The Sunborn

by Gregory Benford

  By now she knew better. Not flesh, but once living—if machines could truly live, even very smart machines like the Darksiders. But emotion yields slowly to reason; she still thought of the Darksiders as autonomous intelligences. Even after their captive onboard turned out to be a robot of sorts, able to carry out instructions well but incapable of original action.

  She inched her crawler forward. Working in a comfy work pod, directing the crawler with telepresence gloves, she had to be careful not to alarm her prey. Ahead, the gunmetal-blue, oblong Darksider didn’t seem to notice. Maybe it was recovering from its landing. Or playing possum.

  Remember, you’re the new kid out here. Maybe we don’t know all that lurks in these shadows. You might look like an intriguing new kind of lunch.

  She moved her hands in their command gloves and made the crawler grind forward another meter, crunching ice. Her low crawler was creeping on treads up to the Darksider at a shadowy angle. In the incredible cold here slow was always a good idea. Parts froze up without notice. Circuitry went dead, and even an emergency warm-up couldn’t revive it. When the crawler stopped or pivoted, she sent a surge of electricity through it just to keep it warm. Moving here had an ominous, ponderous feel that got on her nerves.

  Another sluggish move, then a wait. The Darksider didn’t seem to mind.

  Scavenging for Darksider remains had turned out to be easier than skystone hunting. Earthside wanted more parts, to better understand the different Darksider designs. Skystones, a rather poetic name for the rain of incoming meteors. She had come to like the whispery acoustic language of the zand, and their name fit, a combination of “zany” and “grand.” They were both, speaking in long, wispy chords that skated great distances through the thin nitrogen-methane air. Chilled words, pealing out with a rolling rhythm that reminded her of whale song. But unlike the whales, this time she caught what the zand were saying.

  This was yet another wonder, but one human-made. Wiseguy had picked “skystones” as more expressive than English’s “meteors.” And indeed, the incoming rocks did not flare in the chilly “air” here, just slammed into the ice, carrying fresh Darksiders—from where? Their captive Darksider would not say; perhaps its narrow intelligence did not know.

  “Got the target?” Jordin asked over comm.

  “Dead on. Big one, looks like parabolic antennas sticking out of the carapace.”

  “Let me know, huh?” His tone was edgy. “I’m on this watch, too, y’know? It’s not nice to just say nothing, leave me hanging here.”

  “I’ll try being nicer if you’ll try being smarter.”

  “Hey, just because I screwed up capturing that pair of Darksiders—”

  “Okay, okay.” She should be keeping peace, but he was sometimes irksome. And he had messed up the last telepresence run. “I’m just watching it for now.”

  “Oh. I’ll get on the spectral scan.”

  “Actually I thought you were napping.”

  In his lately familiar miffed tone he shot back, “I’m checking your every step.”

  “Don’t need a babysitter, y’know,” she said. “Catch up on your sleep.”

  “That an order, Captain?” Jordin said stiffly, with a subtone of derision to boot.

  Yep, I’m still captain, and that’s what’s bugging him. “Sure. Nod off all you want. Earthside won’t know.”

  “Might just do that.”

  Actually he was right. They had all been working so hard, for so long, that four days ago Earthside told her to institute mandatory days off. Nobody was going to honor that, she could tell right now. They all loved this vast, strange problem set before them. The shadowy mysteries kept them going.

  Jordin signed off, though it would be just like him to keep his headphones on as he slept, just in case. She couldn’t seem to strike the right notes with him these days. She knew she was getting a bit snappish, but no wonder. The approach of High Flyer was stirring anxieties old and new. And this long mission was rubbing personalities against each other. Plus some unusual stresses…

  Dear old Dad had come through for her, right—but as Axelrod the Great, wielding his legendary deal-making magic. They’d had a lot of conversations the last few days—one-way at a time, of course, given the huge distances.

  “I’m gonna have to burn a lot of chits to keep you as captain,” Axelrod’s concerned face had said. “It’s going to take promises, and I’ll have to make good on them. Remember what we talked about before—plenty of people want Darksider tech. They’re betting it’ll blow away any robots we’ve got here.”

  Meaning, of course, that the Consortium was betting. Even though this was an ISA mission. “Well,” she’d replied, “as captain I’m your best bet to get anything at all from this mission.”

  His answer hours later had infuriated her. “Y’know, honey, High Flyer can get us Darksiders, if necessary.”

  Lucky for tape delay; her first reaction would’ve been a disaster. Something on the lines of “The Mars Couple? Over the hill, Dad.” Finally she’d settled for “It might be tricky for the Consortium to get around ISA’s claims of first discovery. Ask your battalions of lawyers. But if I back up your claim, as the Consortium’s rep on this mission all along, it’ll be a lot easier. Daddy dear.”

  His face showed grudging admiration on the next vid. “Good point; so we have a deal. Oh, and I’m getting interest in having some small zand back here, if the exobiologists can figure out how to manage it. We want them alive, not stuffed. Possible? Nobody knows. I’ll have more details later.”

  What a Victorian he’d have made! Zand aren’t European, white, or Christian, ergo they have no rights. Without seeming to disagree, she’d sent, fingers crossed behind her back, “As they’re sentient, they’ll have to agree to go, Daddy dear.” Might as well keep the edge in the dialogue.

  She was still waiting for his reply.

  A ping from the instrument board snapped her back to the present.

  Hey, concentrate.

  One more meter… Out of shadow now. Closer…

  Her boards reported weak microwave emissions from the prey, but it remained stark and silent on the snow. But no, not a corpse, she reminded herself. The latest arrival, radar tracked from far beyond Pluto. Better to grab than pieces. Her hands moved in air like a pianist’s.

  Move. Close with it.

  The crawler probe clanked forward and stuck out spindly grapples. Grasped. Gotcha.

  She reeled in her catch like a fish—back to the waiting lift vehicle, in slow, deliberate moves. While the probe and its burden were still lifting off for the mother ship, Proserpina, the DIS computer ship-mind whirred through a preliminary analysis. Shanna watched the silvery ship rising toward them over the curve of the planet and felt sharp anticipation.

  The probe made it back without incident. The crew did maintenance, getting ready to leave orbit. Shanna waited for her chance to see the new catch up close.

  The new Darksider was nasty, which to a biologist meant interesting. Those fierce-looking claws—tantalum carbide, hard and tough even in supercold. The structural shell—aluminum/titanium alloy. (Magnification, please.) Those looked like mechanical relays of some sort, and they were made of solid mercury? Sure; at these temperatures, why not?

  But what was the purpose of those patterns of rare earths? And those curves, seen in projection, looked almost like a conventionalized helix—Oh.

  Shanna spoke into her recorder. “Hypothesis: these devices, whatever they are, contain a genetic model. Yeah! A helix, too, recalling DNA. A model of what? Of the ‘ideal’ zand, from a Darksider’s point of view?” Her mind made a large leap. “We already know that these infalls came periodically, from dating the ones we found, centuries old. Chow-Lin did it using isotopes, I dunno how. So—when Pluto arcs out along its steeply elliptical orbit, something hammers it with Darksiders. Been doing it for at least three planetary orbits—that’s nearly a thousand years! Darksiders scan the zands. Those that don’t measure up they squish.
”

  Guided evolution? Part of the grand experiment on Pluto?

  The probe clunked into its housing; she heard it ring. A conveyor rattled, taking its burden down to Proserpina’s low-temperature laboratory. Time to get to work.

  Appropriate background? Something romantic but reflective, she decided; Schumann’s Konzerstück.

  Supported by mellow French horns, the piano chords rolled out while DIS, now in direct physical contact with the specimen, shifted into high speed. She fancied she could hear it hum.

  Views of their catch filled the curved screens around her. Well, well—this beast hadn’t been bent from sheet metal in a machine shop, that was sure. Coldformed, one molecular layer at a time, grown as crystals were. From the Oort clouders’ massive perspective, she guessed, a delicate job of microengineering.

  And the chilling thought came: from that same perspective, the injection of those “tools” into the zand culture would be no more a “raid” than the injection of antibiotics into a human bloodstream.

  The thing was not dead, instruments said. Maybe shut down by itself, to save power. Or maybe orders from some mysterious Other. With care, and with the help of DIS, she could probably feed a trickle of tailored DC into its superconducting circuitry and bring it back to life. Make it move, clash those jagged claws, jump up and down. (Boogie! she almost heard Grandma say. Her father, alas, never got that loose.) Possibly attract its makers’ attention that way?

  If one of her own hemoglobin molecules tried to get her attention, would she notice? That was the relative scale between herself and the hypothetical somber dwellers in the Oort cloud, in the far dark beyond the warm worlds. Yet they had made the rickety zand biosphere, whoever or whatever they were.

  They had plenty of room, too. Where the sun’s gravitational grip slackened, countless icy islands swung, taking centuries to complete a single orbit around the dim home star. That archipelago stretched halfway to the next gleaming stars. As infinities went, it would do quite nicely.

  They had come seeking the root of a mystery, never anticipating that the answer would be so vast and startling. At the end of the twencen, Pluto’s atmosphere had seemed to start cooling off, as the planet arced outward on its slanting ellipse. Atmospheric specialists predicted it would freeze out somewhere before 2020.

  Only it hadn’t. Instead, even as the first probe sped outward, the thin film of chilly nitrogen and methane cloaking Pluto began to warm. Other compounds began spiking their spectral signatures up on the most sensitive Earthbound detectors: water vapor, carbon dioxide, even nitrogen wedded to oxygens.

  And as the mission had prepared, a further, ominous puzzle arose: the solar system’s bow shock was moving. This “pause point” is the working front where the sun’s outward wind of particles meets the interstellar plasma. This forms a surface much like the curve made by a ship powering across a lake, seen from above. Before, the nearest this bow shock had gotten to the sun was about one hundred astronomical units, a full hundred times farther than the Earth-sun distance. But now that fluttery front lay only a few AU beyond Pluto, now just a tad beyond 40 AU from the sun.

  If the solar wind let that wall of molecular hydrogen behind the shock intrude into the inner solar system, Earth could be destroyed. Even approaching partway in, say into Saturn, would be very dangerous. That seemed unlikely to the specialists, but without an explanation of what was happening beyond Pluto, few found that comforting.

  At first Shanna had thought the bow shock issue was pretty nebulous—after all, it was about thin gases, right?—and had to keep reminding herself of an old diagram from the early space program. It showed the solar system plowing through the interstellar spaces, pushing gas and plasma before it like a snowplow. If a voyage from the sun to the nearest star were like a marathon, in reaching Pluto the runner would have gone only fifteen feet. Both Voyagers and Pioneer had passed into the outer realm, genuine interstellar space. But if the solar snowplow weakened—or the pressure of the interstellar gas increased—the boundary would intrude farther in, brushing the planets. One swipe with molecular hydrogen and Earth’s oxygen would combine, making water and a lot of energy. The biosphere would get hot and breathless within days. Even little trickles of hydrogen could hurt a lot.

  She often gazed at the old NASA sketch—from back before it joined ISA—of the region they were now exploring. All very clean and scientific. No mention of lethal weather.

  And now Pluto held life. Not just chilly slime molds and small crawly creatures, but a few species in all, crowned by the self-aware zand. And her bet was that these in turn were being altered by the sky-stones that fed them…and the Darksiders that bled them.

  Earthside scientists now bet that Pluto was driven by energies somehow imported from where the bow shock roiled and frothed in plasma arcs bigger than planets.

  DIS said, “Transmission due.”

  “Ummm.” She owed it to Earthside, after the grief she’d given them, to at least keep punctually to their radio schedules. A fundamental rule of missions: there was always some damn thing interrupting. She told DIS to start trying revival methods on the newly captured machine. It had gone silent shortly after they began talking to it. Chow-Lin and Jordin had spent weeks trying to get the first Darksider—their hitchhiker—to respond, and concluded that it had been ordered (by what?) to shut down. Now she wondered if anything would work on the new one.

  She switched on audio and visual and tried to relax in her obliging smart chair. Deep breath—

  “This is Astronaut Shanna Axelrod, aboard Proserpina, in Pluto orbit.” It still gave her a charge to be able to say that. (And Grandma would have warned her not to get so swellheaded.) They would edit and polish for the whole brimming Earthside audience, of course, as now required by full-disclosure laws. She hoped no laser-link pirates had caught her latest reports. They had started to swoop into the beam and carried off choice nuggets, decrypting them and bootlegging them in time to compete with the cleaned version. Embarrassments galore, unless she kept close to the vest. But who could, all the time?

  In the background Schumann sang, and DIS clucked and ruminated, while she talked. Arpeggios rose from sonorous lower octaves. The longer this mission went on, the more she needed music’s sense of human connection, of grand prospects. For that, the romantics were better than even Bach, for her.

  “Not much progress on the Darksiders. The ones in the cold lab talk for a bit, then shut down. DIS is working on it, but my guess is they’re unable to run very long without instructions—from where, though?”

  She felt a fluttery twinge of unease. Minimal speculation, ISA had ordered. Earthside thought she was moving too fast. She wanted to know—and it was their lives on the line out here, right? Easy, now—keep your tones proper and level. Or should she record these little reports and have DIS take out the stress-diagnostic frequencies? Yep, she should consider that. Tomorrow.

  “So, zilch. The local Pluto life-forms, the zand especially, I’d love to take the time to study them. But they’re maybe a sideshow, Jordin and I—and the rest of the crew—think. You’re just going to have to rely on our judgment.”

  She took a deep breath. Even after years of talking into silence, knowing that her message would take hours to get to its listeners made her uneasy. Humans need conversation, not oration.

  Then there was the psychers’ explanation. Reminding her of how far away they were from help? With one exception, yes.

  “And, speaking of the zand, I’ve had some second thoughts on what to do about their situation. They’re on the wrong end of a predator-prey dynamic. We can help them, sure, though that goes way beyond our mission profile. And we’re using the Darksider-type strategy! Hiding from sight and occasionally sneaking a meteorite in amongst them might be as bad for them as to have Lady Bountiful descend from the clouds in full view. It could make them completely passive.”

  Amateur psychoanalysis, sure, but it made sense even for aliens. Skystones will fall when needed, ri
ght? Lightgiver will provide; they need do nothing.

  “There’s quite enough external control over their fate as it is, with even their genes—if I can use that word imprecisely—messed with by outsiders. I’d like to see the zand stand up on their own feet, even though feet are something they haven’t got.”

  Hopeless anthropomorphism: she could all but hear Dr. Jensen snap out the words. Hey, it’s a metaphor, guys.

  Avoid argument, Shanna told herself; you’re really in charge out here, calling all the shots. Captain! But get some advice first.

  “So”—pause for the beat—“I’m having DIS plot us a new course, toward High Flyer. I want to link up with them. I know, I know—Proserpina wasn’t made to go out into the comet-rich inner disk. But we’ve picked up a lot of easy water here, heating the ice. We had the lander haul some up on the return from recon descents, using our ’bots to do the grunt work. We’re fully fueled. The mysteries of Pluto can’t be solved on the planet alone, and we’ll make a powerful team out there, with High Flyer.”

  There, it’s said. Not crazy, no. Hell, Earthside sends a totally new kind of ship out to explore further and wants us to meekly head on home? As the original mission plan called for?

  The rest of her crew agreed, of course, but not strongly, and it was my decision, damn it! Mine alone. Captain.

  Proserpina’s pokey fission nuke drive could only make it far enough to nip at the fusion-burn heels of High Flyer. She made herself take a long breath. We can stay in the game. “I want you to consider this as an add-on to our mission. Also backup for High Flyer. We—”

  Clanging. Loud, rasping alarms.

  Shanna leaped from the immersion pod, heading for the pilot’s chair. “All hands up!” she sent on comm. A whole row of instrument lights winked red. The hull was overheating.

  But how? Panic flailed her. Heating from atmospheric friction? Maybe—were they falling out of orbit into atmosphere?

  But, no—the holoscreen image of the planet and its satellite showed Proserpina precisely on its looping curve, where it should be. What could be heating the hull and blasting salvos of static into her music deck? Reflexively she shut it off.