The Martian Race
Page 19
“Not pure water.”
“No, probably hydrogen sulfide and stuff, too.”
She wanted to snap her fingers, but of course her gloves stopped her. “Yes! It could be a fog desert in here.”
“A what?”
“Ever been out in a serious fog? There's not much water falling, but you get soaked anyway. There are deserts where it doesn't rain for years, like the Namib and the coast of Baja California. Plants and animals living there have to trap the fog to get water.”
She thought quickly, trying to use what she knew to think about this place. In fact, frogs and toads in any desert exploited a temperature differential to get water out of the air even without a fog. When they came up out of their burrows at night they were cooler than the surrounding air. Water in the air condensed on their skin, which was especially thin and permeable.
Julia peered at the thin mist. “Are you getting a readout of the temperature? What's it been doing since we started down?”
He fumbled at his waist pack for the thermal probe, switched it to readout mode. “Minus fourteen, not bad.” He thumbed for the memory and nodded. “It's been climbing some, jumped a few minutes ago. Hmm. It's warmer since the fog moved in.”
They reached the end of the ledge, which fell away into impenetrable black. “Come on, follow the evidence,” she said, playing out cable through her clasps. Here the low gravity was a big help. She could support her weight easily with one hand on the cable grabber, while she guided down the rock wall with the other.
“Evidence of what?” Marc called, grunting as he started down after her.
“A better neighborhood than we've been living in.”
“Sure is wetter. Look at the walls.”
In her headlamp the brown-red rock had a sheen. “Ice! Enough water to stick! Last week some of this stuff was all the way up to the entrance.”
“I can see fingers of fog going by me. Who woulda thought?”
She let herself down slowly, watching the rock walls, and that was why she saw the subtle turn in color. The rock was browner here, and when she reached out to touch it there was something more, a thin coat. “Mat! There's a mat here.”
“Algae?”
“Could be.”
“Hot damn!”
She let herself down further so that he could reach that level. The brown scum got thicker before her eyes. “I bet it comes from below.”
She contained her excitement as she got a good shot of the scum with the recorder and then took a sample in her collector rack. Warmer fog containing inorganic nutrients would settle as drops on these cooler mats. Just like the toads emerging from their burrows in the desert?
Analogies were useful, but data ruled, she reminded herself. Stick to observing. Every moment here will get rehashed a millionfold by every biologist on Earth … and the one on Mars, too.
Marc hung above her, turning in a slow gyre to survey the whole vent. “Can't make out the other side real well, but it looks brown, too.”
“The vent narrows below.” She reeled herself down.
“How does it survive here? What's the nutrient source?”
“The slow-motion upwelling, like the undersea hydrothermal vents on Earth.”
Marc followed her down. “Those black smokers?”
She had never done undersea work, but everyone was aware of the sulfur-based life at the hydrothermal vents. Meter-long tube worms and ghostly crabs. They harvested from the bacteria that existed on chemical energy in the warm volcanic upwelling. The vent communities on Earth were not large, a matter of meters wide before the inexorable cold and dark of the ocean bottom made life impossible.
She wondered how far away the source was from here. Kilometers?
Down. Slow, careful, watch your feet.
In the next fifty meters the scum thickened but did not seem to change. The brown filmy growth glistened beneath her headlamp as she studied it.
Poked it. Wondered at it.
“Marsmat,” she christened it. “Like the algal mats on Earth, a couple of billion years ago.”
Marc said wryly, puffing, “We spent months and only found fossils, up there in the dead lake beds. The real thing was hiding from us down here.”
Ten meters more. Reeling out the impossibly thin black cable, the life cord.
The walls got closer and the mist cloaked them now in a lazy cloud. “You were right,” Marc said as they rested on a meter-wide shelf. They were halfway through their oxygen cycle time. “Mars made it to the pond scum stage, and it's still here.”
“Not electrifying for anybody but a biologist, but better than just fossils. This is more than just algal scum. It implies a community of organisms, several different kinds of microbes aggregated in, okay, slime—a biofilm.”
She peered down. “You said the heat gradient is milder here than on Earth, right?”
“Sure. Colder planet anyway, and lesser pressure gradient because of the lower gravity. On Earth, one klick deep in a mine it's already fifty-six degrees C. So?”
“So microbes could survive farther down than the couple of klicks they manage on Earth. They're stopped by high heat.”
“Maybe.”
“Let's go see.”
“Now? You want to go down there now?”
“When else?”
“We're at oxy turnaround point.”
“There's lots in the rover.”
“How far down do you want to go?”
“As far as possible. There may be no tomorrow. Look, we're here now, let's just do it.”
He looked up at his readouts. “Let's start back while we're deciding.”
“You go get the tanks. I'll stay here.”
“Split up?”
“Just for a while.”
“Mission protocol—”
“Screw protocol. This is important.”
“So's getting back alive.”
“I'm not going to die here. I'll go down maybe fifty meters, tops. Got to take samples from different spots.”
“Viktor said—”
“Just go get the tanks.”
He looked unhappy. “You're not going far, are you?”
“No.”
“Okay then. I'll lower them down to the first ledge if you'll come back that far to pick them up. Then I'll come down too.”
“Okay, sounds fine. Let's move.”
He turned around and started hauling himself up the steep wall. “Thirty minutes, then, at the first ledge.”
“Yeah, fine.”
“Julia …”
“See you in thirty minutes,” she said brightly, already moving away.
Into utter darkness. Marc's helmet light receded quickly. The slope below was easy and she inched down along a narrow shelf. Paying out the cable took her attention. Methodical, careful, that's the ticket. Especially if you're risking your neck deep in a gloomy hole on an alien world.
Despite the risks, she felt a curious lightness of spirit—she was free. Free on Mars. Maybe for the last time. Free to explore what was undoubtedly the greatest puzzle of her scientific life. She couldn't be cautious now.
Her brother Bill flashed into her mind. Marc reminded her of him, but was much more wary. Bill had taken life at a furious pace, cramming each day full, exuding boundless energy. They went on exploring trips together as children, later as nascent biologists. He was unstoppable: up and out early, roaming well after dark. There was never enough time in the day for everything he wanted to see. “Slow down, there's always tomorrow,” people would tell him.
But his internal clock had served him well, in a way. He was cut down at age twenty-two when his motorcycle slid into a truck one rainy night when sensible people were home, warm and dry. Looking around the church at his funeral, Julia felt he'd lived more than most of the middle-aged mourners. Bill would've approved of her right now, she was sure.
A flicker from her handbeam brought her back. She looked down, shook it. The beam brightened again. Damn, not now.
“Marc! Bring some batteries, too. My handbeam's getting feeble.”
A long pause. Had he heard? She relied upon the signal going up the thin wire in her monofilament cable, then getting rebroadcast from the rover to him. A useful backup for times like this, when they were out of line of sight. But did the connection still hold, after 500 days exposed to the brutal weathering here?
“Yeah, copy. Had to get up that last long climb.”
“Easy does it.”
The harness and yoke under her arms was making it impossible to move around. She wrestled it off and held it in one hand while she worked her way around a protrusion. It felt good not to be tied up. She was getting the knack of moving down here. Slow, steady, letting her eyes pick out telling details.
The mat was thicker here, as she'd guessed it would be closer to the elusive source.
She landed on a wide ledge and moved briskly across it, mindful of time passing. The floor was slippery with Marsmat but rough enough so she could find footing. Sorry, she said silently to the mat, but I've got to step on you.
Her handbeam flickered again, died. She shook it, leaned forward to look at it with the headlamp, then felt a sudden hard blow to her forehead.
The lamp went out.
She fell backwards. It was like a dream, plenty of time but nothing to grab.
Slow-motion, into the Martian darkness.
19
JANUARY 19,2018
SHE BECAME AWARE OF A FAINT TINNY CONVERSATION INTERSPERSED with crackles.
Ghost voices … sounded like … she concentrated … Viktor … and Marc.
Of course! It was her suit comm. How dopey of her not to recognize them right away! Now what were they saying? Something about Airbus and a landing. More crackles. She was too far underground to hear clearly. She gave up. Marc would tell her later.
She lay there, waiting for the surprise to go away, automatically checking her suit readouts. All normal, no damage. She'd dropped the handbeam in the fall. Must've run into an overhang. Utter pitch dark.
Where was her damned handbeam? There was a faint glow to her left. That must be it.
She started to get up, noticed a feeble luminescence ahead of her. Confused, she sat back down. Take this carefully.
All around her, the walls were developing a pale ivory radiance.
She closed her eyes, opened them again. The glow was still there.
No, not the walls—the Marsmat. Tapestries of dim gray luminosity.
She reviewed what bits she remembered about organisms that give off light. This she hadn't boned up on. Fireflies did it with an enzyme, right. Luciferase, an energy-requiring reaction she had done in a test tube a few thousand years ago in molecular bio lab. Glowworms— really fly larvae, she recalled—hung in long strands in New Zealand caves. She remembered a trip to the rain forest of Australia: some tropical fungi glow in the dark. Hmm. Will-o’-the-wisps in old graveyards, fox fire on old wooden sailing ships … could there be fungi here?
Damned unlikely. She couldn't even get mushrooms to grow in the greenhouse. Wrong model. She shook her head. Waves breaking at night into glowing blue foam during red tides in California. Those are phosphorescent diatoms. What else? Thermal vent environments …
Deep-sea fish carried luminescent bacteria around as glowing lures. That's it. The lab folks had fun moving the light-producing gene around to other bacteria. Okay. So microbes could produce light, but why here? Why would underground life evolve luminescence?
Bing bing bing—the warning chime startled her out of her reverie. She flicked her eyes up. The oxygen readout was blinking yellow.
Thirty minutes’ reserve left. Time to go back.
As she got up she brushed against her handbeam. She picked it up but left it off. Navigating by the light of the walls was like hiking by moonlight.
Gingerly she made her way up to the harness and yoke. It had been dumb to take them off, of course. But sometimes even stupidity paid off. She might have missed the luminescence if she hadn't fallen, her handbeam knocked off.
Pulling herself up gave her time to think, letting the winch do the work. She could feel her excitement bum in muscles that seemed more supple than usual. Warmer here, for sure. She turned her suit heater down. Life hung out in the tropics.
Before she reached the tanks, she heard Marc's impatient voice. “Julia, where are you?”
“On my way. Pretty close.” She rounded a jut in the vent walls, into the glare of his lights. The walls faded into black.
“Where were you? You're way late, damn it. The tanks were here on time—hey, where's your headlamp?”
“Ran into an overhang. Smashed it. Marc—”
“Handbeam too? What'd you do—grope your way back? Why didn't you call?” He was clearly angry, voice tight and controlled.
“I found, I found—”
“Julia, calm down, you're—”
“Turn off all your lamps.”
“What?”
“Turn ‘em off. I want you to see something.”
“First we switch your tank.”
She sighed. It was just like Marc to fuss over details. Looking down at the sidewalk for pennies and missing the rainbow.
When she finally got the lights off he could see it too. There was a long moment of utter shock. He seemed to know it was better to say nothing.
Then she heard something wrong. The faint hissing surprised her. Mission training reasserted itself.
“What's that? Sounds like a tank leaking.” Automatically she checked her connections. All tight. “Marc? Check your tank.”
“I'm fine. What's the matter?”
“I hear something, like a leak.”
“I don't hear anything …”
“Be quiet. Listen.”
She closed her eyes to fix the direction of the sound. It came from near the wall. She shone her handbeam on the empty tank, bent down low, and heard a thin scream. Oxygen was bleeding out onto the Mars-mat.
“Damn. Valve isn't secured.” She reached down to turn it off. Stopped. “What… ?”
The Marsmat near the tank was discolored. A blotchy, tan stain.
“Damn! We've damaged it.” She knelt down to take a closer look, carefully avoiding putting her hand on the wall.
“What happened?” Marc took one long step over, understood at a glance. “My vent gas?”
“Uh-huh. Looks like it.”
“What a reaction. Damn! And fast!”
“Oxygen's pure poison to these life-forms. It's like dumping acid on moss. Instantaneous death.”
He looked around wonderingly. “We're leaking poison at them all the time in these suits.”
She nodded. Stupid not to see it immediately, really. Like scuba gear, their suits vented exhaled gases at the back of the neck, mostly oxygen, a bit of nitrogen, and some carbon dioxide. A simple, reliable system, and the oxygen was easily replaceable from the Return Vehicle's chem factory.
Marc shook his head, sobered. “Typical humans, polluting wherever we go.”
“If the stuff is this sensitive, we'll have to be really careful from now on.” Julia straightened up carefully and backed away from the lesion.
They stood for a long moment in inky blackness, letting their retinas shed the afterimage of the lamps. Finally Marc asked, “Where's the light coming from?”
“Marsmat glows. Phosphoresces, is more correct.”
“How can it do that?”
“Don't know. The more interesting question is why.”
A long pause in the darkness that seemed to press in on all sides. Marc said, “Did you hear? Airbus is incoming, within hours.” “No, too much static. I could barely recognize your voices. What'd Viktor say?”
“They got a message relayed from the satellite. Airbus will be in tonight. We're to be back by then.”
“Damn. I'd hoped …” She sighed. “What did you tell him?”
“Not much. I didn't want him to know you were down here alone, so I was pretty brief.”
“How's Airbus going to deliver Raoul's repair kit?”
“They don't say. Maybe drop it to us?”
“What's their landing site?”
“Viktor says they just don't answer that. Or other questions, either.”
“So okay, big mystery, standard Airbus bullshit. That doesn't have any effect on us here.”
“I guess not. Good to know Raoul'll get his kit, though.”
“Yeah. Let's think in the here and now, though.”
She knew now that time and oxygen would set the limits. They had this day and now were to return to the base. Solid orders. Team loyalty.
“Plenty of oxy up there,” Marc said later as they rested and ate lunch—a squeeze-tube affair she hated, precisely described in one of her intervideos as eating a whole tube of beef-flavored toothpaste.
“So we trade tanks for time.”
“Viktor's gonna get miffed if we don't check in at the regular time.”
“Let him.” She wished they had rigged a relay antenna at the vent mouth. But that would have taken time, too.
Tick, tick, tick.
“I don't want us to haul out of here dead tired, either.”
“We'll be out by nightfall.”
“We won't be so quick going back up.”
Field experience had belied all the optimistic theories about working power in low gravity. 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. It meant that they could not count on a quick ascent at the end of a trying day.
“You want geological samples, I want biological. Mine weigh next to nothing, yours a lot. I'll trade you some of my personal weight allowance for time down here.”
He raised his eyebrows, his eyes through his smeared faceplate giving her a long, shrewd study. “How much?”
“A kilogram per hour.”
“Ummm. Not bad. Okay, a deal.”
“Good.” She shook hands solemnly, glove to glove. A fully binding guy contract, she thought somewhat giddily.
“Viktor's counting on using some of your allowance to drag back more nuggets and ‘jewels,’ y'know.”