So now, though nobody liked it all that much, Shanna was in charge. Astronaut type, subspecialist in biology and medical, a practical bio degree, though not really primarily a scientist—but a general science fan, yes. Jordin and Mary Kay Kare, they were the real secret strength out here—the tech types who could repair anything but weren’t narrow. The rest of the crew tended the big, roaring bulk of Proserpina and didn’t take a lot of Shanna’s time, luckily. She wasn’t really a manager type.
The symphony ended with stirring punch. She could not resist the pleasure of slapping her hand down. A heartbeat later a musical chime—rigged by Shanna in protest against the usual peremptory beeping alarms—told her that the data gathered since Proserpina’s last radio contact had now been encoded and kicked back toward Moon-base One. She tapped a key, giving herself a voice channel, reciting her ID opening without thinking. “Okay, now the good stuff, gang. As we agreed, I am adding my own verbal comments to the data I just sent you.”
They had not agreed, not at all. Many of the Pluto Mission Control engineers, wedded to their mathematical slang and NASA’s jawbone acronyms, felt that real, live human commentary was subjective and useless. Ephemeral stuff. Let the expert teams back home interpret the data. But the public relations people loved anything that tickled the public’s nose.
“Pluto is a much livelier place than we ever imagined.” She took a breath; always good to have a clear opening statement. “There’s weather, for one thing—a product of the planet’s six-day rotation and the mysterious heating. Turns out the melting and freezing point of methane is crucial. With the heating-up the mean temperature is high enough that nitrogen and argon stay gaseous, giving Pluto its thin atmosphere. Of course, the ammonia and carbon dioxide are solid as rock—Pluto’s warmer, these days, but still incredibly cold, by our comfortable standards.”
There was the sound bite maybe. Now the technical.
“Methane, though, can go either way. It’s a volatile gas. Earthside observers found methane frost on the surface as long ago as 1976—anybody remember?—and methane ice caps in 1987. They speculated even then that some of it might start to thaw as the planet made its closest approach to the sun. Well, it did, back in the late twencen—and still does, every Plutonian morning. Even better, the methane doesn’t just sublime—as it was supposed to because of the low atmospheric pressure. Nope, it melts. Then it freezes at night. That makes it a life-supporting fluid, in principle.”
Now the dawn line was creeping at its achingly slow pace over a ridgeline, casting long shadows that pointed like arrows across a great rock plain. There was something there she could scarcely believe, hard to make out even from their thousand-kilometer-high orbit under the best magnification. Something they weren’t going to believe back Earthside. So keep up the patter and lead them to it.
Their crew had debated how to announce this for days—with no result. So now that they were sleeping, she would. Earthside deserved to know, she reminded herself. It wasn’t an ego thing at all. But still…she was the captain.
“Meanwhile, on the darkside there’s a great ‘heat sink,’ like the one over Antarctica on Earth. It moves slowly across the landscape as the planet turns, radiating heat into space and pressing down a column of cold air—I mean, of even colder air. From its low, coldest point—the pressure point—winds flow out toward the dayside. At the sunset line they meet sun-warmed air—and it snows. Snow! Maybe I should take up skiing, huh?”
It was hard, talking to a mute audience. And she was getting jittery. She took a hit of the thick, jolting Colombian coffee in her mug. Onward—
“On the sunrise side those winds meet sunlight and melting methane ice, and so it rains. Hard. Gloomy dawn. Tough weather—and permanent, moving around the planet like a veil.”
She close-upped the dawn line, and there it was—a great gray curtain descending, marching at about the speed of a fast car.
“So we’ve got a perpetual storm front moving at the edge of the nightside and another that travels with the sunrise.”
As she warmed to her subject, all pretense at impersonal scientific discourse faded from Shanna’s voice; she could not filter out her excitement that verged on a kind of love. She paused, watching the swirling alabaster blizzards at twilight’s sharp edge and, on the dawn side, the great solemn racks of cloud. Although admittedly no Jupiter, this planet—her planet, for the moment—could put on quite a show.
“The result is a shallow sea of methane that moves slowly around the world, following the sun. Who’da thought, eh, you astro guys?” A slight slam at the astrophysicists, who had foreseen none of this. Who could have, though?
“Since methane doesn’t expand as it freezes, the way water does, methane icebergs just sink.” Okay, the astro guys know that, she thought, but the public needs reminders, and this damn well was going out to the whole wide bloomin’ world, right? “Once it freezes, it sinks. So I’m sure it’s all slush a short way below the surface, and solid ice from there down. But so what? The sea isn’t stagnant, because of what that big ol’ moon Charon is doing in its synchronous orbit. As big as Charon is—and as close to the planet as it’s gotten since its orbit shifted, big-time—Charon makes a permanent tidal bulge directly underneath it. Think of a big ridge of fat liquid, swarming over the whole planet.”
Like the Earth ocean tides, she thought. But much bigger, and somehow strange. “And the two worlds are trapped, two dancers forever in each other’s arms.” Like the Earth-moon system, only Charon’s far bigger in relation to Pluto. “So that bulge travels around from daylight to darkness, too. So sea currents form, and flow, and freeze. On the night side the tidal pull puts stress on the various ices, and they hump up and buckle into pressure ridges. Like the ones in Antarctica, but much bigger.”
Miles high, in fact, in Pluto’s weak gravity… A huge wedge soaring to the dark sky. Marching toward a dim horizon, grinding, grinding. Strange…
But her enthusiasm drained away, and she bit her lip. Now for the hard part.
She’d rehearsed this a dozen times, after all the arguments with the other crew—and still the words stuck in her throat. After all, she hadn’t come here to do close-up planetology. An unmanned orbital mission could have done that nicely. Shanna had come in search of life.
Five decades before, in the twencen and its aftermath, the life-is-everywhere advocates had not had any real evidence. Until the Mars-mat discovery in 2018. And the success of the SETI program, picking up a faint message. Then the skies opened.
Attention pored over those mysteries, and in turn back on the old problem of communicating with dolphins, whales, and the like. By then there was a whole academic discipline devoted to reading the well-nigh unreadable.
Well, maybe that would help the ship coming out now, on Proserpina’s tail, with a crew of has-been Marsmat folk. But for now she had different news.
The theory and code developed to wrestle with the SETI message’s elegant mumbo jumbo was known somewhat condescendingly as Wiseguy. It had discovered that the SETI signal was a repeating “funeral pyre”—left behind to proclaim the wonders of an extinct civilization, thousands of light-years farther in toward the galactic center. Applied to the microwave emissions from Pluto, Wiseguy suggested an intelligent origin. Coherent, ordered emissions, it said—yet a code Wiseguy could not break. Nor could any human.
But those signals were refracted and damped by the plasma streams billowing forth from the sun, so the Space Array near Earth got only glimmerings of the Plutonian emission. This was enticing—even convincing—to the converted. The International Space Agency had decided to go full out and send a manned expedition, putting Wiseguy within range.
She paused, held her breath almost as if she expected a chorus of sighs, groans, shouts. But the community that had hoped she would find a striking refutation to the nay-sayers—that band was clustered around a view screen an unimaginable distance away.
“This isn’t a chemical biosphere at all. That’s why
it can exist.”
She coughed, excused herself self-consciously from people who would not hear the cough until five and a half hours hence. Then she made her voice more brisk, scientific.
“Mind you, the heating is the real point. There’s some driver in the whole magnetosphere, and I think we’ve found it. A current is flowing in from farther out. I’m talkin’ way, way beyond Pluto’s orbit. Maybe from the Oort cloud—that’s the junk left over from the formation of the solar system, out where the comets come from.”
To her ears this chatty bravado rang false, but maybe it would play better back Earthside.
“We’ve detected some pretty huge currents in toward Pluto. And little old Pluto packs a wallop, too. It’s got a strong magnetic field, nearly perpendicular to its spin axis—we sent you the data on this already. It’s a generator, like Uranus. And out here in this neck of the woods, any energy source is big news.”
She stopped, sensing the skepticism these last sentences would provoke six hours from now. She sighed. This was even harder than she’d feared. Her mind kept lurching off on tangents, spilling out scientific data and ideas. Behind the facade she was a fountain of emotion. Could they tell?
She took a deep breath and changed the subject. “And in the atmosphere there’s a lot more free hydrogen than a planet this little ought to be able to hold. At some spots on the dayside we’ve measured gaseous carbon dioxide, although it all ought to be frozen. There are also some strange spectral lines—”
Shanna caught herself before saying what those lines seemed to show. She was not ready to make that leap of faith; not yet. “Anyhow, since my last report to you I have sent down one of the smaller probes. It landed on a little hill, one about to be submerged by the just-melting methane sea’s froth. Smacked down next to an ice crag which I’m pretty sure is ammonia and carbon dioxide. Telemetry will tell all. The probe reported to me faithfully until an hour and a half ago, and then…” She paused to gather up her courage, imagining her father’s famous Axelrod rumbling, avalanche-on-the-way belly laugh and Dr. Jensen’s deep-grooved frown. Even though both her mentors were more than 6 billion kilometers away, they were with her as she framed her next sentence. Taking a deep breath—
“And then I—I believe something ate it.”
3.
THE WAY OF THINGS
SLANTING LONG IN PALE shades of crimson and violet, Lightgiver’s rays broke through thinning, rosy methane clouds as the rains of morning slackened. Still the zand swam tirelessly on toward Rendezvous with the others of its kind.
Joy! It had not felt this strong for many, many long days. Vigor and potency throbbed through it. When it found another of the zand and they Self-merged—as usually happened before day’s end—there might even be a Birthing this time. How wonderful that would be!
Sudden, tearing pain lashed at the zand’s belly. The hooked head of a borer twisted into the hole it had gouged. Agony lanced up from the wound. The borer’s tail whipped the red sea into foam, powering the parasite’s body around and around and in, in, deep and terrible.
The pain soared, and the slow, seeping faintness began. The zand’s automatic neural defense system took over. Lifegas and burngas sighed from its side compression chambers into its central canal. A neural impulse connector parted, zapping a spark. Lifegas and burngas ignited in a jet of searing fire. The zand lifted up and away, out of the sea.
The borer clung on, its narrow winding body writhing and lashing against the much larger zand. The living rocket left a trail of ivory, a plume freezing into ice crystals. The zand rose. Air pressure dropped, sucking the borer from its hold. It fought and held and then tumbled away into the sea.
The zand struggled to breathe, to live. Air rushing past soothed the seeping wound. Lightgiver be thanked for fast reactions, the zand thought.
It trimmed its course to swing back down toward the sea, feeling strength return. It was still charged with the rejuvenating energies, sucked from the strange thing it had eaten earlier that morning. The land below lay rumpled and veiled by the dawn’s mist.
The zand was tempted to remain airborne. Fly! You live! Fly!
But it would need its lifegas later on, should there be no food at Rendezvous. By now most of the rockfood on the dayside was submerged beneath the lapping sea of warm red methane. But later the sea would die, going sluggish and then rigid with cold—as it always did. The day would warp on and wrap up into night, leaving the methane to freeze again, promise denied. Only the surge of tides could stir it. And even that was pointless, without real warmth.
Such was the Way of Things. Peace lay in resignation to this truth.
Again it sang a canticle to Lightgiver, weaving strand-songs in with its general praise. To the almighty Nourisher of the World it gave its own specific thanks at having been spared for further life. The zand vowed to the sky that it would teach young zand to revere Lightgiver’s holy name, should Lightgiver see fit to grant it a Birthing.
It banked on vagrant winds and sang. Ecstasy. Banked and sang.
A faint voice interrupted its meditations. The zand responded with its own distinctive pulses, rip-rap-tink, and received in return a conversational rush of joy from another zand. Old One had evidently survived the night again.
Old One—there, in the dark sky.
By mutual agreement both zand sealed themselves in firm raps of closing membranes. They expended enough of their precious lifegas to lift and float them just above the surface of the sea, resting.
“I am glad you have survived another day,” the zand began, as was proper for a younger person to say.
“And I also, that we greet one another, You the Younger. We may not look forward to an indefinite number of such days,” Old One replied.
“Am I always to be the Younger?” the zand asked.
“Relish it,” the Old One said. “Such a name does not come again.”
Life on their ever-changing world was precarious, but Old One’s tone implied something far more comprehensive and profound. In the Younger, intellectual curiosity—with an undernote of fear—prevailed over the deference due to age. “Explain,” Younger begged.
They hovered over the lapping sea. Winds snarled, buffeting them.
“Think back, youngling. Think back to your last Birthing. How did Lightgiver look in the sky?”
The young zand pondered. Self-merge and Birthing were such all-absorbing experiences that one did not, at the time, pay much attention to one’s surroundings. Not even to Lightgiver?—the zand’s conscience prodded, and a twinge of shame filled it for its evident lack of devotion. And then it remembered.
“Lightgiver was brighter—and warmer—and…and…”
“And larger?” Old One prompted.
“And larger, yes. A bit.”
“Now let me share something with you before I die.”
Old One brushed aside its companion’s polite protests. “No, no—listen! I cannot go through many more days and nights of gorge and sleep, gorge and sleep. So attend me while you can, and tell this to the other zand. I am the Old One. Probably the oldest in the world. And I have watched the skies with care. Beyond the cycle of dark and light that we know is a far longer cycle. We have no proper way to measure it. But I have thought this out, and I can tell you that Lightgiver moves in and out, from Its greatest width to Its narrowest. All this great cycle occurs in more than fourteen thousand of our short cycles of light and day. I myself have seen two of these greater cycles.”
“That much?” Younger was amazed. It almost lost its purchase upon the winds that lofted them above the dawn sea.
“Yes—a great long while.”
“You must have learned—”
“I learned this—that while Lightgiver is at Its farthest and coldest, the ice does not melt, and there is no sea, and even in full day all life sleeps.”
Younger again nearly lost itself upon the winds. This was a dark idea, as black as the world’s somber nightside itself.
Younger
sensed a weariness in Old One’s soul, a weight of pure remorseless time itself. So it tried to express cheer: “And then Lightgiver comes back? Yes? And is close and warm, and life wakes again?”
“Yes. But in the first of these long cycles—great ages, through which I have lived—we numbered eight thousand zand. We lost some to borers and flappers and starvation, and, of course, each night—then as now—some never made it through to the morning. Once in that cycle came a great raid from Darkside—”
“Then! It is—!”
“Yes, youngling, the story told in the epic chant is true. Intelligences exist back there, feeding on Lightgiver knows what—and we drove them off in the terrible battle of which legend tells, with much loss of life.”
“But…the Birthings?”
“Almost enough to maintain our numbers. But not quite. And so there remained more than seven thousand of us, lean and hungry, when that long cycle reached the Great Night. When even at full daytime, all freezes.”
Younger felt awed. “You all…slept?”
Looking toward the gathering day, Younger could see broad plains of warming rock, glimmering beyond the methane sea. And in the distance, strange high towers that it could not understand. Could they be a part of this grand narrative, the tale Younger was privileged to hear from the Old One itself? It hoped so. It hoped for some scrap of meaning in all things.
“Yes, and Lightgiver shrank to Its smallest size—I assume, for, of course, I could not watch during the frozen time. Then Lightgiver began to grow again, to the point at which It could again give us warmth and zest. But as the second cycle began, fewer of us awoke. How many zand are there today?”
The daily Rendezvous ensured that all of them knew. “Yesterday there were 3,441.”
“Half what there were before the last long freeze. And Lightgiver bestows less warmth and light every day. Your personal experience is that of other zand: Self-merge leads to Birthing only when our world is most warm.”
“So we do not grow in numbers sufficient to replace ourselves?”
The Sunborn Page 10
