The Sunborn (6 page)

“Hey, I’m not a geophysicist,” Julia said, throwing up her hands.

“It doesn’t make sense to me, either,” Uchida said. “Using the magma model”—he nodded to Julia with, it seemed to her, totally unnecessary diffidence—“these waves would come from fluid movements of the magma in constricted passages.”

He and Viktor got into an extended technical discussion.

Julia turned to the big port view bubble and relaxed, preparing herself for the coming descent, and watched a new vista unfold. Crystalline strata sparkled with diamondlike facets in the hard sunlight. Sullen lava flows were as dull as asphalt in spots, and in others where the dust had worn them, shiny as black glass. And everywhere, reds and pinks in endless profusion, myriad shades depending on composition, time of day, and angle of sunlight. The crater cliffs began as brooding maroon ramparts at dawn, then lightened to crimson at noon and slid into blood red in the afternoon’s slanting rays.

Ayers Rock cm Mars. I went so far away and found myself still at home.

In the red twilights of the long years here she had recalled her girlhood in Australia. Not the rural summers with relatives north of Adelaide, with their droughts, brush fires, and smelly sheep, no. Nor the flies and hard work. Instead, the wide skies and wildlife returned to her in memory. The eucalyptus trees were beautiful and endlessly varied, with names like rose-of-the-West, yellow jacket, jarrah, Red River gum, half mahogany, grey ironbark, and especially the ghost gum, which she soon learned was
Eucalyptus papuana,
appearing in its silvery grace on postage stamps, calendars, and tea towels. They framed the human world of tea-colored, dammed-up ponds, of hot paddocks of milling sheep, of rusting, corrugated sheds tilted into trapezoids—trees standing as silent sentinels at sunset, glowing like aluminum in the settling quiet.

On impulse she had ordered a didgeridoo, the ancient echoing instrument of the Aborigines. It came at her personal expense in their fourth shipment—at nearly a million dollars, but they were rich in what Viktor called pseudomoney, from the book and interview rights; though Axelrod seemed to get most of it. The slender tube was labeled in the manifest a “wood trumpet,” but it sounded nothing like that.

Some Aboriginals had complained that women were not allowed to play didgeridoos in their culture, that she was showing disrespect, but when worldwide sales of didgeridoos and concert tickets rocketed, they fell silent. She learned the trick of holding air in her bulging cheeks and breathing it out while her lungs drew air in, so that she could maintain a long, hollow tone. The skill was unique; normally people never needed to speak while they breathed. The long, low notes fit into her memory of the great Australian deserts, and when she played, the notes somehow sang also of red Mars.

Watching Gusev Crater through the wall screens—which improved in resolution and size with every upgrade, so that these days it was as though they had a bay window in each hab room—and playing the didgeridoo, called forth her sense of bleak oblivion. The spareness of deserts had always made her mind roam freely. She could find fresh perspectives on her field biology that way, and in those years had made her reputation as the central authority on the Marsmat. Labs Earthside worked at her behest, comparing Marsmat DNA to Earthly forms.

Somehow in her mind her girlhood and Mars blended. She had come to see biology as the frame of the world in those girlish years—the whole theater, in which vain humans were only actors. Mars confirmed this. On Earth, knowing biology quietly brought order to the ragtag rustling of people, ensured that their lives had continuity with the hushed natural world.

Just as it could to Mars. On that article of faith she had built their years here together.

Over a rise and there ahead the Vent R opening yawned, faint sulfur stains spreading from its mouth. The sharp ridges framing this canyon could not dispel the sensation of spacious wealth. Satellite observations had first detected vapor here, then found hints of vent chemicals. Sure enough, the lambent light glowed through an early morning fog before them. Iron-dark stains mingled near the vent splashes of yellow and orange. Red slopes nearby rose up and darkened to cobalt, then into indigo. Evidence of other ventings, long ago?

A dust devil in the distance wrote a filigree path across the rusty plains. She had always wanted to somehow sense their sandstorm sting and the moist kiss of the dawn fogs. All this time, and she had never felt Mars on her skin.
Not quite.
Then she recalled the hard days of the second year here, just before the first return launch—which she and Viktor declined. There had been one emergency, when she had been forced to run from their first, collapsing greenhouse—headed for the hab’s lock in a stretching minute of panic that she would never forget. Raw Mars, sucking at her lungs, drying her skin—

“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 CO
₂
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 CO
₂
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 slime, 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.