Marsquake! (8 page)

“The saline level down here must have been extraordinary,” Jenny said in her serious biology-student voice when they had encamped. She and Sean were inside one of the tents, eating a not very tasty meal of expedition rations, sipping at their water containers to wash the rations down. Jenny munched without seeming to pay attention to the taste. “The deeper we go, the brinier the water would have been. At the end, as the sea was drying up, the water must have been supersaturated with salt. Nothing could have lived in it.”

“Nothing …
human,
” Sean said with a horror-movie leer. He added a spooky laugh: “Mwah-hah-hah!”

“Okay,” Jenny said with a grin. “So maybe salt-eating Martian monsters lived in it. But they would have been a centimeter or two long, and you probably wouldn’t have recognized them as even being alive.”

Sean bit into a cracker that was supposed to contain protein, vitamins, and minerals. It tasted like it contained cardboard, sawdust, and grit. He made a face. “This stuff is awful.”

Jenny stared at the bar she had almost finished eating. “Yeah, the food isn’t great, but at least it keeps you going.”

“Right. Just the thought that whenever we stop, we have to eat this junk makes me want to keep on going forever.” Sean bit off a corner of his bar and tried to ignore the flavor. “Miles is going cracked trying to find more fossils,” he said. “That was really bizarre, that one fossil being there and then nothing else.”

Jenny took a drink of water. “Not so bizarre. First, remember that fossilization is extremely hit or miss. Fewer than one percent of all animals that are buried
become fossils, even on Earth. Conditions have to be just right. Then, too, remember the location of the fossil. We were probably standing right on the beach of the underground sea. Millions and millions of years ago that little critter came swimming up to mate or to spawn or something, and it died. That happens on Earth a lot, you know: Sea creatures creep up onto land to lay eggs, like the extinct green sea turtle, or to mate, like the grunion.”

“The what?”

“It’s a fish! Honestly.” Jenny never quite understood that not everyone was as interested in biology as she was. She shrugged. “Anyway, sea creatures coming up onto the beach is a common pattern on Earth. Might be the same on Mars. Could be that most of the fossils would be on the edges of the water, not in the depths.”

Sean said, “Depths is right. Have you noticed the air pressure down here? We could walk around with our suits off.”

“Except we wouldn’t be able to breathe. The pressure’s almost the same as near the top of Mount Everest
on Earth—but it’s all CO2. You’d be able to take about five breaths of that before you asphyxiated.”

“We turn back tomorrow,” Sean said. “I think Miles would like to stay behind, to tell you the truth. He’s still wanting to find more of his bony little buddies.”

“He can come back later with his team,” Jenny said. She sniffed, taking a bigger bite of her ration bar than Sean ever dared to take of his own. “You know, Pavel Rormer’s doing better than I expected.”

Sean made a so-what gesture. “He’s got atmospheric testing to interest him. As long as he’s occupied, he’s not spouting nonsense. I don’t see him going out of his way to be chummy with anyone else, though.”

“No, he’s not friendly with anybody. But at least he’s not fighting.”

Though neither of them commented on it, more than the pressure was rising. The air temperature was heading up too. On the surface, even at noon the thermometer never registered more than ten below zero during the winter. In the lava tunnel, warmth increased as the exploration team went farther below
the surface, until it leveled off at 14.6 degrees Celsius—the temperature of a cool spring day on Earth, but very balmy for Mars, and well above freezing. That brought a bit of a disadvantage though, because while the pressure suits could be heated to counteract the surface cold, they had a harder time dissipating the heat buildup. Sean thought that sometimes it felt as if he were working in a sauna, a portable sauna that he carried around with him.

Still, the expedition was going well. Everyone was busy, Sean reflected the next day, and no one was fighting. That was the key. By this point everyone in the expedition was laden down with samples of minerals. Sean was grateful that all he and Jenny were taking was their series of pictures—and they didn’t weigh anything.

For about the third or fourth time in their journey, they came into yet another enormous open chamber, this one more than a hundred meters from floor to ceiling. Powerful lights cutting through the gloom showed that the cavern’s upper reaches dripped with
stalactites—long, pointed fingers of varicolored stone. As the water levels had dropped, these had been formed by mineral-rich water seeping down from the far distant surface. Each oozing water droplet had evaporated, leaving behind a minute trace of the minerals it carried, and so the stalactites had grown, a molecular layer at a time. Some of them now were ten meters long, great stone daggers pointing downward. Sean had a dizzy kind of feeling: looking up at the stalactites was a bit like hovering in the air above some ancient medieval cathedral on Earth and looking down at its spires.

The sand underfoot lay in a strange, gently rippled pattern. No waves should have disturbed the underground sea—no winds ever blew down here to stir them up. Still, somehow the water had flowed, and it had left behind graceful traces of its passage. Here, as in many stretches of the tunnel, the sand had hardened, cemented into place by the minerals that the drying sea had left behind. It was sandstone now, extraordinarily fine grained, looking as if you could stir it with a toe. Miles was edging around the cavern’s
periphery, his eyes keen on the sand underfoot. Sean knew that he dearly wanted to find a second fossil, and he wished the man luck.

“This is odd,” Jenny said. They had switched to a private frequency to talk about the photos they were recording, though their helmet receivers were set to pick up the main frequency in case someone called them. Sean shuffled over to see what she meant.

She had found a small branch tunnel opening. It didn’t look like a lava tube though. More like a cave cut by running water. The opening was only about three meters tall, and it had a different shape from the oval lava tubes. This tunnel’s cross-section had the shape of a spade in a deck of cards: sharp top, almost a crevice, but a fairly broad body.

Jenny squeezed through the opening, and Sean followed. “Don’t go far,” he warned her. “Ellman will notice if we’re away for a long time.”

“I’m just taking some pictures.” Her camera snapped four or five times. The passage opened up slightly as they explored it, though Sean thought that Mickey would have collapsed from claustrophobia a
step or two into this confining space. He felt the surface underfoot shifting. “Back on sand again,” he said.

“All the minerals drained down into the main passage, I guess,” Jenny said. “Some of these crystals are really pretty.” Her camera flashed again.

Sean squinted at a dark streak on the wall. “This doesn’t look like a mineral,” he said, sweeping his glove across it. “It’s more like—ouch!”

“What happened?”

“Stuck my finger. Went right through my glove,” Sean said, pointing to a sharp little crystal spike, dull gray and not more than a couple of centimeters long.

“You need medical aid?” Jenny sounded panicky.

“Just a pinprick. I’ll check the glove before we head back up, though, to make sure I don’t have a leak. This is small enough that it should seal itself without—hey, look at this.”

He held up his fingers, rubbing the tips of them together. Jenny shone her light on the glove. “What is that?”

“Feels like … but it can’t be.” On the fingers of
Sean’s glove was a dark orange-brown substance, a blobby smear that spread as he rubbed his fingers. It was almost like … “Mud?” he asked.

Sean turned his light onto the rock wall again. The dark streak led from the crack overhead down to the sandy floor. He prodded at the sand with the toe of his right boot, and it behaved strangely, clumping together like snow. “Jenny, look at this stuff. This is wet!” he said.

He heard Jenny gulp. “The air pressure is high enough. Liquid water! That hasn’t existed naturally on Mars for—Sean, do you realize how big this might be? Come on, we’ve got to tell them!”

If Miles’s discovery hadn’t caused an uproar, Sean’s more than made up for it. Everyone had to come and see, and even Rormer got involved, taking samples of the sand, scrapings from the trickle, storing everything in biotight containers. It didn’t amount to much, more dampness than wetness. Rormer couldn’t even get a single drop of clear water from the orange-brown slime, though he tried hard enough. Miles himself supervised, excitedly speculating that perhaps, a little farther underground, just perhaps, there might be
enough liquid water for some lingering Martian bacteria to have survived—

But Ellman cut through his excitement with a flat statement: “That will have to wait for a later expedition. Our orders are to finish up and start our return trip today. We’re going to do so. Hurry up with your samples, tell our photographers what they should record, and make sure everything is secured. We’ve got two hours, and then we’re starting back.”

Rormer, kneeling, said suddenly, “Look at this!” He had dug down into the wet sand and had uncovered a scattering of tiny little blue crystals. He scooped some up on a sampling trowel and held them under his helmet light. Sean, remembering his job, snapped a picture.

What Rormer held looked like BB pellets packed into the sand, though if anything, they were even smaller than that—tiny round spheres, their surfaces glowing a brilliant sapphire blue in the helmet light.

“Blueberries!” Miles said exultantly. “That’s what those are. They’ve only been found in brine basins on the surface before!”

Sean looked at Jenny and mouthed “Blueberries?”]

“Later,” she mouthed back.

“Mr. Doe,” Ellman said dryly, “I’m sure that Miss Laslo’s face is enchanting, but will you please pay attention to your photography? I believe Dr. Rormer is waiting for you to finish your pictures. Thank you.

With his face burning, Sean snapped away.

That evening, when they
were once again in a tent, Sean asked Jenny, “Blueberries? Is that what you called those things? What the heck are blueberries? I mean, they can’t be real berries, not on Mars. Are they some kind of rock, or—”

Jenny gave him a funny look. “Haven’t you read your history?”

“Enough to know that no berries ever grew on Mars,” Sean said grumpily. If Jenny had a fault, he thought, it was that she was so bookish, especially
when it came to subjects that interested her.

“No, of course the Martian blueberries aren’t
fruit
. That’s just a name someone tagged them with when—look, these things have been known for ages and ages. If I’m not misremembering, way back during the very first unmanned explorations of the planet, people found blueberries. I think it was one of the United States surface rover missions back in the twentieth century, or maybe the early twenty-first. They called them ‘marbles’ then.”

“Marsbles, you mean,” Sean said, laughing. “Too small for marbles. So what are they?”

“Concretions of minerals,” Jenny said. “They’re kind of mysterious, even today. Nobody knows exactly how they formed. At first people thought they might be ejecta, material that was blown out in volcanic eruptions or thrown up into the air by meteorite impacts, but that doesn’t seem to be the case. You only find them in Martian sedimentary rock, in basins where there was standing salty water eons ago. They’re not perfect spheres, but they’re so round they have the look of something made artificially.”

“But there were never any Martians.”

“Well, so far as we know,” Jenny conceded. “Though we’re sure there were some very basic Martian life-forms. Did you know that on Earth they’ve found meteorites that were blasted off the surface of Mars and that show evidence of bacterial life? It’s even possible that some Martian bacteria might have reached the Earth alive.”

“But bacteria don’t
make
things. They couldn’t have made the blueberries.”

“I didn’t say they did,” Jenny protested. “I just meant that the blueberries look artificial, as if something made them, that’s all.”

“Just because they’re round? River rocks are round,” Sean said. “No one thinks they were chiseled out by river gnomes or anything.”

“Rivers on Mars didn’t last long enough to leave any river rocks,” Jenny shot back. “And yes, it’s possible that some kind of natural forces shaped the blueberries. But really, the odd thing is that even after people actually got their hands on the samples of these things, no one could figure out exactly what
they were. They contain pretty high levels of copper, which is odd because copper is fairly rare on the surface of Mars. And they’re always found in areas where there are trace fossils that just might be the remains of Martian bacteria, so it’s just barely possible that the two might go together somehow.”

“Well, the two of us found the first underground blueberries on Mars,” Sean said, yawning. “So maybe we’ll go down in the history books.” He reached for a water bottle and a ration pack without much enthusiasm.

“How’s your finger?” Jenny asked. “How badly did you cut it?”

Sean held up his forefinger, putting on a pained expression. “Stabbed to my very heart, I am. Scarred for life. My life’s blood flowing out like a mighty river. My tender young flesh forever mutilated—”

Jenny was shining a flashlight on his fingertip and closely inspecting his skin. She snapped off the light. “Oh, shut up. I don’t see anything.”

“There’s nothing to see,” Sean said. He rubbed his finger with his thumb, searching. It was hard even for
him to tell exactly where the little prickle was located on his fingertip. “It’s right here,” he said finally. “Right where my thumbnail’s touching. See anything?”

Jenny turned the flashlight on and practically touched his finger with her nose, frowning intently. “No,” she said after a moment. “How about your glove?”