The Martian Race (25 page)

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.”

“Good move.”

“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.”

“It's my allowance.”

“Hey, just a friendly remark. Not trying to get between you two.”

“Thanks for the thought, but I'll deal with Viktor. Ready to go? We're eating into my hard-bought hours.”

They returned to the ledge where Julia had her accident, two hundred meters further in. On the other side of the fortuitous overhang they found a pool covered with slime on a ledge. It was crusty, black and brown, and gave reluctantly when she poked it with a finger.

“Defense against the desiccation,” she guessed.

Marc swept his handbeam around. The mat hung here like drapes from the rough walls. “Open water on Mars. Wow.”

“Not really open. The mat flows down, see, and covers this pool. Keeps it from drying out. Saving its resources maybe?”

She scooped out some of the filmy pool water and put it under her hand microscope.

Marc said, “It's just algae, right?”

She did not answer. In the view were small creatures, plain as day.

“My God. There's something swimming around in here. Marc, look at this and tell me I'm not crazy.”

He looked through the scope and blinked. “Martian shrimp?”

She sighed. “Trust you to think of something edible. In a pond this small on Earth there might be fairy shrimp, but these are pretty small. And I don't even know if these are animals.”

She hurried to get some digitals of the stuff. She scooped some up in a sample vial and tucked it into her pack. Her mind was whirling in elation. She studied the tiny swimming things with breathless awe.

So fine and strange—and why the hell did she have to peer at them through a smudged helmet?

They had knobby structures at one end: heads? Maybe, and each with a smaller, light-colored speck. What?

Could Mars life have taken the leap to animals, bridging a huge evolutionary chasm? On the other hand, these could be just mobile algal colonies, like
Volvox
and other pond life on Earth. Whatever they were, she knew they were way beyond microbes. She bent down over the pool again, shone her handbeam at an angle.

The swarm of creatures was much thicker at the edges of the Mars-mat—feeding? Or something else?

She couldn't quite dredge the murky idea from her subconscious. The arrangement with the mat was odd, handy for the “shrimp.” What was the relationship there? Some kind of symbiosis? And how did the swimming forms get to the pool?

She and Marc climbed down from the ledge, playing out cable. As they descended the mist thickened and the walls got slick and they had to take more care. The cable was getting harder to manage, too. She could not stop her mind from spinning with ideas.

On Earth, hydrothermal vent organisms photosynthesized kilometers deep in the ocean, using the dim reddish glow from hot magma. The glow became their energy source. Could some Martian organisms use the mat glow? Wait a minute—

“Marc, did you notice anything peculiar about the shrimp?”

He paused before answering. “Well, I don't know what they should look like. They looked sorta like the shrimp I feed my fish at home.”

“Did you notice their eyes?”

“Uh …”

“The knobby ends, those had lighter specks, remember?”

“Yeah, what about them?”

“So you saw them too.”

“Why, what's the matter—Oh.”

“Right!”

“I see, they shouldn't have eyes.”

“Good for you. I'll make a biologist out of you yet. On Earth, cave-dwelling organisms have lost their eyes. Natural selection forces an organism to justify the cost of producing a complicated structure. You lose ‘em if you don't use ‘em.”

“So if they have eyes—”

“On Earth, we'd say they were recent arrivals from a lighted place, hadn't had time to become blind.”

“But that's impossible. The lighted parts of Mars have been cold and dry for billions of years. Where would they have come from?”

“I agree. So my next choice is that it's not dark enough here to lose the eyes.”

“That glow is pretty dim.”

“To us, maybe. We're creatures from a light-saturated world. Our eyes aren't used to these skimpy intensities. Closest parallel on Earth to these light levels are the hydrothermal vents. There are light-sensitive animals down there, even microbes able to photosynthesize.”

“Maybe they're not even eyes.”

“They're light-sensitive. The critters clustered under the beam from my scope.” “Wow.”

“I need more information, but at the very least it suggests that the glow is permanent. Or at least frequent enough to give some advantage to being able to see. And that means there should be something that can use the glow as an energy source. Maybe the mat is symbiotic—a cooperation between glowing organisms and photosynthesizers?”

“Yeah … That suggests the glow is primary. What's it for?”

“Don't know, just guessing here.”

“Curiouser and curiouser, as Alice said.”

“1 didn't know boys read
Alice in Wonderland.”

“It seems to fit what we're doing.”

“Down the rabbit hole we go, then.”

She gazed down and saw at the very limit of the weak lamplight bigger things. Much bigger. Gray sheets, angular spires, corkscrew formations of pale white that stuck out into the upwelling gases and captured the richness. One spindly, fleshy growth looked like the fingers of a drowned corpse, drifting lazily in the currents …

She shook her head to clear it.
Stay steady, here.

Below the level of the pool ledge twisty side channels worked off at odd angles. These ran more nearly horizontal, and they explored them hurriedly, clumping along until the ceiling got too low. No time to waste crawling back into dead ends, she figured. They headed back to the main channel and then found a broad passage that angled down. It was slick and they had to watch their footing.

The mats here were like curtains, hanging out into the steady stream of vapor from the main shaft of the vent. Some seemed hinged to spread before the billowing vapor gale. She was busy taking samples and had only moments to study the strange, slow sway of these thin membranes, flapping like slow-motion flags.

“Must be maximizing their surface area exposed to the nutrient fog,” she guessed.

“Eerie,” Marc said. “And look how wide they get.”