Return to Mars

by Ben Bova

  Jamie glanced at Stacy Dezhurova, sitting beside him in the pilot’s Heat. The rover was almost to the bottom of the landslide now. Morning sunlight had reached the floor of the Canyon, driving the mist away.

  “I’ve heard about your cliff dwellings,” Trudy Hall said from behind Jamie, very softly, as if it was a dangerous topic.

  “It’s only one,” Jamie corrected, “and it’s not my cliff dwelling.”

  “But you’re the only one who believes it is an artifact,” Trumball pointed out.

  “It’s not on the mission schedule,” Hall said, still in a hushed, almost scared voice.

  “There’s plenty of flexibility built into the schedule,” Jamie pointed out.

  “Enough for us to salvage the old rover and go after the Pathfinder,” said Trumball brightly.

  “Maybe.”

  “Why not? We could tow the old clunker out of the sand on our way back from here,”

  Jamie nodded slowly, his mind racing. I’m the mission director, he told himself. I can set an excursion to the cliff site when I see fit. I don’t need his permission or even his cooperation. I don’t have to let him go off on this crazy jaunt after the Pathfinder. I don’t have to offer him a bribe to do what I want to do.

  Yet he heard himself say, “We’ll stop and inspect the old rover on our way back to base, Dex.”

  “Great!”

  “That doesn’t mean that we’ll do anything more,” Jamie warned. “I agree with you to this extent: we ought to see if the old rover is still usable.”

  “It will be.”

  “Because you want it to be?”

  “Because it will be,” said Dex, as convinced of the notion as a little boy who still believes in Santa Claus.

  For three days Trudy Hull studied the lichen living just beneath the surface of the rocks at the base of the Canyon cliffs. Three days and three nights.

  Hall’s purpose was to study the organisms in their natural habitat, especially their diurnal cycles. To do so, she had to leave the lichen undisturbed, so her instruments were mainly remote sensors. She took photographs, set up thermometers that recorded the exterior and interior temperatures of the rocks continuously, sampled the Martian air micrometers from the lichen and monitored with infrared cameras the heat flow from rocks that bore lichen and others that did not.

  On the second day she began making more direct measurements of some of the lichen: with Jamie’s help she inserted probes into several of the rocks to measure chemical balances.

  Trumball, meanwhile, collected rock samples, dug shallow cores (finding no permafrost at all), and began the detailed geological mapping of the area. And, of course, he planted a half-dozen geology/ meteorology beacons along a carefully paced path that paralleled the cliff face. Jamie helped him. Dex made a few cracks about the mission director serving as his assistant. Jamie let them slide past without comment.

  “We need to get samples from the cliff itself,” he told Jamie the second evening of their stay in the Canyon. “And implant beacons in the cliffs.”

  Jamie nodded agreement. The two of them were just inside the airlock hatch, vacuuming off the dust from their hard suits with handheld cordless Dustbusters. The Martian dust smelled pungent with ozone, enough to make eyes water if it wasn’t cleaned off immediately.

  “Still no permafrost?” Jamie asked, over the whine of the vacuums.

  “Not a bit. Must be deeper below the surface. It’s a couple of degrees warmer down here, y’know.”

  “But the heat flow measurements—”

  “Yeah, I know,” Trumball interrupted, bending over to clean his boots. “Less heat flow from the interior here than up topside.”

  “But no permafrost.”

  “It’s got to be deeper down.”

  Jamie shook his head. “Doesn’t make sense. How can the lichen live here if there’s not as much heat coming up from the interior and water is farther away?”

  Trudy Hall, sitting on her bunk with her laptop computer on her outstretched legs, called to them, “Listen to my seminar after dinner and all your questions will be answered.” Then she made a thoughtful face and added, “Well, some of them, at least.”

  Hall’s impromptu seminar started after the remains of their dinners had been slid into the recycling bin and the folding table mopped clean of crumbs. Jamie drew his second cup of hot coffee, then sat on his bunk. Dex sat next to him, nursing a mug of fruit juice. The upper bunks were still folded back against the curving shell. Stacy Dezhurova was up in the cockpit, checking the rover’s diagnostic systems, a chore she did every evening.

  Sitting her laptop on the table and using its screen to display photos and graphs, Hall showed the two men that the lichen draw their heat energy from the sunlight that warms the rocks during the day—“as high as twelve degrees Celsius in direct sunlight,” she reported.

  “So they don’t depend on heat flow from the interior,” said Jamie.

  “Not at all.”

  “That’s why—”

  “More than that,” she went on. “They actually maintain a higher temperature than ambient!”

  “What?”

  Her eyes alight with excitement, Hall told the two men, “The rocks that hold lichen in them are six to twelve degrees warmer than rocks without lichen.”

  “How do they do that?” Trumball asked.

  “The lichen store heat, as if they’re warm-blooded!”

  “But they’re plants, not animals,” Jamie protested.

  Hall waved a hand in the air. “I don’t mean that they’re actually warm-blooded, of course. But somehow they maintain a higher temperature than the unoccupied rocks. They actually store heat! It’s unprecedented!”

  “Are you sure?”

  “How much cold can they take?” Trumball asked.

  Hall shrugged her slim shoulders. “They’ve survived for goodness knows how long. Overnight lows get far below minus one hundred.”

  “What about dust storms?” Jamie wondered.

  “What about them?” she countered.

  “Well, the rocks can be covered with dust for days at a time, maybe more. …”

  “Ah, I see,” Hall said, bobbing her head up and down briefly. “The lichen must be able to survive such blanketing.” Her brow knit with thought. “I don’t know how a layer of dust would affect the temperature of the rock. Is the dust a thermal insulator or would solar infrared get through it without much absorption?”

  Jamie and Trumball both shook their heads. Hall tapped out a note on her laptop keyboard. “That’s something we’ll have to look into, isn’t it?”

  “If the lichen get their water from the humidity in the atmosphere,” Trumball pointed out, “several days of being covered with dust would desiccate them, wouldn’t it?”

  “Obviously not,” Hull said. “Otherwise they would have died out long ago, don’t you sec?”

  Jamie said, “Then they can go for some time with no water input at all.”

  “Apparently. Unless they can obtain water from another source.”

  “Such as?”

  She ran a hand through her mousey brown hair. “I haven’t the faintest notion. Dex, you say you haven’t found permafrost below the surface, is that correct?”

  “Not yet,” Trumball replied. “It may lie deeper than my probe can reach.”

  “Have you tested the humidity of the soil?”

  Slouched back against the rover’s curving shell as he sat on the bunk beside Jamie, Trumball said, “It’s part of the automatic analysis program. Not enough H2O to register, so far.”

  “The lichen must be able to hibernate, sort of,” Jamie suggested. “Slow down their metabolic processes when they can’t get water and wait it out.”

  “That’s what they do on Earth,” Hall agreed.

  Trumball’s eyes lit up. “Y’know, there’s probably hydrates in the rocks. Maybe the lichen can separate them out, chemically, and use their water!”

  “Has anyone—”

 
Jamie cut Hall’s question short. “There are hydrates in the rocks,” he said, more to Trumball than Trudy. “We found that out on the way back during the first expedition. Not the rocks up on Lunae Planum, but the rocks we picked up down here in the Canyon definitely bore hydrates.”

  “Water molecules locked up in the rock’s silicates,” Trumball said. “Yeah.”

  Across the table from them, Trudy Hall sat up straighter. “We’ve got to see if the lichen can extract water from the hydrates!” she said, her voice trembling slightly with eagerness.

  She and Trumball launched into an animated dialogue on how to test the lichen. Jamie watched the excitement on their faces, the fervor in their voices.

  “We’ll have to take samples and bring them back to the base,” Hall said. “I don’t have the facilities to do the work here.”

  “Take whole rocks and keep ‘em in sample boxes outside the rover,” Trumball recommended. “Don’t take any chances on contaminating ‘em.”

  “Right. But where can we store them?”

  Trumball got up from the bunk and went around the table to sit beside her. They bent over her laptop screen, heads practically touching.

  Stacy Dezhurova came hack from the cockpit and cast an eye at the two of them, chattering and tapping away at the laptop keyboard.

  “What is going on?” she asked Jamie.

  “They’re trying to figure out where they can hang a few sample boxes outside the rover for the trip back.”

  “Outside? Take your pick. We have attachment points every few meters on the outside skin.”

  With that problem solved, Dezhurova slid past Jamie and headed for the lavatory. Jamie sat alone on his bunk, feeling left out. They’re no excited about this that they’re oblivious to everything else, he told himself.

  Then Hall looked up from the screen and said, “But don’t you understand what this means? About the lichen’s heat capacity, I mean.”

  Trumball looked puzzled for a moment.

  Jamie started to think: If the rocks with lichen in them are warmer than rocks without lichen, then—

  “We can map them from the satellites!” Trumball snapped.

  “Right-o,” exclaimed Trudy. “The infrared sensors in the satellites can detect temperature anomalies on the ground …”

  “And the warmer patches will be where the lichen are living,” Jamie finished for her.

  “Hey, we could get a complete map of the whole planet in a few hours that way,” Trumball said. “Tell us exactly where colonies of lichen are living!”

  “It’ll take more than a few hours,” Jamie cautioned. “We’ll need to make several passes, make certain the data’s firm, cover the same territory several times to nail down the temperature differences.”

  “Can the satellite sensors measure a difference of six degrees or so?” Hall asked.

  “Sure,” said Trumball. “Easy.”

  “Ground temperatures, I mean,” she said.

  Jamie said, “I’m pretty sure that won’t be a problem, Trudy. There isn’t much absorption from the atmosphere; it’s so thin that ground heat escapes right into space. That’s why it gets so cold every night, no matter what the daytime temperature is.”

  She nodded thoughtfully. ”Five or six degrees, then. If the satellites can measure that small a difference we can map the whole planet and see where the lichen colonies are.”

  “Or other forms of life,” Trumball suggested.

  “We haven’t found any other forms, as yet,” she said.

  “We will,” Trumball answered confidently.

  “I hope so.”

  “Let’s pull up the specs on the satellites’ sensors,” Trumball said. ‘ “That oughtta tell us whether the IR scanners can measure your temperature differences.”

  Hull nodded eagerly, and Trumball pulled the laptop toward him and began lapping on its keyboard. Jamie got up and made his way up to the cockpit. Time to check in with the base and make the nightly report, he thought.

  NIGHT: SOL 10

  VIJAY SHEKTAR WAS ON DUTY AT THE COMM CONSOLE. SHE SMILED AT Jamie. “How’s it going, mate?”

  “Really well,” Jamie said. He related their hypothesis about the lichen leaching water from their host rocks’ interiors and the possibility of scanning the whole planet for colonies of lichen.

  “That’s wonderful, Jamie,” Shektar said, smiling happily.

  “Trudy’s a really sharp one,” he said. “She’s on her way to a Nobel.”

  “Good for her,” Vijay said, a bit abstractly, Jamie thought.

  Then her smile faded and she asked in a lower voice, “How are you and Dex working out?”

  Jamie thought of two nights ago, when he wanted to talk to her, but she was locked in chat with Trumball.

  Keeping his face impassive, Jamie replied, “Not bad. He wants to salvage the old rover.”

  “Yes, I saw that in your report from last night.”

  “And he’s offered me a bribe to do it.”

  “A bribe?”

  Jamie explained about the cliff dwelling.

  Shektar said, “But you were going to do that anyway, weren’t you?”

  He had to admit it. “I certainly intended to. But now that Dex has brought it out in the open, I’m kind of glad about it.”

  “That’s good.”

  “Uh … you were talking with him a couple of nights ago, weren’t you?”

  Her dark-skinned face showed no trace of surprise. Her onyx eyes did not waver. “Jamie, I try to talk to each team member every few days. It’s part of my job.”

  “I understand,” he said.

  With a smile, she said, “Sure you do.”

  Suddenly Jamie felt uncomfortable. He wanted to talk with Vijay for hours, talk about everything and anything, not just the business of the expedition. Yet he sensed that she knew more about what was stirring inside him than he himself did.

  “Are you okay?” he heard himself ask. “Everything going well buck there?”

  “We’re all fine,” Vijay said. “Possum’s drill has reached the two-hundred-meter level and he’s starting to pull up bacterial samples. He und Mitsuo are burning up the lab equipment, examining them.”

  “Living bacteria?”

  “Yes. The biologists back on Earth are dancing in the streets, to hear the two of them talk.”

  “Why the hell didn’t they tell me about it?”

  She looked startled. “I thought they did. They just pulled up the first sample this morning. I thought they sent you a quick report.”

  Jamie took a deep breath. “Maybe it’s in my incoming mail. I haven’t checked it this evening.”

  “I’m sure it must be.”

  Without breaking his connection with Shektar, he pulled up the list of incoming messages. Yes, there were two of them from Fuchida, sent within minutes of each other, less than three hours earlier.

  I ought to check my mail before I call the base, Jamie reminded himself. He realized he had been foolish, wanting to talk to Vijay so much that he neglected to go through his incoming messages first.

  She was saying, “Mitsuo thinks the volcanoes might be even better sites for an underground ecology. He can’t wait to get started on his excursion.”

  Jamie sighed. “I know the feeling.”

  “You’re well?” she asked.

  Almost startled by her simple question, Jamie answered, “Sure, I’m fine.”

  “Not feeling tired or perhaps a little irritable, especially in the evening?”

  Jamie shook his head. “No, nothing like that.”

  “How about when you wake up in the morning? Any signs of depression?”

  “What are you talking about?” He remembered how he had felt during the first expedition when vitamin deficiency had brought on scurvy. Is Vijay worried about that? he wondered.

  But she answered, “Jet lag.”

  “Jet lag?”

  Shektar nodded, quite serious. “The Martian sol is more than half an hour longer tha
n an Earth day. Several of the people here at the base have shown some difficulty in adjusting their internal clocks.”

  Jamie was instantly alarmed. “Who? How serious is it?”

  “It’s not serious,” Shektar replied. “Nothing to he worried about. And I’m not going to break doctor patient confidentiality over it.”

  “But if it affects people’s performance—”

  “It hasn’t and I doubt that it will. They’re adjusting; just a bit slowly, that’s all.”

  Jamie tried to keep himself from frowning at her. We should have thought of that, he scolded himself. We made the adjustment for the gravity, but nobody thought of adjusting for the different length of day.

  “Cheer up, Jamie,” Vijay said, smiling again. “It’s nothing for you to worry about.”

  “You’re sure?”

  “Yes, I’m absolutely, positively certain.” Then her smile turned impish. “Pretty much.”

  They bantered back and forth about internal biorhythms and natural cycles. Jamie enjoyed chatting with her; he could feel the tensions of the day relaxing their hold on him. He noticed how white her teeth gleamed against her dark complexion. Her skin looked smooth and soft. Jamie thought how he’d like to stroke her face, her shoulders …

  “Talking about biorhythms,” Vijay was saying, “I’ve been keeping an eye on the harem effect.”

  That put an end to his fantasizing. “On what?”

  “The harem effect,” she said. “The tendency of women who live together to have their menstrual cycles synchronize.”

  Jamie said to himself, I don’t want to hear about this. But he heard himself ask, “Is that happening here?”

  Shektar nodded, her eyes teasing. “Indeed it is, mate. I talked with Stacy a little while ago. We’re all within three days of each other.”

  “The harem effect,” he muttered.

  “Part of the general cussedness of nature,” she said.

  “Is it?”

  “We don’t do it on purpose, Jamie. We can’t control our cycles, not unless we take hormone therapy, and as far as I know none of us is on birth control pills.”

  Jamie thought maybe they should be, then wondered why they weren’t. Because they don’t want to be sexually active?