Moonseed n-3

by Stephen Baxter

  It was an exciting ride.

  The turns were sharp. Every time Geena steered, all four wheels swivelled. The ground here was all bumps and hollows, an artillery field of craters, and every time they hit an obstacle one or two wheels would come looming off of the ground.

  Henry, strapped to his lawn chair on top of this thing, was thrown around, especially when Geena took a swerve to avoid a rock or a crater.

  “Holy shit,” he said.

  “Don’t be a baby,” Geena said. “It’s only eight miles an hour. We’d be beaten by a San Francisco cable car.”

  “Yeah, but how many hummocks per hour are we hitting?”

  Geena pushed up the speed. The Rover bounced high off the ground, and threw up huge rooster tails of black dust behind them.

  “Let me explain something to you,” she said as she drove. “Our consumables are being used up all the time.”

  “Sure.”

  “So at no point are we going to drive further than our walkback limit.”

  “Which is the distance we can walk back to the shelter, with the oxygen in our backpacks. In case the Rover breaks down. I know. That makes sense to me.”

  “Yes. But because our consumables go down steadily, that walkback limit gets tighter and tighter with time. And we are going to stay within that limit, all the time.”

  “Sure,” Henry said.

  “If that means we have to leave the rille before you’re ready, we do it. If it means we have to miss out on interesting-looking detours, we do it.”

  “Geena—”

  “And I’m going to be conservative, because the navigation computer on this thing doesn’t work any more. As far as walkback is concerned I’m the boss.”

  He shrugged, a clumsy gesture in his suit. “Sure. You’re the boss.”

  If she wanted to feel in control, if that was her way of avoiding the funk she suffered on the way in, it was fine by him.

  …There were, Henry realized afresh, craters everywhere.

  Some of the craters were subdued depressions, almost rimless, as if dug out of loose sand. They were easy to traverse; the Rover just rolled down a gentle slope. But others — mostly smaller — were sharper, with well-defined rims, the classic cup shapes of story books. The younger craters were full of rubble, like builders” slag, concentrations of angular blocks, and they had littered rims. Geena had to drive around those babies.

  They couldn’t avoid a big crater, maybe two hundred yards wide. As they approached the rim Geena slowed down; they had to thread their way through an apron of ejecta a couple of hundred yards deep, sharp-edged, scattered blocks up to four or five yards in size, dug out of the Moon and thrown up here.

  From above, Henry knew, this blanket would form the crater’s ray system, the scattering of ejecta around the central wound, like a splash of blood around a bullet-hole. It gave him a thrill to know that he was here, actually driving among the rays of a lunar crater. A hell of a thing.

  Here at last was the lip of the crater. They went over the rim into the basin. It was strewn with blocks ranging from a yard across to maybe fifteen yards, with a few yards separating the blocks, wide enough for them to drive through, as if passing through some miniature city block.

  Crossing the crater floor there was an ejecta ridge, a rough, loose structure made of highland dust and mare basalt fragments, churned up together. It must be part of the ray system that came radiating away from the impact that created the younger Aristarchus. He noticed a piece of rock that sparkled with glass beads. It was possible that after the impact, so many billions of years ago, this chunk had been thrown thousands of miles into space, smashed, molten, cooling, before falling back to the Moon, to land here, and, after waiting as long as it had taken for life to evolve on the Earth, here it was for him to see.

  Now they drove through a dune field — as he thought of it, in defiance of lunar geology — pitching over a uniformly corrugated ground, ridges and troughs. Here, he thought, was a place they could easily get lost. But the sun hung in the sky above them, unmoving, a beacon.

  He thought about that. Morning would be a week long, on the Moon.

  For seven days that sun was going to climb up the black sky. For seven days the shadows, of rocks and craters and two human beings, would shrink, vanishing at local noon. The rocks would get as hot as two hundred degrees Fahrenheit. Then the sun would start to sink, sliding at last under the western horizon, and the two-week-long lunar night would cut in. The temperatures then would get down as far as two hundred degrees below zero.

  Four hundred degree temperature swings, every month. On Earth, on a field trip in the desert, you could get swings of more than a hundred degrees, and at night you would sometimes hear distant, muffled crumps: rocks, exploding under the pressure of the endless contractions and expansions.

  But there would be no shattering rocks here. Maybe there had been such incidents once, but every rock that was going to shed layers had done it a hundred million years ago, or more; and there was no volcanism to push up mountains and deliver fresh rocks to the air, no frost to work into rock cracks. After aeons of erosion the Moon was smooth. The mountains of Aristarchus, on the horizon, were like fluid sculptures, rounded and smooth, set out under the black sky, majestic in their own way. If he looked towards the sun’s glare, they were partly silhouetted, their forms delineated by smooth crescents of sunlit terrain, like sand dunes at dawn.

  And the mountains weren’t grey or brown as he had expected, but a pale gold, in the low lunar morning light. Rounded, dust-covered, they reminded him of ski slopes — maybe in the mountains of Colorado, high above the timber line. And that golden sheen gave them a feeling of warmth, for him; they seemed to cup the Rover like an open hand.

  He could, he realized, get to feel at home here. You could set down your lander almost anywhere on the Moon and expect to find a reasonable surface to work with.

  And it had its own antique beauty, he found, subtle and unexpected. A place where time ran slow, where morning was a week long. But he wished he could see the stars. He imagined walking here in the lunar night, with the stars above: a huge canopy of them, reaching down to the horizon, undiminished by even the slightest trace of dust or mist.

  But it would take all of twenty-eight days for a star to circle around the sky — and the stars here didn’t turn around Polaris, that great hinge in the skies of northern Earth, because the Moon’s axis was tipped compared to Earth’s.

  …But, even as the stars slowly worked around the sky, the Earth would hang above you, fixed forever. That unmoving Earth would spook you, hanging there in the sky, blue and white, forty times as bright as a full Moon: winding through its remorseless phases, like an immense, blinking, unwavering eye.

  To an inhabitant of the Moon, Earth was the blue eyeball of God, he thought.

  They stopped every few hundred yards, so Henry could emplace seismometer stations. The little moving-coil devices, jug-shaped and trailing wires, were placed three at a time, to pick up the ground’s movement in three dimensions. He even had some experimental lightweight gravimeters, little stainless-steel cans, that were capable of getting down to an accuracy of ten milligals or so.

  Henry was wiring the Moon.

  Here and there, he also laid down small explosives. His intention was to do a little active seismography, using the explosives to send shock waves through the Moon’s interior, to be picked up by the seismos. The larger the net of sensors he could cast, the better the image of the interior of the Moon he would be able to build up; in a way the messages of the little seismometers were likely to be more significant than anything he would see, at the rille.

  As they approached the rille, still following the old Apollo tracks, they had to drive up an incline. It was an outcrop of Cobra Head, the old volcanic dome here, the source of the lava which had gouged out the rille.

  The thirty-year-old Rover performed impressively on the slope, seeming to carry them without effort. But, a hundred yards short of t
he edge of the rille, they stopped. The old Rover tracks snaked on further up the incline, but Geena was reluctant to risk taking the aged car any further.

  When Henry tried to get up, he could barely raise his suited body out of the seat, and when he got to stand, he felt as if he might slip down the slope. The steepness here was deceptive.

  “Henry. Help me.”

  “What?”

  “I think this damn thing is going to run downhill.”

  Geena was holding onto the Rover. Henry could see one of its wheels was lifting off the surface.

  Henry grabbed onto the Rover; it was so light he felt he could support it easily.

  He pointed out an eroded old crater they could park in, and when Geena drove forward, they found the Rover was left almost level.

  Henry turned to look back. He was three hundred feet high now, and the view was staggering. The sloping land swept away, obviously a sculpture of craters: craters on craters, young on old, small and sharp and cup-shaped on old and eroded and subtle. And he could see that big rubble-strewn crater they had driven through, looking as fresh as if it was dug out of the plain yesterday. Its sharp rim was a ring of dazzling white, and rays of boulders, black and white, clean and sharp, were scattered across the landscape for miles in all directions.

  Further out the slope’s broad flank swept down and merged with a bright, undulating dust plain that was pocked with the gleaming white rims of craters, all of it diamond sharp, under a black sky. It was a wilderness, suspended beneath that starless interplanetary sky above.

  And it was crossed by just two, closely paralleled, human-made car tracks.

  Geena was already working on the Rover, carefully wiping Moon dust from its new batteries.

  Henry took his equipment from the sample bags in back of the Rover, and from beneath its seats. They both had big Beta-cloth bags they loaded up with gear, and then slung over their shoulders. Geena had a coil of nylon rope she looped over one arm. And they both had torches, taped to their helmets.

  Thus, laden with their gear, they loped away, towards the rille.

  Henry stopped periodically, setting in place miniature acoustic flow monitors and seismometers, sensitive to high-frequency vibrations. This was part of the monitoring network he was going to build up around the rille, and whatever lay within it.

  For a while they were still tracking the Apollo astronauts” exploration. But now they came to a point beyond which there were no Rover tracks, only footprints: two sets, tracking up and down the incline. Henry could see how the Apollo astronauts” tracks had diverged, as they loped about the hill, taking what samples they could in their haste. But he and Geena had only one purpose now.

  They marched directly up the slope, ignoring the meanders of their predecessors, following the line of steepest ascent.

  It was a difficult climb. The dust was thick: the slope was almost bare of rock, and the dust and rubble was churned up, mixed and messy dust that gave the mountain its smoothed-over shape. Maybe it looked attractive from afar, but on foot it was difficult terrain. What it meant was that with every step he took dust fell away from his feet, like soft sand, as if he was climbing the side of a dune.

  He was out of breath in a few steps.

  Still, he persisted.

  He paused for a breath. He turned and looked back at the skeletal Rover. It looked like an ugly toy: squat and low, sitting there in a churned-up circle of dust. Its orange fenders and gold insulation were the brightest things on the surface of the Moon. A few yards behind him, Geena was labouring up the slope after him, her arms full of gear, her red commander’s armbands bright.

  …He was on the Moon, he remembered suddenly; this was no routine hike.

  The return of perspective was unwelcome.

  He remembered some of the early, now lost, theories of the Moon’s surface. One geologist called Thomas Gold had warned that the Moon would be covered in a layer of fluffy dust dozens of feet thick. Armstrong and Aldrin would have to drop coloured weights to the surface before they landed; if the weights sank, they would have to abort their landing immediately, before their LM was swallowed. Gold had clung to those views even after unmanned craft had safely settled on the surface, but happily for Apollo 11 he had been proven wrong…

  Maybe.

  Now that he was approaching the nest of the Moonseed, Henry wondered whether Gold had been more correct than he knew. What if the layers of basaltic strata beneath his feet, infested by Moonseed, were indeed Gold’s dust?

  He continued.

  He reached a flat crest, and came suddenly on the rille: Schröter’s Valley. It was a gap in the landscape in front of them. It wound into the distance, its walls curving smoothly through shadows and sunlight.

  As he walked further, the surface of the mare sloped gently towards the rille rim, and the regolith was getting visibly thinner. The rille walls themselves sloped at maybe twenty-five or thirty degrees.

  He stopped, where the slope was still gentle.

  The sun was behind him. The far walls were in full sunlight, and Henry could see layers: distinct layers of rock, poking through the light dust coating. They looked like layers of sedimentary rocks on Earth, sandstones or shales, laid down by ancient oceans, the myriad deaths of sea creatures. But what he was seeing, here, had nothing to do with water, or life. The story of the Moon, laid out for him here, was different.

  These layers were lava flows. Over hundreds of millions of years, a succession of outpourings had flowed out of the Moon’s interior, covering and recovering the valley floor, building up the ground here.

  But then, pulsing out of Cobra’s Head, a lava river had coursed down the slope of the older landscape, a brief band of light cutting savagely into the older layers. The flow cooled from the edges, the hardening rim confining the central channel. Eventually the channel even roofed over with hardening rock, and the lava stream cut deeply into the underlying mare basalt.

  But the brief eruption of heat subsided rapidly. The remnant of the lava drained away and cooled, leaving a tunnel in the rock. Along much of its length the roofed-over tunnel collapsed, exposing its floor to the sunlight.

  This will do, he thought.

  Henry walked along the rille edge, until he came to a place where a boulder, four or five feet tall, was embedded in the inner wall of the rim. He sat down in the dirt, resting on his hands; the regolith crunched beneath his butt. He put his feet flat against the rock and started to push. It was hard to get any traction; the friction between his butt and the ground was so low he kept sliding backwards. Eventually he found a way to brace his arms at an angle behind him, and get more purchase.

  Geena joined him. “What in hell are you doing?”

  His exertions weren’t budging the rock, but they were lifting him up off the ground, to which the low G only casually stuck him. “Help me. It’s a tradition.”

  “More science, Henry?”

  “Hell, no. Come on.”

  She sat down beside him. She pressed her feet into the face of the boulder and pushed, alongside Henry.

  “Rock rolling,” Henry said between grunts of effort. “No geology field trip is complete until you’ve sent a boulder crashing down into a caldera, or a forested hillside—”

  The boulder came out of its regolith socket with a grind he felt through his knees. With an eerie grace, the rock tipped forward. He tried to keep pushing, but it was gone, and there was no pressure under his feet; he slid a little way down the slope.

  He leaned forward to see. As the rock started to fall it was a little like watching some huge inflatable, on Earth, bounding slowly down a hillside; but at length, as the low gravity worked in the resistance-free vacuum, the rock picked up speed. He watched it until it had plunged out of sight, in the deep shadow of the rille. It left a trail in the regolith, a line of shallow craters that looked as if they had been there for a billion years.

  He listened for a while, but there was, of course, no noise, no crack as it reached that remote
bottom.

  “Um,” said Henry. “Kind of fast. Suddenly I feel vertiginous.”

  On his butt he worked his way back up the slope, and stood up, yards from the eroded rim. He had left a track like a sand worm in the regolith. When he stood up his butt and legs were coated with dark grey dust; he tried to beat it out but only succeeded in grinding the stain deeper into the fabric.

  Geena was surveying the area. She pointed. One set of tracks continued from this point, deeper into the rille.

  The ghost of Jays Malone was close here, he thought.

  She said, “You ready?”

  “Let’s get it over.”

  She took the rope from her shoulders, and knotted it professionally around Henry’s waist, taking care not to snag his backpack or his chest controls. Then she wrapped a length of it around a Chevy-sized rock, and took some slack herself.

  For a moment they faced each other. Henry could see himself reflected in her gold visor, slumped forward in a simian pose under the weight of his backpack. But he could not see Geena’s face.

  Behind her, he could see the camera on the Lunar Rover fixed on them, watching analytically.

  He ought to say something. But this was Geena, for God’s sake. They were divorced. In full view of the world, what were they supposed to say now, as he prepared to confront an alien life form?

  She said: “I’ll be here.”

  “I know.” He licked his lips.

  He thought he could see her nod, inside her helmet.

  He picked up his tools and turned.

  He walked forward, towards the rille. He went over a smooth crest, and started descending into the rille itself. But there was no sharp drop-off; like every other surface here the rim was eroded to smoothness, and the footing was secure. The rope trailed behind him, reluctant to uncurl and lie flat in this weak gravity.

  Just to be sure of his footing, he clambered back up the slope. There were no problems.

  He turned, and bounded several yards back down the slope. Even from here he couldn’t see the bottom of the rille; it was still hidden by the broad shoulder of the valley.