Authors: Gregory Benford
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 splashed 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.
S
HANNA 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.
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?”