Serials - parts and parts.

SETI Library: The Mars Mat

Written by Gregory Benford

Illustrated by Lee Kuruganti

Mars. Ruth could still thrill at the wonder of it. Even after a hard week here.

Martian nights came suddenly, a hard black. Now the gloom gave way to a ruby radiance boiling on the horizon. Phobos rose in the west, a lump of white about a third the size of Luna’s disk, moving almost fast enough to see if you watched for a few minutes. If she had the time, she could see it crawl across the sprinkling of stars now fading.

The sudden dawn spread rosy fingers, but she still could see above the growing promise a lustrous blue-white dot. Earthrise. Earth was a resplendent smudge, brimming brighter than Venus. By all rights, blue-white Earth should have been called Ocean, leaving “Earth” to describe Mars. Living on Luna, she had gotten used to the ripe globe hanging in her sky, the continents like scabs of rumpled brown, green and tan, all in a blue immensity.

She peered closely. In the still thin air Ruth could make out the small white point to one side. She had heard that this was the only primary-and-moon visible to the naked eye in the solar system, but the sight still stunned. Until a few centuries ago, that tiny little interval had encompassed humanity’s reach. On the bigger creamy-blue dot, a million years of hominid drama had played out, blood and dreams acted out on a stage a few miles thick, under a blanket of thick air.

“Ruth! Hook up your following lines,” Alex Zuminski’s rough tones came over comm.

She hurried to the top of the open-sided elevator, loping in the light grav. She was still getting used to the long, lazy strides she could use here. The team of five made room for her and she patched her power and aux air lines into the elevator wall. If they got stuck, the elevator itself could sustain them for days. She had found the fact that such precautions were routine a bit unsettling.

Zuminski gave her a sour glance, and then went back to giving orders and coordinating with the Descent Base Control.

The rising sun stretched sharp shadows everywhere. She knew the team, but where was . . . ? There. Akralan’s square frame stood against the back elevator wall, impassive. Through the bubble helmet she could see the alien’s shadowy skin, his eyes like rectangles with rounded corners. His nose was a large protruding cone high on the forehead. He stood without movement in his custom pressure suit, like a human though considerably larger.

He seemed tense, but she had learned that reading the facial signals of the hominid-like alien was difficult. Worse, it could be misleading. She kept thinking she understood Akralan’s motives and goals, and kept being proved wrong.

He had put her through so much already, all to coax secrets from this alien. Ruth could barely believe she was off on another stunt, far from the quiet studies she loved. SETI messages were her life’s work, but not Akralan’s. It—or he, perhaps—was an alien who liked action, immersion in life’s possibilities. She had learned a lot since she had plunged a hundred kilometers from orbit with this odd daredevil. That, plus many days spent slogging through SETI text, deciphering them with him, had made Akralan seem understandable. Quite plausibly that was an error. Akralan was quite good at giving nothing away that it did not want to.

“Beginning down,” Zuminski called. The big man peered around at Ruth and scowled.

On the way to the vent, a crew member had described Zuminski as a “spherical bastard”—always a malcontent, seen from any angle, incessantly hectoring his team for better performance. Zuminski seemed to treat visitors as intruders, sources of chaos. Ruth didn’t mind; in fact the man was rather appealing in his rough-diamond way. If he kept his team on alert, all the better. He glanced at her again. Probably horny, that’s all. She smiled at him, mixing in a sardonic wink. He looked startled, then scowled even more. Good. Might as well have some fun while facing the unknown.

The elevator floor hummed and the landscape rose as she watched. A dust devil churned across the dunes to the north. She could still see stars in the high bowl of the sky. No sense yearning here for green hills or ocean swells. It seemed an ideal place to send trainee saints, to get a look at what was coming to them.

Mars held a subtle but varied palette, its tans and rosy shades fraught with meaning. The mind adapted. Even so, iron oxides were a limited medium for nature’s work. They descended into the lit vent below. The first thing she noticed on the vent wall was a small glimmering patch. Pure water ice was improbable on the Martian surface, since it would sublime away quickly. But the light orange film on the edges of the rocks near the hole glistened. A brown scum clung to it, keeping the fragile fluids sealed inside. An appetizer for the wealth below.

Not, on the face of it, a place where a librarian would ever venture.

****

It had been hard convincing the SETI Library’s Prefect.

“There is quite enough to do here at the Library. Why—” The Prefect raised an eyebrow. “—should I authorize a long trip—to Mars!—on such an unlikely possibility as this?”

She had expected such a question, but her answer had little force unless she prepared him for it. “You’re quite familiar that the Mars mats deep below the surface have some symbolic ability.”

“Of course.” The Prefect’s unreadable face was as stony as the even tones of his neutral sentences. “But others have studied that extensively.”

“We got new information from Akralan. He says his civilization—or maybe another, from whom they inherited; it’s hard to tell in the translation—they came to Mars long ago.”

“How is that relevant to our mission?” His disdainful gaze was now also puzzled, at least.

Very well then, time to be more assertive. “Akralan will give us a symbol-set that the Mars mat may recognize. He says it’s over a million years old.”

This took the Prefect’s angular face by surprise, though he quickly covered by pursing his leathery mouth.

Ruth felt a burst of pleasure. It wasn’t easy, startling the Prefect—that was part of his aura.

A SETI librarian had to always remember that people think in very narrow time scales. Bureaucrats like the Prefect usually did not. Earth truly lived in the boondocks—physically, and as became apparent, conceptually as well. As if in silent salute, the Prefect raised his eyebrows but said nothing.

“Mars had intermittent wet and warm eras. Its Mars mat life developed for well over billions of years, bursting out onto the surface in the good times, cowering below in the bad. For a very long time now, the bad has prevailed.”

The Prefect’s scowl did not go away, but deepened. “So you believe, given what Akralan says, that occasional galactic travelers might have left some deep memory in the strange Mars mat culture?”

She plunged forward. “Yes, I do. In a way, this is like SETI messages. We know that some could date back billions of years. This one just isn’t in microwaves.”

The Library was mostly about its cryptology abilities, because deciphering the SETI messages was more like puzzle solving than archeology.

He looked worried. “This would distract you from your duties.”

As if falling from orbit, ascending Everest, and diving to the floor of the ocean didn’t . . . “I can do plenty of Library work while on the Mars Cycler.”

The Prefect gave her a pensive stare, and then nodded. “Very well. I will find room for this in our budget. Somehow. Be careful.”

Walking away from the interview, past the curious glances of the Prefect’s staff, she wondered what could be lurking deep within Mars. Some of the ancient SETI messages showed a common, deep motivation. Their antique societies, feeling energies ebb, yet treasuring their trove of accumulated art, wisdom and insight, wanted to pass this on. Not merely by leaving it in a vast museum somewhere, hoping some younger species might come calling someday. Instead, many built robotic funeral pyres fed by their star’s energies, blaring out electromagnetic elegies of their timeless majesty.

Akralan implied that someone, perhaps his own kind, thought it more likely that intelligence would arise on Mars. What would such visitors leave behind there?

Then the thoughts that always arose when she was about to embark on another risky adventure with the alien, Akralan. Was she really up to this?

****

The boxy elevator was slow and elaborately buffered, carefully engineered to not damage the life clinging to the rock nearby. Ruth watched the Descent Team, as the crew that regularly carried out these missions called themselves, talking earnestly on private comm. Some chuckled; no doubt they were gossiping about the newbies, her SETI Library team. Only to her, Akralan and the interpreter, Xiaoling, was this rattling descent new.

Making a vent excursion was now well defined but rigorous, its methods honed by many decades. This clattering open-sided elevator carrying Ruth and the team had been a big news bonanza a century ago. Seismology had probed this region with artfully placed explosions, mapping ice layers several tens of meters below, plus some enticing tendrils that might be lava tubes. Then smack in the middle of the territory they found this yawning hole forty meters across. A volcanic blowout crater, its lip of rock blurred by the constantly shifting sands of Mars. The key to life here.

Alex Zuminski looked over at her and sent on single comm, “You will follow orders strictly here. At all times.”

“Of course,” she shot back—mildly, using soft tones, though she was not feeling that way.

The descent team around her was seasoned. Routines had their own momentum. They had followed a strict schedule that morning: No dallying over breakfast, though the hard cold that came through the rover walls made her shiver. As the elevator swept past rock, she peered out through her helmet and munched a quick-heat breakfast bar. Her helmet gave her the chance of eating a whole tube of beef-flavored toothpaste, too, but she ignored that option. They would run on in-suit rations today, all day. No returning to the Spartan comforts of the rover that had lumbered here over rugged terrain.

Though thin, the Martian carbon dioxide atmosphere mustered up a breeze from below as they descended. A fog bank formed near a side channel, vapor escaping from the wealth below. As they went past it the ivory mist loomed like a cliff of misty, translucent rock, the edges marbled with blues and greens. This was the first she had seen of any moisture. The Martian atmosphere was an infinite sponge.

She glanced up as the sunlight faded. The open elevator shaft stretched into infinity above and below, with lamps spotted along it. Even so, a circle above was a bowl of sharp stars. After months in their spare transport from Earth to Mars, she found that humanity’s Euclidean rigidities made nature’s irregularities beguiling. Even red-brown plains were better than a life of unending rooms.

Then came color on the rock walls. They rumbled slowly down through an unfolding underground ecology—splashes of grays, lime greens, purples. Gray mist boiled from below. White crusts coated nearby rocks. Life.

On Earth, over a billion years ago, anaerobes went underground or underwater to get away from the poisonous oxygen atmosphere. They thrived in the most hostile niches like hot springs and coal mines. In that infertile ground they survived, but remained as microbes, developing few larger structures. Still, they prospered—life that didn’t use oxygen still had more mass on Earth than the life that did. The anaerobes lived underground or near the deep ocean thermal vents that she had visited with Akralan. But here on Mars they flourished.

Martian anaerobes had to fight the gathering cold and drought here, so billions of years ago they had followed the heat and gone underground. They might even have been more advanced than the Earth anaerobes, and they certainly were now. Somehow they had taken advantage of the dark, warm planetary interior, when they had to retreat as the carbon dioxide atmosphere bled away into space and the hammering ultraviolet came storming in. Adversity had benefited them

There were Earthly deserts that went without rain for years, like the Namib and the coast of Baja California. Plants and animals living there had to trap the fog to get water. The Martian vent system was like those—the wettest environment on this planet, while resembling the driest on Earth.

Akralan asked his translator something and Ruth caught its gesture. She fumbled at her waist pack for a thermal probe, switched it to readout mode. “Minus fourteen C, not bad.”

She glanced at Akralan, who was peering ahead. The alien had a rapt look on his lined face, eyes stilled with wonder. Ruth had begun to think of this alien as a man, though they did not even know its sex. Somehow, Akralan seemed like a man, in his expansive gestures and direct attitudes, not at all like a woman. Ruth herself oscillated between seeing the alien as genuinely alien, and so unknown, versus viewing him as a kind of male she had never met. This unsettled her more than she cared to think about.

She knew it was a mistake to believe that humans could read alien expressions, too, but in time she had learned something of Akralan’s fleeting expressions. Quick flashes of the pale green eyes, peculiar puckering in the wide lips of its brown mouth, the slow gravel hiss as he spoke.

This same look of intent focus—respect?—she had seen come over Akralan before, when they visited the black smokers off the California coast. The sulfur-based life at the hydrothermal vents had excited Akralan. Meter-long tube worms and ghostly white crabs had reminded the alien of his own world. On that shallow ocean planet, life forms harvested the bacteria, which in turn lived on chemical energy around warm volcanic upwellings. The vent communities on earth were islands amid the inexorable cold and dark of the ocean bottom.

They rattled downward, headed for a kilometer depth. In the next fifty meters the scum thickened and the brown filmy growth glistened beneath her headlamp as she studied it.

“Mars mat,” she sent on comm to the translator, a slight woman who never left Akralan’s side. “Like the algal mats on Earth, a couple of billion years ago.”

The woman nodded and in a moment relayed Akralan’s reply. “The cradle of life.”

With that, Akralan began chanting. The rumbling tones were just like its performance when they had visited a black smoker—a deep bass note reverberating in the chest, building harmonics into a strange wail.

The Descent Team backed away from the alien. They had been disciplined so far, treating Akralan as just another visitor, though she knew they were deeply interested. Now their mask of indifference fell away. They looked alarmed, mouths open, eyes wide.

Ruth tried not to show her own unease. Remain cool, she thought. Especially if you’re risking your neck deep in a gloomy hole on an alien world. Even if you are, after all, a librarian. . . .

Unlike their black smoker visit, this time Akralan did not try to dance. It finished its chant with a booming call and fell silent. The ceremony, paying tribute to what Akralan had called in the Pacific Ocean its ‘legendary ancestral origins,’ tapered away in a long bass note.

But Zuminski was livid. “No unnecessary talk!” he cried. “Or movement!”

A stiff silence. The elevator eased to a stop in a wide bay, the floor humming beneath their boots. She could barely make out the dimensions of the place from the small suit glows of the crew. Zuminski called, “Forward. Assemble at the right wall.”

The gate opened and they shuffled out. In the gloom Ruth gazed around. Long spires of dirty gray jutted from the ceiling. They came to tapered points like lances.

Ruth asked with a gesture, “What are—?”

Zuminski kept walking ahead and curtly said, “Are colonies. Shaped around stalactites. Mostly bacteria. Hang from walls and ceiling. Bigger here than on Earth. Call snottities.”

He was so used to lecturing tourists he just shot out phrases. She said, “Snottities? The name—”

“Like snot from nose, see?” He slapped one as he passed it. “But have rock too. Hard.”

She reached out to touch one and he said, “No! Some has hydrogen sulfide. Like battery acid, eat gloves.”

“But you—”

Zuminski grinned and held up his gloves. “I have special. Not eat.”

She edged away from the walls. Zuminski said, “Not big danger. Keep your eyes open. Much to see.”

She nodded and shut up. The mat was thicker here, and . . . there—she felt a chilly surprise. All around them, 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 Mars mat itself was softly lighting up. Tapestries of dim gray luminosity reminded her of things she had only heard about—will-o-the-wisps in old graveyards, foxfire on old wooden sailing ships...

She felt something chilling. Not fear, precisely, though there was that. Something with wonder in it: awe.

Navigating by the light of the walls was like hiking by moonlight. Ruth shortened her Marswalk stride.

“How can it do that?” Xiaoling whispered on the Library team comm.

Maybe she hadn’t taken time to read up? Tending to Akralan was job enough, Ruth guessed. Xiaoling seldom looked other than tired, and Ruth could only guess at the strain of always dealing with an alien mind. “Their greeting, I guess,” Ruth said.

Zuminski gestured and arc lights came on, discreetly focused on cave walls away from the first large pieces of Mars mat she had seen. The lamps cast luminous fingers. Zuminski followed the beams, leading the descent team into a dim, high-arched cave. The Library team followed behind, still getting their bearings among the looming mats. Once into the cavern they moved forward into inky nothing, passing by the increasingly lush mat. Some phosphoresced in pale blue and ivory. Others had fans like elephant ears, apparently to catch moisture.

She caught fragments of the Descent Team comm, short all-team notes. “"It’s misting pretty heavily.” “Watch for that new sprout.” “Plenty wind now.” Ruth watched coils of speckled moisture rise past them.

Plants and animals regulated Earth’s whole atmosphere and climate, Ruth recalled, and this Mars mat did something similar. The top of the linked Mat community was always drying out and getting cold, so the Mat sent streamers up to its besieged parts.

“Forward, keep file,” Zuminski sent.

Further into a high, arched cavern they went. A raised walkway kept them off the oatmeal-colored Mars mat flooring.

Zuminski gestured. “All suit lamps off. Let eyes adjust.” Lamps quenched, the gloomy grotto came alive with shimmering luminescence: bursts of gold, dapplings of orange, vermilion splashes that laced through turquoise filigree.

“This mat is a complex structure,” Ruth said to Xiaoling. “Tell Akralan these are root-like filaments, thick petals, moss, lichen... But like a higher plant in level of complexity and organization.”

Akralan spoke in his rough notes and Xiaoling translated, “All this, even though it’s just a mixed community of microbes?”

Ruth gestured to thick filaments like ropes of blue linguine. “Remember the giant tube worms around the black smokers? These seem similar.”

Akralan spoke and Xiaoling said, “Similar shape again.”

“Right.” Ruth knew that it was still unclear whether Mars had colonized Earth with microbes, far back in the early eras of the solar system. Tubular forms certainly did not alone imply a common origin. She was no biologist, but she knew that; did Akralan?

Zuminski stopped in the murk ahead. “Profile forming,” he whispered over comm.

Ruth and Akralan worked their way around to see.

Xiaoling said, “What the hell?”

Ruth watched “A mimicking image.”

“How, how can that be...”

Didn’t Xiaoling prepare for this? “Parrots imitate sounds. This mat imitates patterns imposed on it. The first expedition found that response. The mat learned to signal with shapes. But why?”

Xiaoling’s slow voice was baffled. “Learned?”

“Echoed, at least. Showing that it sees us.”

“It’s communicating with . . . ”

Zuminski came on comm—impatiently, she could tell, from his stretched voice, tight and controlled. “It is a biological pictograph. I have no clear idea why. No one here does, in the people who work with this every day. But it is better if we do not talk.”

Ruth thought of saying, But after all, it can hardly talk, can it? I—and then realized she was being stupid, had completely misjudged the tone, and—that she had completely failed to understand this man. He was focused not on controlling his Descent Team, but in the problem before him. And he could not solve it.

Luminescence brimmed in the gloom. A spaghetti swarm of pale blue strands was lacing through the dark mat, stretching and expanding like tendons in some strange muscle that rose just fast enough for her to see the change. It was a few meters away, she judged.

She felt around carefully with her feet to get the level right, to be sure that in this low gravity she did not have the sense of slowly rotating. Gravity was subtle. You thought you had your balance, a thing you had learned as a child, and now it was a fresh problem.

So was