The Sunborn

by Gregory Benford

  Shanna mused about the lives she had blasted to oblivion, so quick in her certainty. Had those dim mechanical forms been truly alive?

  Definitions, her grandmother once said, had to be like a fat man’s belt—big enough to cover the subject but elastic enough to allow for change. Out here life clung to the last vestiges of possible chemistry. And she was sure, now, that evolution alone could not have forged such an intricate ecology, with so few species—not even in the 4 billion years Pluto had spun.

  The topsoil samples they had brought back had yielded nothing. If Earth or even the dimmed ecology of underground Mars was any guide, life found myriad small species to kindle. Larger forms stood upon a huge, broad pyramid of microbes beneath. Bare stony soil could yield little. Yet the zand, the Darksiders—they were like cartoons of life-forms.

  Woven from what?

  Those things in the pit were not forged from nature’s relentless mill, for they did not know anger.

  They had not wreaked vengeance on her and Jordin when they had the chance. Instead, they had saved them both.

  For a moment Shanna pictured the Darksiders at the opposite extreme, as saints, but that, she knew instinctively, was also wrong.

  They were, finally, constructions. Theoretical models. More like robots than organisms, but way ahead of Proserpina’s ’bots. Not machines, perhaps, but something that stretched the definition of life and probably broke it.

  She let her intuition rummage around a bit…Yes. The Darksiders were agents of something larger, something feeling its way, something…dispassionate. But what?

  Pluto orbited in its elliptical sway at the very verge of that realm where chemical reactions could proceed sluggishly. Beyond here lay a black abyss in which the seemingly fragile bonds between molecules would not crack before the weightless hail of sunlight. They congealed in the unending cold.

  In that dark kingdom only electricity could race and flow, to bring motive meaning from the potentials and gravid capacitances, hanging in the vast vacant spaces. There, beneath distant star gleam, gossamer-thin sheets of electrons drifted silently before the subtle tugs of inductances, in vast circuits that light itself could barely span in a full day.

  She shook her head, trying to see…

  Biologists think in terms of slow, blunt chemistry. Out here there might be instead the rule of electrodynamics, proceedings only a tiny fraction slower than light. Intelligence set free from molecular torpidity could dash across immensities, unchecked by all but the gritty limits of matter’s innate resistance. There the speed of light was the natural speed of events. Of thoughts.

  Something had made use of these truths, some brooding intelligence hitherto unsuspected, though the basic laws—of thermodynamics, of electromagnetic fields—had been known to humanity since their discovery in the nineteenth century. Back then the laws had emerged among people seeking to heat and light their shadowy homes. They wanted efficiency. From such practical measures had come fundamental truths. An old term came to her: electrobiology. In the early twencen earnest physicians and greedy quacks had sold appliances that meted out small electric shocks, reputed to cure everything that ailed the human body. It hadn’t worked back then, but something way out here was blending electrodynamics and chemistry in the hard cold of Pluto.

  For some reason the forces out there had conducted an experiment on this little dab of rock and ice, blending the two sources of animation—chemistry, electricity. Frankenstein’s legacy?

  What’s more, the experiment was still young. It looked like a work unfinished, left by giants for a better day, vast and massive but incomplete.

  When would the giants return?

  The sun took more than six Earth days to circle around Pluto’s frozen globe, bestowing and withdrawing its heat. But something more powerful now drove this warming world. Something invisible.

  What had made all this happen now? The prospect of Earth’s incursion into this bitterly cold place?

  Perhaps the entire experiment was itself a strange form of communication…

  And the Old One… How had it learned so much? Superior intelligence? But what had selected for such wit and insight out here? Where was the evolutionary pressure? Or could the pressure come from some hugely larger volume?

  No…too much. She had a gut suspicion that centuries ago, when Old One was young, something began a process of subtle tutoring. And before that, a process of deep, cerebral working among that zand’s fore-parents.

  Otherwise how could one zand, unaided, have forged so far in explaining their bitter realm? That implied some agency had begun Old One’s education long before humanity even knew the outermost planets existed.

  And to what end? Shanna looked outward at the unyielding black and wondered what huge surprises waited there. And how long they would be in coming.

  The new big nuke was behind them, coming up fast. If Proserpina burned her remaining reserves, she could forge outward into those bleak vast spaces. Keep pace with the bigger nuke approaching from below, surging up along the long sloping gravitational potential…out, ever outward into this space where bodies cold and mysterious circled in slow orbits, very nearly free of the distant sun’s governance. And with some tricky maneuvering, Proserpina could find an iceball—maybe Charon—and melt some of that vast icy store for water, for their smaller nuke rocket.

  They all could still be a part of this immense voyage.

  She peered at the slate-dark world turning below in the vast hard cold. Thinking. But not if I’m replaced as captain. She sat bolt upright, fatigue swept away. Dad! The Great A! She flipped on the recorder and started talking.

  And down among the howling winds, in the gathering gloom of methane snowdrifts now mounding about them, the zand slept on.

  PART III

  BEYOND PLUTO

  The real voyage of discovery consists not in seeking new landscapes, but in having new eyes.

  —Marcel Proust

  1.

  LONG WAVELENGTHS

  ON THE LARGEST SCALE, Julia reflected, the solar system was a spheroid cloud of debris. She looked at the big flatscreen display of an iceteroid they were passing, gleaming dully in the dim radiance of the ever-more-distant sun.

  The whole vast volume behind their ship, the High Flyer, was filigreed with bands and shells of flying shrapnel. Beyond Neptune, big ice fragments coasted in the Kuiper belt. At any moment a pair could smash together, or just clip each other, getting thrown into long ellipses, deep wobbly orbits. And this negligible-looking little blob of primordial gray ice and dust right here could, like the rest of the solar system’s slow leftovers, now and then make a sharp hook by skimming near another piece of scrap and in a few years slam into a blundering planet. Earth’s dinosaur-killer could have come from right around here.

  Julia shivered, not from the cold outside. Her pod was toasty-warm, comfy. But the strangeness that lay before them was approaching, and she had no idea of even what it might be. The voyage from Mars had taken months—a miracle, at speeds made possible by their fusion drive—and there had been plenty of time to study, learn…and worry. Proserpina, the ISA expedition, was low on supplies and would have to depart soon from Pluto, under their mission plan. But High Flyer was bringing enough to sustain them both near Pluto for months more. High Flyer was to assist Proserpina, particularly with alien translation problems. In transit they had spent much time on the long-wave emissions from beyond Pluto. High Flyer would also venture out there, getting data on the bow shock. Those both at ISA and the Consortium were apprehensive about the seat-of-the-pants style of all this, but Julia and Viktor shrugged them off. They had been living that way on Mars for decades, making do. Viktor still worked on the Marsmat problem in his spare time, and when this adventure was done, they would go back to it. But now they were focused forward.

  “Anything new from Proserpina?” Viktor hollered from the control room. He could have spoken over comm, but he just leaned back in his chair and called down the gangway. They s
pent enough time logged into electronics systems as it was. And a husband and wife like to keep in touch in the most basic ways, too.

  “Not a peep. They’re not due to report for nearly an hour.”

  Nervously she checked the all-sky scan, anyway. Yes—far back there, she could see through their nuclear rocket plume’s virulent blue-white. Pluto glimmering, and Proserpina’s signifier overlaid. Two motes swimming in the black. High Flyer had completed its delta-V with both Pluto and Charon, looping a figure eight through, to lose velocity. They swung by and turned outward, following the streams of current that Proserpina had mapped. Straight out into the vast dark…

  “Getting a lot of that odd noise again,” Victor called. “Coming up in the ultralow frequencies.”

  “The stuff Proserpina picked up?”

  “Da—stronger as we go out.”

  “I thought you said it was just more turbulence from way out at the bow shock.”

  “Earthside advises me not. Say is too low, very low frequency, for these high power levels.”

  “Then it goes in the mystery bin.”

  “I already sent to the Wiseguy compiler. Maybe someday it will tell us something, huh?” He leaned back in his flex-seat and grinned, so that she could see him down the gangway. “Before we retire, maybe even.”

  This was a standing joke between them. They would never retire unless the world ran out of mysteries, and out here that was quite unlikely. She grinned back. “Wrong. I have a big file processing right now. Remember, I sent your questions on? SETI Institute ran their Wiseguy, cross-compared with our data, and finally coughed up.”

  “I don’t believe!”

  “Come look.” About time to peek at the processing, anyway. Her curiosity was as hungry as his.

  They had reviewed Wiseguy’s capabilities, read through its mediated talks with the zand, the crawlies of Pluto. A spectacular discovery, the zand, Julia had to admit. A sentient species! Even more exciting, to talk with them. Her and Viktor’s long years of slow, difficult work on Mars had not produced anything like the same result. The Marsmat was still an enigma; many still doubted if it was self-aware.

  Not that they had been just studying old data on the way out. High Flyer was outfitted with big phased-array antennas, to study the bow shock region. Their most intriguing work had been those electromagnetic maps Viktor had been developing.

  And now he and Earthside were using Viktor’s work to discern whether there were coded messages coming in from the bow shock region. Shanna’s crew had picked up some hints; it was High Flyer’s job to sift through the sea of data, try to crack the meaning.

  “Program is smart,” Viktor said. “Thinks can find words, connections.”

  Julia blinked. She could not follow the spray of data on Viktor’s working screen. But then she looked closer and thought about how they had labored over similar problems, struggling to fathom the Marsmat.

  The software—Wiseguy the semi-AI, plus elaborate metalinguistic codes—had been cobbled together Earthside. It followed on detailed theories of how language builds up from basic mental architecture. For decades the linguists had used the primates as a model, but in the last few decades they had extended it to dolphins and whales.

  It turned out that whale song was elaborate, beautiful—and simple. The first whale song deciphered had the structural complexity of grand opera, but the message (like most opera plots, and that was no coincidence) was, I’m horny, I’m horny, I’m horny. Later code work unfolded the intricate whale ways of broadcasting I’m over this way! and Food here. And, of course, Danger! There were other tribal messages, too, but none that could not be expressed in a sentence. Nature did not always produce sophisticated dialogue.

  But why should that Earthly experience apply to the extreme low-frequency emissions from out here? The old Voyager probes had first noted the noisy spectrum, but nobody thought it was more than plasma waves, the local weather. Proserpina had captured more for detailed analysis. Thousands of Earthside analysts had sweated over those, and High Flyer’s better data. Viktor had been handling the elaborate merging of all this, and now…

  Now there was a new angle to the process. Viktor pointed it out, and she saw it suddenly, after minutes of scrutiny. Structure leaped out of the flow. The incoming digital streams broke into constellations that resembled words in their numerical architecture.

  “And they are! So the Earthside tech types say.” Julia finished her explanation to a blinking Viktor. “Our words. English!”

  “Is impossible.”

  She grinned and put on her mock-gruff Russian accent. “Is not.”

  “Must be error.”

  “Unless whoever’s sending this has heard us first, and they’re replying.”

  “At ten kilohertz? No one uses frequencies that low. Waveforms are huge!”

  “Oh?”

  “Da! Even early radio, Marconi, he used only hundreds of kilo-hertz—pretty big waveforms already.” He stopped, eyes widening with a sudden idea. “Must calculate wavelengths.” He scribbled on his slate, frowned, and scratched his short, salt-and-pepper beard. “Ummmm… Marconi could use those frequencies because he was using really big antennas. Right.”

  “Right how?”

  “Da—made of chicken wire, they were, strung between houses, like early Russian pioneers in radio—

  She chuckled. “Who discovered it all first, along with the telephone and laughing gas—yeah, I’ve heard. Point is, my earnest darling?”

  “That Marconi’s antennas had to be at least a fraction of the size of the wavelengths he used. Or else they couldn’t radiate very much—or receive much, either.”

  “That was the best he could do?”

  “Da—and this is the best they can do.”

  “Who?” Julia was thinking about antennas, which she had worked with for decades but had taken for granted.

  “The whoever that sent these signals at frequencies of ten kilohertz. Maybe they picked up our transmissions—God help us! Maybe all our radio and TV for the last century. But can’t reply at those frequencies. Because, see, at normal radio wavelengths, we’re talking antennas maybe a meter in size. Way too small for them. Instead, they go for ten kilohertz—because that’s a wavelength they can manage.”

  She blinked. “Not a joke, right?”

  “Nope. Divide the speed of light by the frequency to get the wavelength and therefore the antenna size. Old stereo systems had three speakers: the smallest, the tweeter, for high-pitched sounds; the big woofer was for bass notes—down to low-frequency rumbles.”

  Most of this was new to her, but she got the principle. “The thing that sent us these messages—the ones the Wiseguy codes are grinding away at right now—is—”

  He grinned. “Really big woofer—at least thirty kilometers across. Aliens are giants.”

  2.

  THE TOWERING ICE

  SHANNA SETTLED DOWN INTO her smart couch and went through the setup protocols. Showtime!

  Every time she went on watch, Shanna knew she was born to do this. From the beginning of this long mission she had found her hours on watch the most exciting she had ever known. Even after years on the mission, whose goals had veered radically as they learned more, her pulse raced when she went on duty. Being captain helped.

  Telepresence duty was the absolute best. Boldly exploring, while sipping aromatic Colombian. In the 3-D environment she saw the Pluto landscape in sharp detail merely by turning her head. No sensation of movement, or of cold, but sounds came aplenty: the slow sigh of breezes, the crawler’s clanking, the crunch of ice, a crisp fizz of vapor boiling off, which was a lot like bacon frying.

  It had been weeks since she had actually been on the surface, and that was the crash. So this was the next best thing: phony Pluto. Digital discovery. Earthside was superworried about safety after that crash—the Chicken Little culture was quite frustrating. Politicians actually said, about every activity, even exploration, that safety was always the number one conside
ration.

  Imagine human history if we had always felt that way, she thought. If it kept on like this at ISA, nobody on Proserpina might ever get to go back down to the surface. Come billions of kilometers and stop a few hundred klicks short…crazy.

  She peered at the landscape steadily, letting detail sharpen. Stark shadows cut across the dirty gray plain, and the sun was a glaring point. Under Charon’s gloomy crescent the thin methane atmosphere scattered little light. Darkly twisted, tortured sculptures jutted from the ice sheet. The slow-motion weather here had worked on them for eons on the somber, sleeping plain. The moon loomed huge and ominous above a sharp horizon.

  It held a certain austere beauty, but the mere landscape told nothing of its incredible cold. They had been drawn here by the unexplained growing warmth of this place—yet “warmth” was the wrong word. That grim, dismal view was only 120 degrees above absolute zero. Compared with Pluto’s temperature measured Earthside back in the twencen, a brisk 42 absolute, this was Florida. A moment’s exposure would not merely freeze her; it would snap her bones into confetti from thermal stresses.

  Yet here life stirred. Incredibly. She had been down there twice, and it was still hard to believe.

  Life on Pluto. Amazing enough by itself. Not just the simple legged forms that crawled and walked these bitter, barren hills—recent discoveries, thanks to telepresence, letting her drive the crawler from orbit. Or the flyers, angular or bulbous. No—there were others who descended from the sky, those from even farther out, beyond Pluto: the Darksider machines.

  Nobody, not even the most extreme exobiologists, could have guessed.

  Shanna resisted a morbid feeling: that the fragments of crumpled metal she and Jordin had picked up, mingled with those ice chunks, were actually scraps of…well, flesh.