The Sunborn

by Gregory Benford

Julia suppressed a smile. The whole nuclear rocket program had emerged from military, commercial, and exploratory arms. The Mars Prize itself had been the first step toward true international cooperation, and it had drawn two entries: Axelrod’s Consortium from the USA, flying in big chemical boosters, and the Euro-Chinese end run, using a nuke.

  After that, it seemed obvious that merging abilities and assets, with economies of scale, could make space a far easier enterprise. Ultimately that cooperation had formed the International Space Agency. Axel-rod’s can-do personality had driven much of it. Julia spoke with him nearly every week, still, but her memories of him were over two decades old now and fading. But she was sure that the man would never do anything that did not hold at least the promise of profit.

  “You forget the ice asteroids,” Viktor said.

  Praknor just looked perplexed, so he went on. “Inner solar system was dried out by early, hot sun—the T Tauri stage, is called. Sun’s light pressure blew lots of light elements out, so the gas giants are all beyond the asteroids—and even ’roids are dry. To develop inner solar system, need light elements—water, carbon dioxide, methane. There are whole chunks of that orbiting out beyond Neptune—the Pluto expedition found lots. Tested a few. Axelrod wants to move some in, far in—to here—so Consortium can use.”

  Praknor snorted with derision. “Move asteroids? Wouldn’t it take huge energies?”

  “No, little needed. ’Roids out there move with orbital velocities of maybe one, two kilometers per second. Slow. Take that away, they fall straight in toward sun.”

  “But even a small change, for such a huge mass—”

  “Use nuke reactor. Melt some of ice, heat, blow it out back, makes rocket. Use the ’roid’s own ice to move it. Cheap.”

  Praknor blinked, her mouth pursed, and then she stiffened. “That’s what the board thinks?”

  “Axelrod says so in his letter,” Julia added. “Me, I think he wants to get all the help he can for the Pluto expedition. After all, it’s getting plenty of media attention—distracting people from what we’re doing here.”

  Praknor said slowly, “He wants to get back in the game.”

  Julia could tell by the subtle sag of Praknor’s shoulders that she was accepting defeat. “If he can supply water to people in the asteroid belt between Mars and Jupiter, he can capture all the mining industry. There are more metals available in the belt than in the outer crust of the Earth.”

  “But is more,” Viktor said, eyes crinkling.

  “What?” Praknor was guarded, already hammered heavily by this torrent of news.

  “On Pluto expedition is his daughter. And they are in deep trouble.”

  Before falling asleep, cuddling close, Julia said thoughtfully, “Didn’t these last few days seem, well, a bit odd?”

  “How you mean?” Viktor was sleepy.

  “First we get Praknor, who made a mess of dealing with us. Got our backs up.”

  “Axelrod is not diplomat.”

  “No, he’s an order of magnitude better than mere diplomats. He’s a conniver.”

  “How you mean?” Viktor turned off his light and got his skeptical look on his face. She knew that he would listen for maybe a minute, then close his eyes and drift off to sleep. Very efficient.

  “Praknor pushes us all out of shape by threatening to ship us back to the moon. She believes it, too, and is the most abrasive person I’ve ever seen sent out here.”

  “Um.” He did not open his eyes, but he said slowly, “So we think this is first of new breed.”

  “And she can point at the big nuke, due in soon.”

  “Last train out of Dodge.”

  “Huh?”

  “I been watching movies. Westerns.”

  “Oh. Then Axelrod slips in this fast sail message, absolutely authentic, in his own hand.”

  “Personal touch.”

  “Good cop, bad cop.”

  Viktor chuckled. “Praknor, very bad cop. Good cop saves us from a routine life on moon. Holds out Pluto, where the action is right now. The nuke is already partway there, see? Energetically Mars is third of the way to Pluto.”

  She ran her hands over his back. “I love it when you talk technical.”

  “I know this.”

  She made a rude noise. “So we’re to be part of a grand expedition, helping out his own daughter—and the Consortium can play it as a rescue plus science.”

  “Sells well.”

  “You got it. Great story, featuring our famous, fave heroes from the Mars Race.”

  “Is what Axelrod intended all along. Moon was phony choice.”

  She slapped his ass cheerfully. “And now we’re glad to grab the chance! A month ago I’d have resisted leaving Mars at all.”

  “Now we are ready.”

  “Yes, we are.”

  “Axelrod smart guy.”

  Julia nudged him. “Plausible, right?”

  “Does not matter.”

  “What? Why?”

  “Because he could just order us to. But this way we’re enthusiastic. Much better to have employees who want to do the work, da?”

  She felt offended. “We’re not employees!”

  “To Consortium we are.” He rolled over and put both arms around her. “Let them play their manager games. We have the fun. Is all that matters.”

  PART II

  THE FAR DARK

  Immensity is its own justification.

  —William Rotsler

  1.

  THE ZAND

  LIGHT—PALE, BLUE COLD, little more than starshine—crept over the gray ice plains. Dancing blue and green auroral sheets shimmered in the deep blackness above. On the dayside skyline a turbid yellow stain swelled at the hard brim of the world. Then a sudden blinding-bright point threw stretched shadows across the hummocked land. The seventy-seven hours’ night was over.

  Sunlight, waxing yet still wan, laid siege to a rampart of spiky white needles. Temperatures edged up from the night’s 96 degrees Absolute that made everything here rock-solid. Even the methane ice hills loomed like rumpled blue steel.

  But the coming of the sun—now a pinpoint only as bright as a streetlight a block away—changed the landscape. Methane needles caught the sunglow, and their sharp crystalline spearpoints curled, sagged, slumped. Gray vapor rose to meet the tepid dawn. It met even colder, drier air from Darkside that came sliding in on a rushing wind.

  Methane rain fell in wobbly dollops, spattering on black ice. The zand awoke.

  It peered out at the slow awakening of a slumbering land. Its body stirred. These bleak days were not remotely like the warm breath of summer, now long lost. Centuries would elapse before Pluto again saw methane ice sublime into its pink haze. The grinning crescent of Charon above loomed large but was still too small to hold its gases. The eons had stripped Charon of its methane, leaving bare, rock-solid water ice. During the richly remembered summer Charon had grown a pearly vapor tail like a comet, while still stolidly performing its gravid waltz with Pluto. Now its vast, pocked plains yawned above as each world rotated with the other, face-to-face. Like dancers forever doomed to the same pace, the ice world’s cycle repeated every 6.4 days.

  Surface relays kindled by the sun sent crisp neural discharges coursing through the zand’s body. The spherical shell that had sealed it from the long night split and retraced. Brittle rods clacked, withdrawing inside, finding fresh socketings in an internal skeleton. Pulpy organs sluggishly awoke. In such deep cold, only organic solvents could ooze to a slow, throbbing pulse.

  The zand turned its ice-glazed lenses directly toward the hard point of radiance. This prickly stimulus was just barely enough. Radiance. Aided by energy hoarded through the bitter night, thick motor rings of muscle along the zand’s daytime body began to pulse. The great beast moved. Sluggishly.

  Just before easing into sleep the night before, the zand had marked an outcrop of foodrock and carefully covered it with snow. Now the ever-thickening rain beat upon the cache. The zand sp
lashed through rivulets to the top of the knoll, fighting the humming wind that blew toward the dawn. As it struggled uphill, the chilly breeze seemed to be always against it.

  Finally the top. Stiffly the zand extruded its blower and drove the rest of the damp, melting snow off the outcrop.

  Nothing. Something had harvested this lode in the long night.

  Darksiders. One had gotten by their fragile lines. Perhaps to do damage elsewhere?

  Despair swept through it. Darksiders could slip through because the zand were all weak, terribly weak.

  Then it put all thought aside and rested. Dizziness spun through the long body. Each move sapped its precious stores, and it knew now that it had used too much from its small stock of energy. This was going to be a very near thing.

  It mustered more chemical energies within itself and went on. Its legs creaked and trembled.

  Desperately it turned its head to scan the area for food. From this hummock it could see farther. The world’s gentle curve was obvious from this height. If it found nothing, it would not live out another day.

  There! On the horizon black spore cases popped open. Nitrogen, compressed and pent up all night, blew out the tiny cells locked inside. The plant’s shell was as hard as the zand’s own night armor, but it was designed to rupture at dawn.

  Most of the hard seeds fell on barren ground and died. A few spun in long arcs toward the zand. This landed them at the base of the knoll. They instantly burrowed in. Ravenously, ecstatically, they ate. From their positive poles hissed the buoyant lifegas the zand so badly needed. Within their bodies the powerful solvent released by their banqueting reacted with their cell-stuff, yielding other, heavier gases. They split, dividing to multiply. Wriggling, they squirmed deep into the porous foodrock and spread across the rumpled face, their surging mass smothering it in a brown carpet.

  The zand edged closer, waited for the right moment—and struck. Greedily it sucked in deep savory drafts of the zesty life-giving gases they gave forth. The brown mat curdled and died.

  The zand’s sick weakness vanished. The smoldering furnace of metabolism now ignited, and its fires sent waves of strength surging along its entire body.

  For the first time since waking, the zand reared fully upright. Its spindly arms shook defiantly at the cold sky. Its chilled mind now fully unlocked. Loudly it trumpeted a hymn of praise to Lightgiver. That majestic Source of all life now floated entirely clear of the curved horizon, still shrouded in rising, swirling blue-white vapors and the driving, big-dropped rain.

  Something fluttered out of the cloaking mists. A flapper, it must be, riding the turbulent mist currents toward the outcrop to steal from the dawn’s wealth. The zand tensed to fight.

  But it struck the ice, smacking and rolling. The big dark mass came thumping and tumbling to rest at the edge of the foodrock, sending cold steam purling up from where it lay.

  Dead? More important—new. Strange. Round like Lightgiver, or like the zand itself at night, but smooth, shiny, hot. It even melted the rock-hard ice beneath it. In its polished surface the zand saw itself, grotesquely distorted.

  Heat was wealth. The zand hungrily reversed its blower-organ and vacuumed the thing into its forward orifice.

  Then came the first shock. This thing was heavy, throbbing, worse than a large flapper. Dull pain throbbed through the zand’s alimentary tract. Its first impulse was to spew the offensive lump forth. But the zand had not survived countless nights to greet Lightgiver by merely obeying its impulses. It hunched closer to the outcrop and scooped up a generous helping of spicy mites. At once their furious body chemistry gave aid to its own. A fuming corrosive kindled in their first digestive stage. This syrup bit into the strange sphere. The shiny skin fumed and bubbled.

  The zand’s inward discomfort transmuted into a heady glow of well-being. Strange, vibrant tastes rippled through its body. Nothing except Self-merge had ever given it such joy.

  It verged on delirium. Dimly, through a curtain of pleasure, it felt the rain of wobbly drops ease, mists lifting to unveil the hard, hot glory of Lightgiver’s face. Ruby melt fluid trickled from warming rocks. Digestion simmering, the zand felt flooded as never before with power and hope. Turning its back to the wind, it sloshed away from the knoll where it had very nearly died.

  Without a pause it dove into the dawn sea. Waves broke across it, bringing warmth. The sky brimmed with Lightgiver’s promise. It was at peace.

  It wondered where the shiny sphere had come from. Over the horizon, toward Lightgiver. An excellent puzzle to solve on such a fine day. It moved steadily, legs clacking, storing lifegas and burngas from the brimming fresh air. Radiance filled it.

  Breathing in deeply, it broadcast a rejoicing morning song.

  2.

  CALLING HOME

  SHANNA PUT ON the last movement of Beethoven’s Fifth and turned up the gain.

  Ludwig von Cornball, they had called him back at Moonbase One. Hipitude: post-postmodern irony. All because she played ol’ Ludwig so much—but who was more appropriate? What spirit better expressed the grandeur of an expedition to the edge of the solar system?

  She could well visualize Dr. Jensen tut-tutting at this latest display of childish dramatization. But Moonbase and Jensen—and more to the point, her father, the Great Axelrod—were electromagnetically five hours and twenty minutes away. Physically, even at high nuclear impulse, they were well more than a year away.

  For now, within the survival limits set by her spacecraft—Proserpina, yes, hers, even if she did have to pretend to egalitarian methods with the crew, her crew—she could do what she damn well pleased. With a happy sigh she relaxed into her hammock and gave herself up to the symphony’s triumphant chords.

  Still, indeed, she was on watch.

  With a foot she pushed off against a bulkhead and swung slowly in the ship’s light centrifugal gravity, eyes on the wall screen. Ludwig had never imagined a place like this, yet the music fit.

  Pluto was dim but grayly grand—lightly banded in pale pewter and salmon red, save where Charon cast its huge gloomy shadow. Massive ice sheets spread like pearly blankets from both poles. Ridges ribbed the frozen methane ranges. The equatorial land was a flinty, scarred ribbon, rock hemmed in by the oppressive ice. The planet turned almost imperceptibly, a major ridgeline just coming into view at the dawn line.

  Observers on Earth had thought Pluto, Charon, and the sun could only line up for an eclipse every 124 years—but in 2029, to the utter surprise of Earthside astronomers, both the satellite’s orbit and the planet’s axis had begun to drift. By the time Shanna’s mission launched in 2044, Charon was eclipsing the sun regularly each Plutonian day. Axes were tilting. Whole worlds were spinning up.

  Strange, but just the beginning, thought Shanna. The game’s afoot, Watson.

  Even from Earthside satellite observatories—forty Astronomical Units away—it was obvious that Pluto was warming. The spectral bands of its nitrogen atmosphere showed steadily rising temperatures, working up toward the heady heights topping 100 degrees above Absolute Zero. (Or more than 300 degrees Fahrenheit below zero, for the American audience; when would they go metric?) All this, despite Pluto’s steady retreat from the sun as it followed its 273-year, highly elliptical orbit. Into the far dark.

  Nobody had expected the warmth. Or the steady intrusion of the interstellar gale, pushing in on the sun’s own solar wind. That steady pressure was simply the plasma and gas that coasted between the suns, pressing against the prow of the sun’s own wind, as the sun swept through the galaxy in its own orbit, about the galactic center. What the astrophysicists called the pause point—which meant where the solar wind met its equal and fought endlessly—that point was edging in, steadily. Against an unseen pressure from beyond the stars.

  Why was it coming in? How? Nobody knew.

  And how typical of Pluto and its moon that they should thus confound Earth’s experts—who had warned her that this remote, small, cold world would be dull, the mysteries
arcane. Yeah, yeah, yeah: gray, dim, frigid. (Hadn’t she had a boyfriend say that once? And he’d been so wrong…)

  They—all the astrobio experts, and the outright astronomers, too—hadn’t seen any of the mystery here, the magic. Fine, let ’em stay home.

  Shanna wondered about the glorious filmy auroras. They alone were worth the trip, even though a beetle-browed congressperson from one of the finance committees would hardly have agreed.

  Had the great, luminous auroras been here before…well, before what? Nobody had a clue what was driving the warming. Or the steadily incoming pressure.

  Could the auroras be involved? They were much like Earth’s—sheets of excited molecules radiating, stirred by the incoming sleet of solar wind particles. Rut these danced far faster, rippling with vibrant colors, like flapping flags.

  She let the view absorb her for a last few moments. Each of her fellow crew—the two Kares, Chow-Lin, and Ukizi—had a specialist’s fascination in the frigid vistas. But they were asleep, and she had a whole planet to herself.

  She was not the theoretician of the crew at all—rather, she was mission biologist/medical, a marginal pilot…and now captain. The physicist who had been captain, Ferrari, died in a freak accident while working aft near the combustion zone, with the robots who tended the nuclear engines. They’d lost three ’bots, too, which were harder to get along without than Ferrari, in her opinion, though she kept quiet on that score.

  A disaster, yes—but despite Earthside’s hesitations, she had assumed command, leaving to Jordin Kare the primary piloting jobs. It had been touch and go there for a week, as they drove outward at a steady 0.3 g acceleration. (Hey, maybe they’d pick up a little Mars Effect in the bargain.) That was a huge rate; if they’d had the fuel to keep to it for the whole outbound trajectory, they’d have gotten here in three months. As it was, the mission had very nearly been called back when Ferrari died. It had taken all the sweet-talking she could muster to deal with both crew and Earthside, plus arm-twisting by good old Dad. Never forget that, she thought ruefully.