked into the churning surface, orbiting through tight circles, swirling visibly.

  The whole assemblage was stained crimson by scattered sunlight.

  The rings were almost featureless — bland, without the complex colors and braids which characterized Saturn’s system. Louise sighed. The gravitational interaction of moons had provided Saturn’s rings with their fantastic structure. The trouble was that Jupiter’s remaining moons simply weren’t up to the job of shepherding the rings. For poor, dead Jupiter, only a single dark streak marked the orbital resonance of Callisto itself.

  Now, the center of the ring-disc rose above Callisto’s sharp horizon. Louise could clearly see inhomogeneities churning around the geometric center of the disc, twisting through their crowded, tortured orbits. But the disc center itself was unspectacular — just a brighter patch, spinning with the rest of the disc. It was somehow frustrating, as if there were something missing.

  Spinner sounded disappointed. “I can’t see anything in the middle. Where the planet used to be.”

  Louise grinned. “You’d hardly expect to. A black hole with Jupiter’s mass would have a diameter of just twenty feet or so…”

  “There’s plenty to see in higher frequencies,” Mark cut in. “The X-ray, and higher…

  “Toward the heart of the system we have a true accretion disc,” he went on, “with matter being heated tremendously before falling into the black hole itself. It’s small, but there’s a lot of structure there, if you look at it in the right bands.”

  Spinner, with apparent eagerness, adjusted her plate over her face, and Mark told her how to fix the settings. Soon, Spinner’s eyes assumed that unfocused look again as they adjusted to the enhanced imagery.

  Louise left her own visor in her lap; the black hole, and its huge, milky ring, depressed her enough in visible light.

  Jupiter’s new ring system, with its bland paleness, and the jostling, crowding swirl at the center, was far from beautiful, on any wavelength. It was too obviously a place of wreckage, of destruction — a destruction which was visibly continuing, as the black hole gnawed at its accretion disc. And, to Louise’s engineer’s eye, with its empty center the system had something of an unfinished, provisional look. There was no soul to this system, she thought, no balance to the scale of the rings: by comparison, Saturn’s rings had been an adornment, a necklace of ice and rock around the throat of an already beautiful world.

  Spinner turned to her, her bespectacled eyes masked by the faceplate. “The whole thing’s like a whirlpool,” she said.

  Louise shrugged. “I suppose so. A whirlpool surrounding a hole in spacetime.”

  “A whirlpool of gas — ”

  — gas, and rock and water ice: bits of smashed-up worlds —

  Louise started to tell Spinner-of-Rope about the vanished moons of Jupiter. She remembered Io with its volcano mouths and their hundred-mile-high vents, its sulfur-stained surface and its surrounding torus of volcano-fed plasma; she remembered Io’s mineral mines, nestling in the shadow of the huge volcano Babbar Patera. She told Spinner of Ganymede: larger than Mercury, heavily cratered and geologically rich — the most stable and heavily populated of all the Jovian moons. And Europa, a ball of ice, with a bright smooth surface — constantly renewed by melting and tectonic stress — covering a liquid layer beneath. Europa had been a bright precursor of this smoothed-over corpse of Callisto, perhaps.

  Worlds, all populated — all gone.

  Louise hoped fervently that there had been time to evacuate the moons before the final disaster. If not, then — drifting through Jovian orbit among the fragments of rock and ice which comprised those rings — there would be bits of humanity: shards of shattered homes, children’s toys, corpses.

  Spinner pushed up her faceplate and rubbed her eyes. “I’d have liked to have seen Jupiter, I think, with its moons and all those cities… Perhaps Jupiter could have been saved. After all, the implosion must have taken thousands of years, you told me.”

  Louise bit back a sarcastic reply. “Yes. But picking black holes out of the heart of a gas giant was evidently a bit too difficult, even for the humans of many millennia beyond my time.”

  Jupiter had been wrecked by the actions of the Friends of Wigner.

  The Friends were human rebels from a Qax-occupied future, who had fled back in time through Michael Poole’s time-tunnel wormhole.

  The Friends had had in mind some grand, impossible scheme to alter history. Their plan had involved firing asteroid-mass black holes into Jupiter.

  The Friend
s’ project had been interrupted by the arrival of Qax warships through Poole’s wormhole — but not before the Friends had succeeded in spearing the giant planet with several of their tiny singularities.

  The pinprick singularities had looped through the thick Jovian atmosphere like deadly insects, trailing threads of plasma. When the holes met, they had whirled around each other before coalescing, their event horizons collapsing into each other in Planck timescales.

  The vibration of merging event horizons had emitted vicious pulses of gravity waves. Founts of thick, chemically complex atmosphere had been hurled out of the planet, bizarre volcanoes on a world of gas.

  The Friends’ ambitions had been far-reaching. Before the final implosion they’d meant to sculpt the huge planet with these directed gravity-wave pulses, produced by the complex interactions of their singularity bullets.

  Louise now stared morosely at the bland, displeasing disc of glowing rubble. Well, the Friends had certainly succeeded in part of their project — the reduction of Jupiter. Quite a monument to such ambition, after five million years, Louise thought: a collapsed Jovian, and a string of crushed human worlds.

  And all for what? A black hole of the wrong size…

  “It’s getting brighter over there,” Spinner said, pointing.

  Louise looked right, across Callisto. A dull, flat crimson light was spreading across the ice. The glow cast long, disproportionate shadows from the low irregularities in Callisto’s smooth surface, turning the ice plain into a complex landscape of ruby-sparkling promontories and blood-red pools of shadow.

  At the horizon, smoky tendrils of crimson gas were rising across the sky.

  “Sunrise on Callisto,” Louise said sourly. “Come on; let’s land. We don’t want to miss the full beauty of the Solar System’s one remaining wonder, do we?”

  On the surface of Callisto, standing beside Louise in her environment suit. Spinner held up her arms, framing the Sun with her outspread hands; standing there on the light-stained ice floor, with the swollen globe reflected, distorted, in her faceplate, Spinner-of-Rope looked more than ever like a child.

  Sol, looming over the horizon, was a wall of blood-red smoke. It was transparent enough to see through to the distant stars for perhaps a quarter of the disc’s radius — in fact, the material was so thin that Louise could make out the steadily deepening color of the thicker layers toward the core.

  The Sun didn’t even look like a star any more, she thought tiredly. A star was supposed to be hard, bright, hot; you weren’t supposed to be able to see through it.

  “Another astrophysicist’s dream,” Mark said drily. “You could learn more about the nature of stellar evolution just by standing there and looking, than in all the first five millennia of human astronomy.”

  “Yes. But what a price to pay.”

  Once, from Jupiter’s orbit the Main Sequence Sun would have been a point source of light — distant, hot, yellow. Now, the Sun’s arc size had to be at least twenty degrees. Its bulk covered fully a fifth of Louise’s field of view: twenty times the width of the full Moon, as seen from Earth.

  Jupiter was five AU from the Sun’s center — an AU was an astronomical unit, the radius of Earth’s orbit. For the Sun to subtend such an angle, it must be two AU across, or more.

  Two astronomical units. In exploding out to become a giant, the Sun had swallowed the Earth, and the planets within Earth’s orbit — Venus, Mercury.

  Spinner-of-Rope was studying her, concern mixing with curiosity behind those pale spectacles.

  “What are you thinking, Louise?”

  “This shouldn’t have happened for five billion more years,” Louise said. Her throat was tight, and she found it difficult to keep her voice level. “The Sun was only halfway to turnoff — halfway through its stable lifecycle, on the Main Sequence.

  “This shouldn’t have happened. Somebody did this deliberately, robbing us of our future, our worlds — damn it, this was our Sun…”

  “Louise.” Mark’s synthesized voice was brisk, urgent.

  She breathed deeply, trying to put away her anger, her resentment, to focus on the present.

  “What is it?”

  “You’d better come back to the Northern. Morrow has found something… Something in the ice. He thinks it’s a spacecraft.”

  16

  “Uvarov. Uvarov.”

  Garry Uvarov jerked awake. It was dark. He tried to open his eyes…

  As always, in that first instant of wakefulness — even after all these years — he forgot. His blindness crowded in on him, a speckled darkness across his eyes, making every new waking a savage horror.

  “Garry. Are you awake?”

  It was the solicitous voice of that fake person. Mark Bassett Friar Armonk Wu. Uvarov swung his head around, trying to locate the source of the artificial voice. It seemed to be all around him. He tried to speak; he felt his gummy mouth open with a pop, like a fish’s. “Mark Wu. Where are you, damn it?”

  “Right here. Oh.” There was a second of silence. Then: “I’m here.”

  Now the voice came from directly in front of him, from a precise, well-focused place.

  “Better,” Uvarov growled.

  “I’m sorry,” Mark said. “I hadn’t formed an image. I didn’t think — ”

  “You didn’t bother,” Uvarov snapped. “Because I can’t see you, you thought it was enough to float around me in the air like some damn spirit.”

  “I didn’t think it would be so important to you,” Mark said.

  “No,” Uvarov said. “To think of that would have been too much the human thing to do for an imprint like you, wouldn’t it?”

  “Do you need anything?” Mark asked, with strained patience. “Some food, or — ”

  “Nothing,” Uvarov snapped. “This chair takes care of it all. With me, it’s in one end and out of the other, without even having to swallow.” He stretched his lips and leered. “As you know. So why did you bother to ask after my health? Just to make me feel dependent?”

  “No.” Mark sounded cool, but more certain of himself. “I thought to ask would be the human thing to do.”

  Uvarov let himself cackle at that. “Touché.”

  “It’s just that you sleep for such a long time, Uvarov,” Mark said drily.

  “So would you, if you weren’t dead,” Uvarov said briskly.

  He could hear the rattle of his own breath, the subdued ticking of a huge old clock somewhere, here in the dining saloon of Louise’s old steam ship. Hauling this useless relic five megayears into the future had been, of course, an absurd thing to do, and it showed a fundamental weakness in the character of Louise Ye Armonk. But still, Uvarov had to admit, the textures of the old material — the painted walls, the mirrors, the polished wood of the two long tables — sounded wonderful.

  “I suppose you had a reason for waking me.”

  “Yes. The Sun maser probes — ”

  “Yes?”

  “We’re starting to get meaningful data, Uvarov.” Now Mark sounded excited, but Uvarov never let himself forget that every inflection of this AI’s voice was a mere artifice.

  Still, despite this cynical calculation, Uvarov too began to feel a distinct stirring of interest — of wonder. Meaningful data?

  The maser radiation was coming from hot-spots on the photosphere itself patches of intense maser brightness, equivalent to tens of millions of degrees of temperature, against a background cooler than the surface of the yellow Sun had once been. The convection mechanism underlying the maser flares’ coherent pathways fired the radiation pulses off tangentially to the photosphere. So the Northern had sent out small probes to skim the swollen, diffuse surface of the photosphere, sailing into the paths of the surface-grazing maser beams.

  “Tell me about the data.”

  “It’s a repeating group, Uvarov. Broadcast on maser wavelengths, from within what’s left of the Sun… Uvarov, I think it’s a signal.”

  They hadn’t learned much about the
Solar System, in the year since their clumsy, limping arrival from out of the past. So many of the worlds of man simply didn’t exist any more.

  Still, in the quiet time before the arrival of the Northern at Jupiter, Uvarov and the AI construct had performed some general surveys of the Solar System what was left of it. And they’d found a few oddities…

  There was what looked like one solid artifact — Morrow’s anomalous object buried in the ice of Callisto. And, apart from that, there were just three sources of what could be interpreted as intelligently directed signals: this maser stuff from the Sun, the fading beacon from the edge of the System, and — strangest and most intriguing of all, to Garry Uvarov — those strange pulses of gravity radiation from the direction of Sagittarius.

  Uvarov had done a little private study, on the structure of the Universe in the direction of Sagittarius. Interestingly enough, he learned, the cosmic structure called the Great Attractor was to be found there, right at the place the photino beam was pointing. The Attractor was a huge mass concentration: the source of galactic streaming, for hundreds of millions of light-years’ distance around. Could the Attractor be connected to the g-waves?

  And then there was all that strange photino activity in and around the Sun.

  The data was patchy and difficult to interpret — after all, dark matter was, almost by definition, virtually impossible to study… but there was something strange there.

  Uvarov thought he’d detected a streaming.

  There was a steady flow, of photino structures, out of the heart of the Sol giant… and on out of the Solar System. It was a beam of photinos aimed like a beacon, out of Sol — and straight toward the source of the anomalous gravity waves in Sagittarius.

  Something was happening in Sagittarius — something huge, and wonderful, and strange. And, somehow, impossibly, it was connected to whatever was taking place in the heart of the poor, suffering Sun.