That changed in the spring of her first year of medical school. There was a talk on the campus sponsored by the Mars Society, and she had almost not gone at all. It was certainly far removed from studying medicine. In the end that was why she had gone, because she needed to take a break; she wanted to get away from the medical school and the arrogant pricks who were her fellow students, and the lecture was cheaper than a movie.
They had brought in an astronaut to speak. He was a Canadian, younger than Tana had expected, a boy with long dark hair tied in a ponytail.
Much later, when she spent two years training with him, she would never mention that she had first seen Ryan Martin at a lecture at Case Western Reserve. She doubted that he realized she had met him before; the auditorium was packed, and she was in back, and who was she then, anyway? Just another anonymous face in the crowd. And she would certainly never admit that, once long ago, she’d had an intense puppy crush on him.
But he had spoken with such evangelistic fervor. Mars, he told them, was not an impossible target. With clever planning, it could be done. Should be done. He showed slides and talked about evolution, and about human destiny, and about how, someday, humans would not only have colonies on Mars, but they would terraform the planet. Mars is cold and dry and lifeless, but with coaxing, with engineering, it could be warmed, could be made into an inviting, living planet. And a trip to Mars need not be expensive. It all depends, he told them, on the ability to make rocket fuel on Mars, and he laid out all the elements of the Mars expedition, almost exactly the way that, fifteen years later, it would actually happen. “And you can go,” he said. He pointed into the crowd. “You.” He pointed a different direction. “You, too.” And then he pointed at the back of the crowd, directly at Tana. “And you.”
And Tana had been hooked. In college she’d set aside her science fiction as foolish fantasies of childhood. She’d never considered becoming an astronaut before, hadn’t even considered the possibility, but now she was ready to go to Mars.
Her infatuation with Ryan Martin didn’t last; he left the campus the next day, and she never even spoke with him. Later, when she married Derrick, she had already long forgotten that she’d ever even briefly had a crush on a lecturer. But the dream of going to Mars had been ignited, and it was a flame that would never, quite, go out.
10
Cave
Tana was the next down, and in fifteen minutes she was standing on the smooth floor of the cave and added the beam of her light to Ryan’s. The crystals were indeed salt, she realized. Even the purple ones; eons of exposure to cosmic rays had slowly infused color into the crystals nearest the edge of the canyon.
Except for the salt crystals, the cave was almost entirely featureless, with a smooth flat ceiling, and an equally even floor, devoid of stalactites or stalagmites or any other cavelike geology.
The explanation, Tana realized, was that there must once have been immense salt flats here, remnants of some ancient ocean bed that had long since dried up, leaving only the salt behind. And then, over the ages, the salt flats had been buried under ash and lava from the eruptions of the great Tharsis volcanoes. Then, when the Valles Marineris had been carved like a knife-cut into the crust of the planet, exposure to water had dissolved away the salt layer, leaving a wide, horizontal cave in the side of the canyon, ten feet high and hundreds of miles, perhaps thousands of miles long.
How extensive was the salt layer, Tana wondered? Had the entire planet been covered with an ancient ocean? Did the entire planet have a buried layer of salt, hidden under the crust? Or was it just this area near the equator? And, more important, had the ancient ocean ever developed life?
She wanted to stay, to explore the caves, to investigate the rocks with a microscope to search for possible microfossils, but it was impossible. They had to move on or die.
But it wouldn’t hurt for her to look just a little bit. In fact, it made sense for the others to rappel down before she moved on.
The crystals—Ryan hadn’t mentioned how big they were. Here was a cluster of crystals, each one the size of a milk carton, with edges so rigorously square that they looked as though they had been machined; another one was a perfect octahedron, like some modern sculpture of glass. Were they all salt? The top layer certainly was, but it looked like there was something else underneath, something a whiter color, almost a milky blue. She scraped off the top layer. Yes, it was something softer, definitely different, not just rock salt. There was a mass spec back at the rockhopper; if she took some samples, they could analyze them later.
Was it the same all the way back?
Tana shone her beam into the back of the cave and walked farther to see just how far back it went.
11
Interview
It was a big conference room, with a faux-mahogany table and upholstered seats that swiveled and tilted. With only two of them in the conference room, it seemed empty. Tana fought the impulse to lean back in the comfortable chair while waiting for the interviewer to speak. She knew she had the credentials; what was important now was not to blow her chances by saying something stupid or giving the wrong impression. She sat up rigidly straight to make it clear she was interested.
At last the interviewer looked up at her. She didn’t know him personally. He was one of many anonymous, well-groomed men in impeccably tailored suits. One of a network of interconnecting country-club acquaintances that—regardless of what the organization charts may imply—held the real power in the center. He said, “Do you think you deserve a spot on the expedition because you’re black?”
“No, sir,” Tana said. “A Mars expedition is no place for deadwood. I deserve a position because I’m the best qualified for the spot.”
He looked back down and flipped through her papers again. She could see her application form stapled to the top, then transcripts, then employment files. “Hmmm,” he said, without looking at her. “Says here you did your residency in an emergency room…Still up to date on your skills?”
“Yes, sir. I volunteer at the free clinic every other week.”
“Well, that counts for something. We’ll need quick response if we have an emergency. But you’re not the only one with ER experience, you know. How’s your exobiology?”
“I’m working with Feroz and Papadopoulos,” she said. “It’s in there.”
She suddenly had to pee. She couldn’t possibly need to; she knew better than that. Before she went to an interview, especially one as important as this, she always hit the ladies’ room. But it sure felt as if she suddenly had a desperate need.
“Yes, Feroz and Papadopoulos…good credentials.” He looked up at her. “How’s the work going?”
They were cataloging stereoisomers found in Antarctic meteorites and in meteoritic dust samples gathered from high-altitude airplanes. The point was to establish whether a chiral asymmetry existed in samples from the primordial nebular material, and, if so, whether it had been modified in the subsequent five billion years of solar system evolution. If they found conclusive evidence that chiral asymmetry predated life on Earth, it would be a landmark achievement in exobiology, since so far the chiral nature of organic compounds on Earth was a sure signature of life. But so far, like the signs of life in Martian meteorites, their evidence remained tantalizingly suggestive, but inconclusive.
She resisted the urge to shrug. “It’s going well,” she said.
“You like the lab work?”