"Different gravity field," Naguib said, as if that explained everything.
"Yes. Of course."
After a full day’s travel, a night’s stop out in the open plain, and a morning of jouncing over the roughening terrain, the rover was still more than a hundred kilometers from the base of Pavonis Mons. It was too big to be seen in its entirety close up. Only from this distance could they view the entire structure.
Like the volcanoes that formed the Hawaiian Islands, the giants of the Tharsis region are shield volcanoes, lofty cones surrounded by wide bases of solidified lava. Pavonis Mons was the central of three such volcanoes, and the closest to the explorers’ domed base. The two others sat far over the curving horizon. Farther still beyond them was the most massive — and tallest — volcano in the entire solar system: Olympus Mons.
Pavonis Mons is a middleweight in comparison to mighty Mount Olympus. Pavonis’s base is scarcely four hundred kilometers across, about the width of Ohio. Its peak is hardly ten miles above the uplifted plain on which the rover sat. At its top is a crater, a caldera, barely wide enough to swallow Delhi or Calcutta.
For all its size, though, its slope looked deceptively gentle. Not like the steep rugged peaks of the Himalayas; Pavonis Mons’s flanks rose at a five-degree angle. Patel thought a man might walk to the summit easily, given a few days, and peer down into that yawning caldera. Was it truly dead? Or would he see fumaroles venting steam or wisps of other gases, preparing for the next eruption? The sky looked clear, cloudless. But what would he find if he could get to the top?
Patel shook his head, almost in tears, and said to Naguib, "To think that we will have only three days to spend there. Three little days! It would take months merely to make a preliminary survey."
This excursion to Pavonis Mons had been the first casualty of Jamie’s insistence on returning to the Grand Canyon. The original mission schedule had called for a week’s stay at Pavonis. That had been cut to three days.
Naguib gave him a fatherly pat on the back. "Even three years would not be enough. A man could spend his entire life studying this beast."
"It isn’t fair!" Patel burst out, banging a fist on the back of the empty pilot’s seat. "The entire reason for my coming to Mars was to study the Tharsis shields and now this… this… upstart…"
"Calm yourself, my friend," said Naguib. "Calm yourself. Accept what cannot be changed."
Patel pulled away and walked down the rover module as far as the airlock hatch. Then he turned back toward the Egyptian. The two men stood silently, facing each other along the narrow length of the module: the slim, liquid-eyed Hindu, his dark face shining as if sheened in sweat; the older, stockier geophysicist, graying at the temples, lines etched at the corners of his eyes and mouth.
"The next thing you will tell me is that this is the will of Allah," said Patel.
"I am an atheist," Naguib replied, smiling gently. "But I realize that our Navaho friend has prevailed with the mission directors, and the Americans have seized control of the mission plan. There is nothing we can do about it."
They heard the clumping of the two other men entering the airlock. Patel’s slim hands clenched into fists, and for a moment Naguib thought that he would gladly murder Waterman.
While the three geological scientists were off on their excursion, the three biological scientists spent their spare time planning the coming trip to Tithonium Chasma.
They sat at the galley table, strewn with maps and photographs taken from the orbiting spacecraft. They had all watched Jamie’s videotapes until they knew them by heart.
"Is it possible to believe that the formation could be a building of some kind?" Monique Bonnet asked.
Tony Reed, who had joined the three women when he saw them bringing their photos and papers to the galley, dismissed the idea. "It’s projection on Jamie’s part, a well-known psychological phenomenon," he said. "We see what we want to see. We hear what we want to hear. That’s how palm readers make their money, telling their customers what they want to hear, no matter how outrageous it is. Something in Jamie’s subconscious wanted to see cliff dwellings and, voila! he saw them."
Ilona leaned back in her chair, reminding Reed of a tawny jaguar stretching on a tree branch.
"The formation truly exists. It is not imaginary. We will see for ourselves whether it is natural or artificial once we get there," she said, her husky voice sounding almost bored with the subject. "For now, we must decide which of us goes on the excursion with Jamie."
Joanna nodded agreement and turned to Monique.
"You go," said the French geochemist. "The two of you. I will remain here and tend the plants."
Ilona frowned at her.
"You don’t want to go?" Joanna asked.
Monique made a Gallic shrug. "You want to much more than I do. It makes more sense for our biologist and biochemist to go."
"But you are a part of our biology team, too," said Ilona, straightening up in her chair. "We will need your expertise to test the soil at the bottom of the canyon."
"You can bring samples back here to me."
"But what about fossils?" Joanna asked, looking worried. "You have the most training in paleontology. We might miss something."
Monique laughed lightly. "If there are any bones or skulls out there I’m sure you can find them as easily as I."
"Microfossils?" Reed asked.
She turned her dimpled smiling face to the Englishman. "Tony, I have scanned every soil sample that we have taken. I have cracked rocks open and put microtome-thin slices under the microscope. There are no fossils. No microbes, living or long dead."
Reed fingered his slim moustache. "Well…"
"But, Monique," said Joanna, "suppose we come across fossils at the bottom of the canyon but we don’t recognize them as such? Organisms native to Mars. How would we know that we are looking at fossils?"
"How would I know?" Monique shot back. "How would any of us?"
Joanna cast an uneasy glance at her colleagues around the table.
Reed broke into a wide grin. "A classic problem, isn’t it? How do you recognize something that you’ve never seen before?"
The three women had no answer.
Jamie could feel the hostility building within the cramped confines of the rover with every kilometer they covered on their way to Pavonis Mons.
Dinner that evening was virtually silent. Even Mironov, whose normal expression was a pleasant smile, had nothing to say, no jokes to offer. Patel, perched like a nervous bird on the edge of the bench across the narrow table from Jamie, would not look at him.
Naguib tried to ease the tension.
"Tomorrow we reach the fracture zone, at last," he said, mopping up the last bits of his meal with a thin piece of pita bread.
Feeling grateful, Jamie answered the older man, "Right. And we begin to get some absolute dates for the age of the lava flows."
Patel put his fork down. "We have three little days to do the work that was originally scheduled for a full week."
"I’m willing to work double shifts for those three days, Rava," said Jamie. "I know you…"
"You know nothing!" the Hindu snapped. "Nothing except your mad desire to go to the canyon again and make yourself the hero of this expedition."
"Hero?"
"Do you know how many years I have spent studying the Tharsis volcanoes? Not three. Not five. Not ten." Patel was trembling with rage. "Fifteen years! Since I was an undergraduate in Delhi! For fifteen years I have pored over photographs of those shields, studied the remote measurements made by spacecraft. And now that I am finally here, you have cut down my time to three miserable days."