Marsquake! (7 page)

And even though Sean hadn’t really been paying attention, he said, “Tap the person next to me three times on the arm, one tap, pause, then two quick ones.” The response was almost automatic, because it had been drummed into everyone in the colony over and over, one of the basic safety rules for anyone working outside.

Ellman was the kind of teacher who always seemed nearly as offended by a correct answer as by a wrong one. For a long moment he stood staring at Sean, and Sean could see the man’s scowl behind the faceplate of his helmet. At last Ellman, sounding displeased, snapped, “Everyone remember that. Now check your equipment.”

Jenny obediently opened her waist pouch and took out the miniaturized digital camera. It would record up to ten thousand images and even movies—record them and also transmit them to a receiver that
Ellman carried in his backpack, where backup copies would be made, just in case. She ran through the checklist to make sure the camera was working properly, and Sean supposed he had better do the same with his own equipment. His camera was fine. His suit lights were fine. Oxygen level, suit heater, everything was working just as it should. He was beginning to feel strangely eager and strangely anxious. Were they ever going to get their turn?

Team eight had finally vanished, all of them now under the surface. Ellman stepped to the dome, looked inside, and called off six names, one of them Pavel Rormer. “Pavel will assemble you under the surface,” he said. “Follow his instructions until I arrive. First group, go.”

Jenny and Sean shuffled to a different position until they could see the six team members file inside the dome. The lift was very primitive, an open cage of a compartment, suspended by a cable. Rormer turned, gave a thumbs-up signal, and pressed the button that lowered the lift. The cable paid out from its drum, and the group sank out of sight, leaving just
the rectangular, dark opening leading far down into the planet’s surface. No sound came from the winch or the elevator. The Martian atmosphere was too thin to let much sound come through, and it was always a little odd watching things happen in silence.

Minutes crawled by on hands and knees, and then the lift came up empty. Another group of six went down. Jenny nudged Sean and mouthed, “Bet we’ll be last.”

They were indeed in the last group. Ellman joined them in the lift compartment, and everyone had to crowd together—six could fit fairly well, but seven was a real squeeze. The leader of team ten was standing at the dome opening. Ellman waved to him, pushed the button, and the winch turned.

Now, Sean could faintly hear the grinding of the gears. It was transmitted not through the air, but down the cable, into the lift compartment, and up through Sean’s feet. The ride was not at all comfortable with the lift swaying and creaking, but it was interesting. The walls of the shaft were rock—Martian bedrock. The upper layers were a deep gray,
peppered with many small cavities, like a slice of swiss cheese. Gas bubbles, Sean supposed. They had formed when the rock was liquid, and when the lava hardened, the gas had left these little pockets behind. Areologists loved those petrified bubbles because they preserved the ancient Martian atmosphere, an atmosphere that had been much richer in oxygen and other gases than the present-day Martian air.

Then the walls became smoother and darker with a glistening surface that looked like glass. That was what happened when silica melted and rehardened. They were riding down through a patch of rock that, in the remote past, had been sand, melted by the sheer heat of an eruption.

Deeper and deeper, and the rock continually changed in texture and color. Finally Ellman slowed their rate of descent. The lift settled into an underground opening, and now it was inside a man-made cage of girders, guiding it even farther down. Sean had expected it, but he still drew in a sharp breath.

They had broken out into an underground cathedral, an immense pocket far beneath the surface. He
swallowed hard. The first marsquake had resulted from the collapse of a chamber very much like this one. Tons of rock falling, burying everything for eternity. No wonder Mickey had—

Get a grip, Sean told himself.

They dropped nearly fifty meters until they came to the bottom. The lift cage slowed and slowed, then stopped with a bump, causing everyone to stumble. Sean’s helmet radio crackled with relieved laughter, and he realized he was not the only nervous member of the team. Ellman’s voice ordered, “Everyone out, please. Orderly, but hurry. We have things to do.”

Sean left with the others, joining the group already assembled at the far side of this great cavern. He could see stacks of equipment there, tents and rations ferried down days before by the advance team, ready for the explorers to pick up. They would camp out for several days of exploration, camp out far beneath the surface of Mars.

He felt a light tap on his shoulder and turned. Jenny had her camera out. She pointed, and then she took a picture of the empty elevator cage as it rattled
its way back up through the girders, back toward the black opening far, far overhead in the smooth arched ceiling, barely visible even with the glare of work lights coming up from the chamber floor.

Sean watched her. Once again he felt just a flutter of the kind of panic that had seized Mickey as the lift cage vanished into its shaft.

There went the last, the only link to the surface. What if he never saw it again?

“Doe, Laslo, any time you two are ready!” Ellman’s sharp voice sounded in his ear.

Jenny made a face at Sean. He gave her a grin in return and hoped it didn’t look as sickly as it felt. Then they turned their backs on their lifeline to the surface and hurried over to join the team.

From the huge cathedral-like
opening, oversized lava tubes branched off in six different directions. Team nine drew for the middle tube leading south
from the chamber, and their assignment was to follow it, map it, and explore it as far as they could over the span of eleven days.

The tunnel slanted downward at a steeper angle than any of the others. The first few kilometers had already been checked out by the pathfinder crew, so for the first day, the explorers made good time. Jenny kept checking her wrist data recorder as if fascinated. At one point she nudged Sean and tilted her arm so he could see the readout. At first he didn’t understand the number, but then it registered: D/S -1.202k. The “D/S” meant “distance to surface.” The default setting for all of the recorders was the elevation at the entrance to the lift shaft, the equivalent of sea level back on Earth. The -1.202k figure meant they were now more than a kilometer beneath the surface of Mars.

Sean kept photographing the walls of the lava tube. They were fairly smooth with great stripes of color in them, sometimes horizontal, sometimes vertical. He didn’t know what kind of minerals these were, but his job was just to record as much variation as he
could, so he clicked away. At the end of several hours’ march, they were in unexplored territory. Evangeline Watts, one of Chris Wu’s apprentices, halted their progress every few hundred meters to take seismology readings. These showed strain patterns and indicated whether or not the tube was structurally sound. So far, all indications were good. They kept moving.

They soon came to a very weird patch. The lava tube was still huge, larger by far than the one they had practiced in. The arched ceiling overhead was more than twenty meters up, and the thirty explorers could easily spread out across the rounded floor, marching along abreast of one another if they wanted to.

In fact, they were walking in a long, straggling group, leaning back as if they were traveling down a steep hillside. Experts in rock formation were taking samples, atmospheric scientists were getting excited because the atmosphere was thicker and richer here than on the surface, and physicists were clustered in small groups animatedly arguing over the forces that
left this huge tunnel system. Jenny and Sean were near the rear of the group, pausing to record everything in images. Sean didn’t notice how everyone ahead was clumping together until Jenny asked, “What’s up?”

“Come and see,” someone responded.

They hurried ahead. Sean stepped around the crowd and gawked. The tunnel ahead looked as if it had been transformed into a fairyland cavern lined with jewels.

Or so it seemed. Sean raised his camera and began to take pictures. In the camera viewfinder a million colors sparkled back at him—reds, golds, greens, blues, all the colors of the spectrum, fragmented and glittering in the lights from the explorers’ helmets. And the floor of the tunnel had changed too. Not rock here, but … sand? A fine red sand? That’s what it looked like.

“Over here! Quick, photographers! Over here!”

“Where?” Jenny asked.

A kneeling figure over on the far side waved an impatient arm, and the others made way as Sean and
Jenny hurried over to him. “Who is it?” Sean asked.

“Me, Ted Miles.” Miles was one of the biologists of the colony, and Sean knew that he was also one of Jenny’s tutors.

“What have you found?” Jenny asked.

“Dr. Ellman, permission to go private channel.”

“Go ahead, Miles.”

“Band one, you two.”

Sean adjusted his helmet radio, and Jenny did the same. “Got it,” she said.

“You receiving me okay?” Miles asked.

“Roger that,” Sean said, wondering what the secrecy was all about, and Jenny said, “Yes.”

Sean could see now that Miles’s gloved hand held a short, soft brush as delicate as a tuft of fur. He was still kneeling, and now he leaned forward and brushed the sand, grain by grain almost. “Look at this.”

Sean leaned forward. He could see a pitted surface, sand that had somehow compacted. In it, smaller than his little fingernail, lay a curled, spiky
something
—the same reddish color as the sand. It looked almost like the backbone of a tiny snake, coiled up and colored to
exactly match its surroundings. “What is it?”

“A fossil,” Miles said, his voice sounding almost reverent. “I’m sure of it. A multicellular fossil.” He chuckled. “I could be the most famous biologist on Earth right now, if we could let Earth know. People have searched for these for decades. I couldn’t believe it at first—”

Sean became aware that others were crowding close. A stocky figure—Ellman, because Sean could make out the yellow bands on his arms—gestured them back. Jenny knelt close to Miles and leaned forward to shoot a picture.

“Go stereo and get in close, Jenny,” Miles told her. “Macro for as much detail as you can get. Let me provide the lighting to give as much relief as we can get in the stereo pics. You—”

“Sean Doe.”

“You, Sean, please back off and get shots of the surroundings—the sand, the position of the fossil in relation to the tunnel wall, everything.”

Sean shot several pictures before Dr. Ellman broke
in impatiently, his voice sounding irritable in the helmet speakers: “This is all very good, but would you care to tell the rest of us what’s so interesting?”

“I found a fossil, Dr. Ellman,” Miles responded. “This whole part of the tube was flooded with water at one time. This soft sandstone is sediment—the edge of an underground sea.” The scientist gestured at the walls. “All this is mineral formation that comes with the slow leaching of water through the levels above us. Things lived here once. Multicellular creatures. I’m not sure whether this is a skeletal system or an exoskeleton, because it’s so small it’s hard to see clearly, but—”

“Take it and let’s get moving,” Ellman said impatiently.

“No, impossible. It’s far too fragile for me to try to extract it with the tools I have with me. I’m going to mark the location, though, so we can come back properly equipped and get this one.” Miles took out a tube about the size of a pen and clicked it. He lay this across the sand a few inches away from the
coiled thing with extreme care. “Yes, just look at the fine detail. It’s too delicate for me to risk removing it right now. I’ll return with trained personnel later. Okay, Sean, Jenny, switch back to main band.”

In a few words, Miles spoke to the whole group and explained what he had found. No one seemed very excited, and Jenny said impatiently, “This is like the Holy Grail of paleontology, everybody! The only other indications of Martian life have been microscopic, ancient fossils that may or may not have come from bacteria!”

“Everyone look down,” Miles pleaded. “There may be more. As we continue, please, everyone look down at your feet.”

The sandstone proved to be brittle and, as Miles called it, frangible. When groups of people stopped close together, the surface fractured, like thin ice on a pond. Miles pled with them to spread out more—who knew what frail little fossils might be broken to pieces by a careless foot?

But Sean couldn’t constantly stare at his boots. Not
when the tunnel walls offered so much color, so many jewel-like shimmers of light. It was like the cave in the old story of Ali Baba, he thought.

The one where a powerful evil genie guarded the riches …

Days passed, and at
a steady, determined pace, the exploration team went deeper and deeper beneath the surface of Mars. To Ellman’s disappointment, the lava tube gradually curved to the west, away from the colony. It would not be usable as a place of retreat. Not that it mattered as Jenny pointed out; by now they were so far down that no drill from Marsport could have reached them.

The lava tube fed in and out of larger openings in the stone, caverns that seemed to have been formed by water action. They certainly didn’t have the characteristics of magma chambers but showed evidence of erosion, sedimentation, and crystallization, all characteristics of a water-rich environment. Now and then they found loose patches of the fine pale sand, but most often it had hardened into the brittle, easily broken sandstone.

Oddly they found no more fossils. The level of fossilized sand in the tube had gradually risen—now the lava tube was half choked with deep layers of the fine tawny red sandstone, and the patterns on the walls showed more multicolored crystals of ancient salts, remnants of the underground sea that once had filled the ancient tunnel. At the base of the walls, where once the dwindling water had lapped, a thick crust of white crystals now marked the boundary. Nothing unworldly about the crystalline substance, though. It was sodium chloride, NaCl, good old table salt, just the same as on Earth.