Titan

by Stephen Baxter

  From this far out she could make out more of the shape of the lake. It was obviously a horseshoe shape, curving around that central mountain—although from here, if she was honest, it was hard to tell if the lake was a true open horseshoe or if it closed over, around the far side of the mountain, into an annulus.

  Looking back to shore was like looking across a sheet of blackened glass, to an encrustation of purple ice and foam at the lake’s rim. She could see Rosenberg standing patiently, stained with gumbo up to his waist, where the cable termination glittered. Seen from here, Rosenberg was very obviously alone on that primeval beach. His figure was the only vertical in a landscape of horizontals, starkly isolated. There was nobody else standing with him: no houses or buildings or cars behind him on that landscape of soft undulations, no trees, no birds in the sky. Arid in the frigid, mushy depths below her there was no life she could recognize, perhaps no life at all.

  The boat rocked with a slow, soothing gentleness, with a period of maybe five or six seconds. The lake surface was almost a perfect black, its ripples heavy and shallow, free of breakers. Most organic solids, raining down from the atmosphere, would simply sink to the bottom of the lake. But here and there Benacerraf could see scatterings of foam, gray, and purple. Some of that was spindrift, aerosols caused by bubbles bursting on the surface.

  She felt her sense of place and time shift around her. It was as if the landscape of Titan was reaching her, through the isolating layers of her suit; she started to get a sense that she was truly here, alive and sentient, on this ethane lake, a billion miles from her birthplace. It took moments of stillness like this to understand this, she thought. Moments that the Apollo guys, Marcus White and the rest, were never given, in their hectic, task-crammed timelines. Moments that had come only, perhaps, in the quiet of their sleep periods, as those fragile Lunar Modules ticked and creaked around them. Moments, little fragments of true humanity, they were never encouraged to report. What a pity.

  She wondered how long she’d been out here.

  She felt as if her sense of time was dissolving, stretching like melted candle-wax. Pendulums would swing more slowly here, like the rocking of her boat, in the gentler gravity. Perhaps some pendulum hidden deep in her own being was slowing, too, in response to this small world.

  But now Rosenberg waved. He had set up the small TV camera on its stand, looking out at her. And the portable antenna pointed straight up, to where Cassini hovered far above the clouds and haze in its fifty-thousand-mile Clarke orbit.

  The comms gear was a reminder that this wasn’t some dumb jaunt on a lake. She was out here to look for amino acids and other good stuff. And this was a NASA extravehicular activity, on the surface of an alien world; they had a duty to return data on what they were doing, whether anybody was listening or not.

  Anyhow, she thought, this is the first time in all of human history that a grandmother has gone boating on the surface of a low gravity moon. It ought to be on TV Jackie should see this. And the boys, she thought wistfully.

  She began the series of experiments Rosenberg had set out for her. The first was a series of sample collections; she gathered up droplets from the lake into plexiglass test tubes, and bottom sediment that she trawled up using tubes fixed to a line.

  She started up the tilt meter. This little gadget was something like an electronic spirit level. It contained two vials of a conductor fluid; as the boat tipped back and forth under the influence of the lake’s slow waves, the electrical resistance of the fluids in the tubes changed, and could be measured. Next she dipped a refractometer into the liquid to measure its speed of light. The refractometer was a cute thing, a little transparent box with prisms inside it, which she filled up with Clear Lake fluid. She measured the fluid’s ability to conduct heat; by tilling up a tube with fluid she immersed a platinum wire, and watched how its resistance changed as she passed current through it. She deployed a simple gadget which measured the speed of a sound wave traveling between two piezoelectric transducers. The sound speed would tell a lot about the ocean, and when she reconfigured the gadget, Benacerraf might be able to make a sonar estimate of the depth of the lake, if the grunge-coated bottom proved reflective enough. She measured the ethane’s dielectric constant—its ability to hold an electric charge—by filling up a plate condenser with fluid, and measuring its capacitance. And so on.

  One of Benacerraf’s favorite instruments was a pair of thin metal vanes mounted on a piezoelectric crystal. The crystal drove the vanes, and their resonance depended on the density of the fluid in which they were immersed.

  The results of the experiments ought to help determine more about the lake’s nature. The lake wasn’t a simple pool of ethane. There were fractions of other paraffins—methane, propane, butane, others—as well as dissolved nitrogen, and a slew of higher organics. For instance, the refractive index of the lake fluid was very sensitive to the percentage of dissolved methane.

  She had to bend over the side of the boat to work, and soon her back was aching once more. She tried to keep her hands clear of the cryogenic fluid of the lake itself. She worked with tongs and pipettes, as it dealing with some acid. She fumbled a little with her gloved hands.

  Her last experiment was a plumb line, pleasingly crude and intuitive, just dropped over the side. The line was loaded with a scrap of Command Module aluminum, and the depth was marked out by simple knots in the steel cable. It was a little hard to tell when the string was fully paid out, so soft and muddy was the bottom. When she estimated the weight had reached a reasonably firm surface, she read off the depth. Ten feet.

  She described the result, and what she could see, to Rosenberg.

  “That’s good, Paula,” he said. “T he ethane is deposited at a rate of three feet every ten million years. So that makes your lake maybe thirty million years old, which is pretty young for a crater of such size. When it formed, the crater would have had the kind of shape we recognize on the Moon—a shallow saucer, with maybe a central peak. After that, the ethane lake gathered. But the bedrock ice on Titan flows, on the timescale of a few million years. Viscous relaxation That pushed up the center of the crater into that ice dome you see. So the ethane was shoved into an annulus, a ring around the domed mountain…”

  “And the horseshoe shape?”

  “Saturn’s tides. If Titan was covered by an ocean, the surface would be drawn into an egg shape by Saturn’s gravity, with the sharp ends pointing towards and away from Saturn. Our isolated lake is a fragment of that egg-shaped surface. It’s as if the crater is tipped up a little bit; all the fluid is pushed to one end of the annulus channel by the tidal acceleration.”

  Benacerraf felt awed. She looked around at the horseshoe shape of the lake once more. Saturn was invisible, but its gigantic influence was everywhere, its gravity field shaping the very nature of the landscape over which she moved. Benacerraf felt tiny, irrelevant, as if cupped in the palm of huge, invisible forces.

  On impulse, she bent, stiffly. She got hold of the lip of the boat’s wall, and got down to one knee. Immediately she could feel the cold of the hull, and of the mass of ethane below: it was as if the heat was being drained out of her body through the bone of her knee, the layers of her suit, and she could feel the hot, ineffectual triangles of her laboring suit heater.

  She leaned out of the boat, and looked into the ethane. Fat ripples, concentric with the circumference of the boat, oozed across the surface of the lake, suffused with the slow time of Titan. The ethane was utterly black, returning no reflection of her helmet, her face. It was unnerving, as if this wasn’t a liquid at all; it was as if she was poised over a hole in the world, a pit of black space that stretched down to infinity.

  She reached out with a gloved hand. She passed her fingers through the ethane. In her peripheral vision she could see that a warning light flashed on her chest panel.

  She pulled her hand out of the lake.

  She lifted up her glove. The residual ethane gathered into fat little globule
s on her fingers and palm; its high surface tension had pulled it into these tight, mercury-like balls. Set against the blue of her glove, this sample of the lake was a kind of dull brown, but not completely opaque, like dirty petrol. She thought she could see particles, swirling about in the interior of the globules, but the light was poor.

  Even as she studied the globules they were shrinking. The boiling point of pure ethane was around ninety below—which was about ninety degrees above the ambient temperature. It was a big temperature jump, but even so, so quickly, the ethane droplets were absorbing the heat which was leaking out of her suit. The rapid evaporation was disturbing, a tough reminder of the fragility of her situation here. And every molecule of ethane that left her hand would carry away a little more of the heat her body needed.

  She shook her hand free of the remaining droplets; they scattered from her glove in slow-motion parabolic arcs.

  When she looked at her hand again, she found that the evaporating ethane had left a purplish scum on the fabric, in little discrete spots. Complex, prebiotic hydrocarbons: once more, she was immersed in the stuff of life.

  “Paula,” Rosenberg called now, urgency in his voice.

  “What?”

  “Take a look up there. The clouds.”

  Benacerraf had to tilt back on her heels to see.

  The methane clouds were still more broken now, and were streaming, across the orange haze ceiling beyond.

  “Wind coming up,” she murmured. “That was sudden. What do you think, Rosenberg? Fifteen knots?”

  “More like twenty, I’d say. And that means waves. Paula, get out of there.”

  It was probably good advice. Waves on Titan were not like Earth’s.

  She looked around, towards the center of the lake.

  The waves were already coming, radiating out from the domed ice mountain at the heart of the horseshoe. Bred by Titan’s low gravity, they were like slow-motion tsunamis: walls of black ethane, each of them at least a hundred and fifty feet tall. It was hard to tell, but Benacerraf estimated the waves were a half-mile apart. They were moving across the surface of the lake at maybe thirty miles an hour—a glacial pace by Earth standards, where waves of such size would have moved seven times as fast.

  Maybe the boat could ride this out, just float over the back of those huge, stretching beasts.

  Maybe not.

  She began to drag her paddle through the paraffin lake once more, and she could see Rosenberg hauling clumsily on his cable, his feet scrabbling at the gumbo for footing.

  Within a couple of minutes, with a heavy bump, the boat had grounded against the shore of Clear Lake.

  Benacerraf looked back. The waves were heaping up still, glistening black walls sweeping grandly towards the shore. But they would break when they reached the shallows.

  With Rosenberg’s help, she began to haul the boat up the beach, far enough that the breaking waves couldn’t reach.

  “Get moving, you old bastard.” Bart went around the room, his white jacket stained by some yellow fluid, and he de-opaqued the windows with brisk slaps.

  It took Marcus White a while to figure out where he was. It often did nowadays. So he just lay there. He’d been in the same position all night, and he could feel how his body had worn a groove in the mattress. He wondered if Bart had ever seen Psycho. “I thought—” His mouth was dry, and he ran his tongue over his wrinkled gums. “You know, for a minute I thought I was back there. Like before.”

  Bart was just clattering around at the bedside cabinet, pulling out clothes, and looking for his stuff: a hand towel, soap, medication, swabs. Bart never met your eyes, and he never watched for the creases on your pants.

  “My father was there.” Actually he didn’t know what in hell his father was doing up there. “The sunlight was real strong. And the ground was a kind of gentle brown, depending on which way you looked. It looked like a beach, come to think of it.” He smiled. “Yeah, a beach.” That was it. His dream had muddled up the memories, and he’d been simultaneously thirty-nine years old, and a little kid on a beach, running towards his father.

  “Ah, Jesus.” Bart was poking at the sheet between White’s legs. His hand came up dripping. Bart pulled apart the top of White’s pyjama pants. White crossed his arms over his crotch, but he didn’t have the strength to resist. “You old bastard,” Bart shouted. “You’ve done it again. You’ve pulled out your fucking catheter again. You filthy old bastard.” Bart got a towel and began to swab away the piss.

  White saw there was blood in the thick golden fluid. Goddamn surgeons. Always sticking a tube into one orifice or another. “I saw my buddy—Tom, you know—jumping around, and I thought he looked like a human-shaped beach hall, all white, bouncing across the sand…”

  Bart slapped at his shoulder, hard enough to sting. “When are you going to get it into your head that nobody gives a flying fuck about that stuff? Huh?” He swabbed at the mess in the bed, his shoulders knotted up. “Jesus. I ought to take you down to the happy booth right now. Old bastard.”

  Like a beach. Funny how I never thought of that before. It had taken him forty years, but he was finally making sense of those three days. More sense than he could make of where he was now, anyhow. Not that he gave a damn.

  Bart cleaned him up, dressed him, and fed him with some tasteless pap. Then he dumped him in a chair in the day room. Bart stomped off, still muttering about the business with the catheter.

  Asshole, White thought.

  The day room was a long, thin hall, like a corridor. Nothing but a row of old people. Every one of them had his own tiny softscreen, squawking away at him. Or her. It was hard to tell. Every so often a little robot nurse would come by, a real R2-D2 type of thing, and it would give you a coffee. If you hadn’t moved for a while, it would check your pulse with a little metal claw.

  The softscreens were still basically TVs but you had to set them with voice commands, and he never could get the hang of that; he’d asked for a remote, but they didn’t make them any more. So he just had his set tuned to the news channels, all day.

  Sometimes there was news about the program, if you knew where to look. Which he generally didn’t.

  He’d heard they were doing more EVAs on Titan, which was a hell of a thing, but he hadn’t seen a single damn picture about that. Of course it was different back then. When the Eagle set down, he’d watched the walk itself at Joan Aldrin’s house at Nassau Bay. When Buzz first came on screen she kicked her feet and blew kisses at the screen. Those creaky old pictures, like some kind of silent movie. And then he’d gone on to one hell of a Moonwalk party with some of the guys…

  But there wasn’t even anybody up in LEO nowadays, except a couple of Red Chinese, maybe.

  He couldn’t find anything about Titan. He folded up the screen in disgust.

  He tried to read. You could still get paper books, as opposed to softscreen, although it cost you. But by the time he’d gotten to the bottom of the page he would forget what was at the top; and he’d doze off, and drop the damn thing. Then the fucking R2-D2 would roll over to see if he was dead.

  The door behind him was open, letting in dense, smoggy air. Nobody was watching him. Nobody but old people, anyhow.

  He got out of his chair. Not so hard, if you watched your balance. He leaned on his frame and set off towards the door.

  The day room depressed him. It was like an airport departure lounge. And there was only one way out of it.

  Unless you counted the happy booth. A demographic adjustment, Maclachlan called it.

  Maclachlan was an asshole. But White couldn’t really blame them, Bart and the rest. Just too many old bastards like me, too few of them to look out for us, no decent jobs for them to do.

  Outside the light was flat and hard. He squinted up, the sweat already starting to run into his eyes. Not a shred of ozone up there. The home stood in the middle of a vacant lot. There was a freeway in the middle distance, a river of metal he could just about make out. Maybe he could hitc
h a ride into town, find a bar, sink a few cold ones. But he had the catheter. Well, he’d pull it out in the john; he’d done that before.

  He worked his way across the uneven ground. He had to lean so far forward he was almost falling, just to keep going ahead. Like before. You’d had to keep tipped forward, leaning on your toes, to balance the mass of the PLSS. And, just like now, you were never allowed to take the damn thing off for a breather.

  The lot seemed immense. There were rocks and boulders scattered about. Maybe it had once been a garden, but nothing grew here now. Actually the whole of the Midwest was dried out like this.

  At least this was still the United States of America, though. At least he was still an American. Things could be worse. At least he hadn’t become a fucking New Columbian.

  He reached the freeway. There was no fence, no sidewalk, nowhere to cross. He raised an arm, but he couldn’t keep it up for long. The cars roared by, small sleek things, at a huge speed: a hundred fifty, two hundred maybe. And they were close together, just inches apart. Goddamn smart cars that could drive themselves. He couldn’t even see if there were people in them.

  He wondered it anyone still drove Corvettes.

  Now there was somebody walking towards him, along the side of the road. He couldn’t see who it was.

  The muscles in his hands were starting to tremble, with the effort of gripping the frame. Your hands always got tired first, in microgravity…

  There were two of them. They wore broad-rimmed white hats against the sun. “You old bastard.” It was Bart, and that other one who was worse than Bart. They grabbed his arms and just held him up like a doll. Bart got hold of the walker, and, incredibly strong, lifted it up with one hand. “I’ve had it with you!” Bart shouted.

  There was a pressure at his neck, something cold and hard.

  The light strengthened, and washed out the detail, the rocky ground, the blurred sun.