The Sunborn, Page 5

  “Looks like an easy one,” Viktor called out as they ground to a stop beside the broad mouth of the thermal vent. Splashes of yellow and dingy brown marked the sand near the mouth. He pointed. “Vapor deposition from active periods, too.”

  Uchida was robo-master, and he put them to work unloading. Julia paced around Vent R, letting her senses take in details it was easy to miss. Inside a suit made it harder to get the feel of a new vent, the traceries of vapor deposition, stains, erosions. Nothing could live on the surface, of course, in the stinging oxidants and lethal ultraviolet. But the Marsmat could not contain its moist hoard perfectly.

  Gusev Crater had thermal vents because the huge ancient impact had cracked the underlying layers, letting magma worm upward. The best place to go deeper into Mars seemed to be at the bottom of Valles Marineris. That great stretched scar cut deep and broad. The barometric pressure there could even allow a briny slush on a summer afternoon, melting long-frozen chemical reserves and maybe letting Marsmat get close to the surface.

  She was curious about how the mat had used the deadly surface for an energy source without getting stung by the ultraviolet and alkaline dusts. There were whole conferences Earthside on just that basic physiological riddle. To get any work done here, she had to keep an open mind. Mars did not reward fixed preconceptions.

  She looked up at the hard black sky. Faint filigrees fought up there. Probably ionization curls, she thought, from the solar storm streaming past Mars right now and slamming into the thin atmosphere.

  Survey done, she went back to grunt labor. Compared with decades before, the rover’s cable rig was first-class. It worked from a single heavy-duty winch, with a differential gear transferring power from one cable to the other depending on which sent a command. It was the same idea as the rear axle in a car and saved mass.

  Four telepresence robots were standing beside the fissure. They had six spindly arms, four stubby legs, and a big central control box, all in sleek polycarbon, and she no longer found them odd. These had done the first study, lowering themselves on cables to check for life. Long experience had shown that letting ’bots do a lot of the roving saved time and accidents.

  Sometimes Julia wondered if Mars could have been explored at all without plenty of ’bots. Sitting warm and snug in the habs, she and Viktor and rotations of crews from Earth had tried out dozens of candidate vents.

  In two decades they had found that most fissures, especially toward the poles, were duds. No life within the top kilometers, though in some there were fossils testifying to ancient mats’ attempted forays. Natural selection—a polite term for Mars drying out and turning cold—had pruned away these ventures. The planet’s axial tilt had wandered, bringing warmer eras to the polar zones, then wandering away again. Life had adapted in some vents, but mostly it had died. Or withdrawn inward.

  Not this vent, though.

  Somebody back at Gusev made the ’bots all turn and awkwardly bow as the humans approached. Julia laughed with the others, and, as if right on cue, Praknor came on the comm. No preliminaries.

  “You deliberately stood me up.”

  “Sorry, it was a scheduling mix-up,” Julia said.

  “I cannot believe—”

  “Hey, got work to do here. Talk later.” Julia cut off the long-range comm frequency and switched to local, 2.3 gigahertz. And felt an impish joy that turned up her lips. When she told Viktor, he smiled, too, with an expression she had come to cherish. Long relationships had their rewards.

  First, as always, they set up the base camp. The team was quick and precise, hustling in the forward-leaning trot that was the most energy-efficient way to move on Mars. Every expedition now, there was new tech to make jobs easier, like the ball tents. She watched them deploy, nearly without human effort.

  Under pressure any object wants to shape into a sphere. The ball tents took advantage of this. The ball was made of a flexible, thermally insulating material that could take wear and tear, especially the constant rub of dust. Light wires or ropes anchored the ball to the ground as an air tank inside inflated it, with the people already inside. A small chem cracking plant squatted beside each ball, running steadily to split the atmosphere’s CO2 for oxygen. Adding hydrogen from water let the cracker build up stocks of methane gas and oxygen, which could then burn to drive the rover. To get powerful methane fuel demanded only the CO2 plus water from buried ice, which was everywhere. With energy, all the chemistry became easy.

  The robots had already arranged the electrical power supply, comm and computation center, and other backups, all now standard for a descent. Telepresence had come a long way. Bossed from the Gusev tele-team, robots helped the humans put two tanks apiece on their lines, double-clamping them meters above the personal yokes. She did not like the idea of that much mass ready to fall on her and checked the clamps three times. Even robots make mistakes; maybe especially robots.

  She got into the yoke, all sized and adjusted for her. Like putting on a jacket now, easy. Her shoulders ached a bit, maybe from her swimming. She had gone back to the pool a few times, whenever she started brooding about Andy Lang. Exercise erased cares.

  “Is ready?” Viktor called. Everyone answered, “Aye!” and they began. The watch crew back at Gusev sent them a salute, a few bright bars of John Philip Sousa.

  Backing down the slope, playing out their cables, Julia looked up into a bowl of sharp stars—always there, even at high noon. The ’bots got the oxy tanks past the Y-frame that routed the lines. There was a neat get-around, far easier than the awkward old days.

  Rappelling, bouncing in the light grav, having fun. Down the first hundred meters in good time, just playing out the monofilament cables in a straight drop. She and Viktor were lowest and went down fast, clicking on their suit lamps as the light from above faded. After weeks of indoor work it actually felt good to be doing something—clean, direct, muscles and mind.

  A large folded diaphragm lay at the bottom, where the fissure took an abrupt turn sideways. “Pressure seal,” Julia said, and Viktor nodded.

  “Four-leaf design,” Viktor observed, playing a strong beam of light over the interleaved folds. “Not see that one for a time.”

  Julia took several pictures. “Pretty thick. Got little grapplers at the edges, see? Sturdy.”

  In the girlhood Australian ecology, water was the rare resource. Underground Mars, its pressure was precious. Life evolved to seal off passages, allowing a buildup of local vapor density. Then it could hoard the water and gases it needed, building up reserves from the slow trickle from below.

  The mat kept itself secured from the atmosphere with folded sticky layers, preventing moisture loss. The vaults below were thick with vapor, but by ordinary gas dynamics that could not be sustained for long. The valve must cut off the losses to the surface, to manage this eerie environment. A pressure lock.

  But how did the valve know to close? How to respond to pressures and moisture densities? She was convinced that the glows and vapors somehow carried messages, organizing this whole shadowy realm. Biological organisms always had good sensors for toxics they made, their own wastes. The mat exhaled methane and probably had sensors that opened its valves at the right time—or so said a paper with her name on it, and she was halfway convinced. Still, progress in deciphering the mat’s meanings had been painfully slow, these two decades.

  This mat valve was classic, grown at a narrow turn in the vent. As nearly as Julia and other biologists had been able to determine, these were like Earthly stomates, the plant cells that guard openings in leaves. Plants open or close the holes by pumping fluid into or out of the stomate cells, changing their shape.

  Still, analogies were tricky, because the mat was not a plant or an animal—both Earthly categories—but rather another form of evolved life entirely. Not just another phylum, but another kingdom altogether. Some thought it should be classed with the Earthly biofilms, but the mat was hugely more advanced.

  Daphne knelt beside a pool covered with sli
me, next to the valve. The top was a crusty brown, and it dented when she poked it with a finger. Underneath it was most likely a pool of water.

  “Standard defense against desiccation,” Daphne said. Julia had written a paper on that, but she said nothing as Daphne teased apart the mat and scooped up some of the underlying liquid in a sample vial and tucked it into her pack. Let them work, she thought. Anyway, independent confirmation is always good. Julia’s paper had concluded that the pools of liquid in mats supported mobile algal colonies, like Volvox and other pond life on Earth. But maybe this one would prove to be different, a local adaptation. Mars was a big place.

  Julia swept her handbeam around. The mat hung here like drapes from the rough walls. Viktor was taking high-res pictures. “The upper lip of the mat flows down,” Julia pointed out. “It covers this pool, keeps it from drying out. We’ve seen this at about every site.”

  Daphne scooped out some of the filmy water and put it under her hand microscope. “Wow, mobile algal colonies—like Volvox.” She took samples.

  Julia smiled and walked Daphne through the controls of the pulser. Viktor showed one of the crew how to rig the electrical leads to the dark tan wedges of the diaphragm. The best place was along the thin fans, ribbed like the underside of a mushroom.

  This was one of the big controversial issues, the subject of many Earthside review panels. Many biologists thought that any tampering with the mat was immoral. Certainly, they said, jolting it with currents could cause major damage.

  But there was no other way to get into the inner chambers. From the start Viktor and Julia had used what worked. For two years they had held out at Gusev on their own, making several descents and setting the protocols followed in dozens of later descents. Julia had reasoned by analogy with some attractive little white sea urchins, Lytechinus, from which she had extracted eggs and sperm, back in grad school days. Back then she’d used a standard technique, running a small current through the water, stimulating the urchin’s topmost pore—which duly released its eggs or sperm. The urchins hadn’t seemed to mind, and neither did the mat, decades later.

  Earthside howls of protest meant nothing to them. “Theory easy when your life not on the line,” Viktor had said in a public message at the time. There were demonstrations, people wearing Viktor masks, carrying signs saying Torturer and Martian Criminal, Mat Murderer. When an interviewer asked about these, Viktor just laughed. They both published a New York Times opinion piece, reasoning that there were probably many chambers threading Mars, and the mat was large and robust—or else it could not have survived since the warm, wet era over 3 billion years ago.

  Certainly current was better than squirting the valve with oxygen, as they had at first, in an emergency. That had caused visible damage, killing some of the mat, turning it dead gray. “Field trumps theory,” Viktor had said.

  Viktor triggered the voltage impulse. A hushed silence, just the wheeze of breathing coming over the comm. Then the leathery folds slowly withdrew, inching back, contracting like muscles.

  The capacitor was a bulky wedge on Daphne’s backpack; she was tall and muscular. She peered intently at her ammeter, careful not to over-stress the thickly interwoven tissues. Viktor changed the pattern of the pulser, looking for the best sequence. The folds showed no particular response, but they did sluggishly open. The diaphragm took several minutes to spread, forced by the current flow. A two-meter passage yawned. Pale vapor poured from the opening.

  “Nineteen milliamps at 0.35 volts,” Daphne called crisply. Then in a different tone she whispered, looking at the slow withdrawal, “Wow…”

  Julia remembered that this was Daphne’s first fresh vent. She had trained on Vent A, the “classic” entry where they discovered the mat system. She was doing a thesis on the mat’s reaction to repeated violations of its integrity by humans—oxygen exposure from leaks and exhalations from their early suits.

  Though Daphne had been here a year, Julia did not know how the woman felt about the whole idea. After all, they were rupturing the mat’s system. Some biologists argued for a go-slow strategy, checking to see when a vent opened of its own accord and venturing in only then. They had tried that for a year and got in a grand total of two descents. On the second one they’d had to electrically trigger the diaphragm to get back out. Julia and Viktor had argued the issue in endless interviews and position memos. In their view it basically came down to whether they did any research or not, whether humanity ever learned more about the mat.

  The United Nations had even gotten into the matter, solemnly instructing the Consortium to stop all mat activities. That got them headlines, but they had no way to enforce their words. Axelrod retaliated by declaring that either the U.N. back off or he would lay claim to Mars. He left ambiguous whether he meant the whole planet or just part. This Mexican standoff never got resolved. After a while the Consortium gave the nod to resume descents. The incident stimulated the founding of the International Space Agency, though the contributing nations carefully kept control away from the U.N., of course.

  Only years later did the world discover that Julia and Viktor had conducted a dozen descents without telling anybody. When they published their results, there was a predictable furor, but that died away, too. Most biologists had decided that staying in perpetual high dudgeon over matters several hundred million kilometers away was pointless.

  “Honor of first entry goes to…” Viktor played out the suspense for a moment, before bowing. “To Daphne.”

  She was thrilled. The diaphragm was well clear of her body when she dropped down on her cable. She followed her endless drills and immediately mounted a belaying assembly on the wall below.

  “It goes vertical again,” she called. “Come on through. I’m on a bare ledge, easy standing, no mat underfoot.”

  The entire crew followed her and fitted their cables through the assembly so they would have a new, common descent point. All these procedures had been worked out by mountaineering experts Earthside and many trials Marside. They kept mechanical damage to the mat at a minimum. Already, overhead, the diaphragm started easing back together, trying to get a seal around their cables. It wouldn’t work, because the cables still needed to have free play.

  Still, it was reassuring to see the mat here trying the same solutions that Julia had seen elsewhere. It wasn’t injured, or else it couldn’t respond so quickly. Plus, it was further evidence that the mat system exchanged information globally, or else had evolved this defense mechanism so long ago—against what?—that it was instinctive. Despite decades of wondering which explanation was right, she did not know.

  Julia paused for a moment. Mars was tiring. Whether this came from the unrelenting cold or the odd, pounding sunlight (even after the UV was screened out by faceplates), or the simple fact that human reflexes were not geared for 0.38 g, or some more subtle facet, nobody knew. But today she was feeling it. She and Viktor were nearly twenty years older than the rest of the team, and she wished for a moment that the Mars Effect would kick in right now.

  Down into inky depths. They passed by lush mat. Gray sheets, angular spires, corkscrew formations of pale white. These stuck out into the upwelling gases and captured the richness. Some phosphoresced in pale blue and ivory. Other brown growths had earlike fans to catch moisture, a common feature. One spindly, fleshy growth looked like the fingers of a drowned corpse, drifting lazily in the currents… She got it all on vid.

  The Mars-studies industry Earthside had classified all these types, coining terms like “extensors,” “fungoidal extrusions,” “asymmetriads,” “symmetriads,” and, inevitably, “mimoids” for the times when the mat copied something human. Usually the mat made a rough humanoid shape, as had happened in the second Vent A descent, in the first expedition. But now and then they were greeted with blocky copies of instruments, backpacks, tools. Somehow the mat could sense these, leading to a whole school of thought among biologists that the mat had optical sensors.

  So far they hadn’t found
any. That might be because, despite Viktor’s Mat Murderer image, he and Julia had not taken many samples. They respected the mat. Several scientists had died while studying it in the first expedition.

  “Notice how large and complex the structures are,” she called to the crew. “Daphne, that’s a purple spore-thrower at your left.”

  “Check. Big, multiple pods. Wow.”

  This was half exploration, half a training exercise. Daphne was bright and quick, and Julia wanted to cultivate her as a long-term member of Gusev. She always needed more biologists than she had, especially for descents.

  Giving a guided tour of a place she’d never been before felt a bit awkward, but she had been on dozens of descents, and training was essential. Most of the crew would return to Earth within a year or so, before the trial of returning to full g became too much. They had to learn and work before then. She could tell by their expressions that they were still in openmouthed awe, even though the others had several descents between them. Was she getting jaded? No, she reassured herself, just accomplished. An air of certainty calmed the others.

  The harness and yoke under her arms was new and wonderfully flexible, giving her freedom. They worked their way around a protrusion. Daphne led the way—slow, steady, letting their eyes pick out telling details. The brown and gray mat was getting thicker on the slick, moist walls. The rest of the team followed, leading a new batch of climbing ’bots they’d use for recon later.

  Julia was happy to leave that to others; her whole interest here was to sense a certain something she could never define. Call it presence—the looming feel of the mat, the sensation of being inside its workings. Julia supported her weight easily with one hand on the cable grabber, while she guided down the rock wall with the other. She concentrated. Every moment here will get rehashed a millionfold by every biologist on Earth…and the ones on Mars, too.