The Quest for Mars: NASA scientists and Their Search for Life Beyond Earth
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The message in a bottle had arrived, but who would decipher it correctly?
Throughout the summer of 1996, David McKay expected a backlash concerning his discovery, but it was slow in coming. At first, members of the public, some of them deeply suspicious of all federal agencies, NASA included, sent him angry e-mails, most of which echoed the theme, “What kind of fools do you take us for?” One said, “Your life on Mars story is a good example of your mistaken belief that the general public is comprised of a bunch of total idiots.”
Eventually, scientists joined the clamor. Some insisted that ALH 84001 proved absolutely nothing. The wormlike structures, said critics, were far too small to be bacteria; in fact, they were many times smaller than the smallest bacteria ever seen on Earth. Others insisted that if the meteorite contained evidence of biological activity, it was the result of contamination. Still others challenged the team’s analysis of the PAHs. Some scientists stated flatly that McKay and his team had unfairly manipulated the evidence to support a flawed hypothesis. Everett Shock at Washington University invoked the Murchison meteorite, believed to have come from the asteroid belt, to invalidate the discovery. “It has carbonate minerals in it,” he said, “and real solid evidence of water – yet there isn’t anybody saying that there is life in the asteroid belt.” True, no one was saying it at the time, but that situation is beginning to change as scientists have come to think of life as widely distributed throughout the Solar System. Finally, the scientists attacked the reputations of McKay and his team, a tactic that took cooler heads by surprise. “It’s kind of strange when scientists, who are thought to be rational, become emotional,” said Marilyn Lindstrom, a curator of meteorites at the Johnson Space Center. “What bothers me most is that so many people have made up their minds before the data come in. I mean, sometimes I’m amazed by McKay and Gibson’s almost true-believer attitude.”
Carl Sagan was seriously ill at the time of the announcement, with only a few months to live. During his decades with NASA, he had become familiar with both the science and the passions involved in the search for life beyond Earth, and his pronouncement on the subject was enlightening yet equivocal. “For years I’ve been stressing with regard to UFOs that extraordinary claims require extraordinary evidence. The evidence for life on Mars is not yet extraordinary enough. But it’s a start.” Although he was deeply intrigued by the meteorite team’s findings, Sagan insisted that more study was required. Yet other scientists were convinced by McKay’s rigorous approach. “If this is not biology,” said Joseph Kirschvink of Caltech, “I am at a loss to explain what the hell is going on. I don’t know of anything else that can make crystals like that.”
Because McKay, Gibson, and company were cautious, even cunning, in the way they stated their findings, they made it difficult for their critics to disprove their argument. The meteorite team held that the fossils were merely possible evidence of relic life; they were not the only explanation for what they’d found, merely the best explanation. To disprove or dismiss these findings, their critics would have to understand ALH 84001 even better than the original investigators did. They would have to refute four separate, interrelated lines of argument. They would have to be familiar with geochemistry and physics and geology and of course biology. No one person knew enough about all these fields as they applied to the meteorite; it would take a team, a bigger and better team, to show McKay and his colleagues the error of their ways.
The significance of the debate transcended the meteorite itself. Even if it contained crystals that mimicked biological morphology, or contamination, the search for extraterrestrial life had undergone a sea change. Even scientists who thought ALH 84001 contained no life signs at all now found themselves thinking that if we were going to find evidence of extraterrestrial life, it would probably be tiny and ancient and carried throughout the Solar System in a meteorite. McKay, Gibson, and Thomas-Keprta’s real discovery was a new paradigm. Even if their conclusions turned out to be incorrect, their thinking was too sophisticated to dismiss. From now on, they would define the terms in the search for extraterrestrial life. Their credibility rested not so much on what they found as on how they found it: their precise, rigorous methodology.
Two years after the announcement, I found Kathie Thomas-Keprta in the featureless Building 31 at the Johnson Space Center, where many of the crucial discoveries concerning the meteorite had occurred. She is tall and slender, with long blond hair swept up in back. Despite the intense debate concerning her work, she didn’t look embattled; she was poised, with a certain swagger and the smooth delivery of a television talk show host, at least in one-on-one conversation. We were standing beside another Martian meteorite, EETA 79001, a cousin of the more famous ALH 84001. EETA 79001 resembles a black ice cube, about two inches by two inches. I peered carefully at this Martian specimen. There wasn’t much to see except for a little hole in one side drilled by a laser to extract gases trapped within.
Her team expected a lot of debate after their discovery, she told me, although the vehemence came as a surprise. “Still, all the criticism and attacks on our findings don’t bother me because I’m from Green Bay Wisconsin, and I’ve been a Packers fan for thirty years, and I know what it’s like to hang in there from one losing season to the next.” She thought it would take five to ten years for their findings to be fully vindicated, and she couldn’t wait for that day. Her case now was stronger than ever, she said. The recent discovery of microorganisms far below the Columbia River, in Washington State, gave her a lot of corroborating evidence for nano-life on Mars. No one expected to find nanobacteria a mile or more below the surface of the Earth, and no one knows how they started growing. Like their ancient Martian cousins, they live in basalt. More important, they are almost as small as the Martian nanofossils. Critics of the meteorite team insisted that the presumed nanofossils in ALH 84001 were much smaller than any organisms found on Earth – too small to be considered micro-organisms. Since the Columbia River discovery, that objection lost much of its force.
I wondered what kind of energy source for life could be found in rock a mile or two underground, where there is no sunlight, no lightning, no real heat from the Earth’s core. Some scientists think the source could be as simple as water passing over the basalt, which might cause a chemical reaction. If this is the case, the answer to the Genesis Question becomes simpler all the time; it appears that the rock bottom (so it might be said) requirements for life are even more minimal than scientists believed only a few years earlier. All you need is water and an energy source for life to emerge. Water might be running through subsurface basalt everywhere; the same thing might have happened on other planets, or even on asteroids; it might be happening now. There might be more ways for life to emerge than we now imagine – enough to suggest that life really is an inevitable outcome of chemistry and an inevitable part of the universe, predestined, as it were, but so simple that we hardly acknowledge the phenomenon for what it is.
David McKay is tall, slender, silver-haired, professorial, imposing. As the leader of the meteorite team, he is suspicious of outsiders and chooses his words with care. His office, where we met, is capacious, even by the standards of the sprawling Johnson Space Center, and the walls are lined to the ceiling with plaques, awards, degrees, citations, and a child’s squiggly drawing of a small Martian meteorite beside a large man labeled, “Dad.”
“We are still getting new data,” he said, as he snacked on a small bag of pretzels, eying me warily. He wasn’t exactly thrilled that I’d appeared in his lair; he was sensitive to criticism and assumed I was about to add my voice to the chorus of those who angrily criticized his findings. He was about to dismiss me – or so it seemed – but he thought again, and decided to test his case with me. “We are very excited about the data from the meteorite called Nakhla that fell in Egypt in 1971,” he said. “The British Museum had a piece the size of a potato, covered with fusion crust, which protects it from contamination. The problem with the Allan Hills meteorite, ALH 84001, is that it may have been contaminated with carbon or terrestrial bacteria. A chunk of the Nakhla meteorite came in here, to our lab, and we had permission to break it up and pass it out to various investigators. We requested six grams. We think it’s likely to have the least contamination of any Martian meteorite.” I sensed he knew more, but this partial revelation was all he would risk revealing at the time.
He also wanted me to know he hadn’t given up on ALH 84001 as the prime suspect in the search for life on Mars. He didn’t want me to think for one second that Nakhla was a substitute for ALH 84001; rather, it offered supporting evidence. As he talked, it became apparent that he felt that all the criticisms leveled at his findings, and there had been a lot of them, more than most scientists encounter in a lifetime, had only strengthened the arguments he originally advanced. To illustrate what he meant, he invited me to sit with him before a large monitor. “Here’s a new picture from the Allan Hills meteorite. We really suspect these are fossilized bacteria. They have better characteristics than what we have already seen; they are curved, segmented. If you gave this to a biologist, he’d say, ‘Of course it’s bacteria,’ but we have to prove beyond a shadow of a doubt it’s of Martian origin and fossilized. Fossilization is very common with bacteria; the organic components are replaced by mineral components such as iron oxide or silica. This can happen quickly, in a couple of weeks, and it happens when you bury the material in water. They are one hundred to two hundred nanometers long and forty to fifty nanometers wide, smaller than the big worms in the published pictures, which were five hundred nanometers long. My guess is that life is still on Mars, but it’s underground, in the water system. That’s where the underground organisms are living, a couple of kilometers underground. On Earth,” he reminded me, “there are microbes growing four kilometers underground.”
As we parted, David McKay insisted, “Our critics have proved nothing. Our research has defeated each and every one of their arguments, and the case for ancient life on Mars is now stronger than ever.”
Nine months after our meeting, McKay made his latest findings public at the 1999 Lunar and Planetary Science Conference in Houston; his announcement added to the controversy and ensured that the debate surrounding fossilized Martian bacteria would continue for years. To his way of thinking, there were now two meteorites from Mars bearing evidence of fossilized bacteria, ALH 84001 and the newcomer, from Nakhla, Egypt. His detractors claimed his analysis of the newer meteorite, Nakhla, compounded the errors he had made in his analysis of the first, but his supporters insisted it offered compelling confirmation of extraterrestrial life.
3 GROUND TRUTH
To reach the Jet Propulsion Laboratory, you take the freeway to Pasadena and get off at the Oak Grove Exit, then follow Oak Grove as it winds gently toward the mountains through the luxuriant landscape. You feel the smog settle on your chest as you go. There’s no suggestion of high technology in the area, just a somnolent Southern California suburb, lush, green, and slightly sullen. As you sense the end of the road approaching, you assess the looming mountains, but there’s still no sign of JPL, and you begin to wonder what gives. JPL isn’t exactly off-limits, but it’s not easily accessible, either. It will be found only by those who put some thought into looking for it. You think you’re finally there when several large white modern structures appear on the left, but as you drive up to them, you realize it’s a local high school, and then, just ahead, there’s a gate and a guardhouse, and that, at last, is JPL.
People arrive for work early. By 7:30 AM, the parking lot is filled with Hondas and Fords and Nissans and Tauruses – nothing fancy, except the odd Corvette. Employees quietly fan out across the campus and go to work. The buildings at JPL are boxy, functional, crisp. Within its offices, there are the same horrible green plants you see everywhere at NASA, at headquarters or the Johnson Space Center in Houston. Once you’re indoors, you can forget all about Southern California; you might as well be in Washington or Florida; it’s NASA-land.
Despite its innocuous location, JPL is among the world’s leading centers for spacecraft engineering and development. Started in 1936 as the Guggenheim Aeronautical Laboratory at the California Institute of Technology, JPL is now run jointly by NASA and Caltech. In the early days, there were just a few people on hand, including Frank Malina, a rocket enthusiast, and Theodore von Kármán, an influential Caltech professor. The lab barely survived the Depression, but it got a boost during World War II for experiments in rocketry. During the fifties, JPL developed a satellite that, according to legend, could have beaten Sputnik into orbit by a few months and irrevocably changed the space race – if it had been launched. Throughout the sixties, JPL solidified its reputation as the place for robotics – unmanned spacecraft destined for the moon and the planets – but it lacked the high profile of the Johnson Space Center in Houston or the Kennedy Space Center in Florida.
All that changed with the advent of the new Mars program in 1992, when a new generation of employees began streaming into JPL, reinvigorating the place. Unlike many of the old timers, they hadn’t come out of the military or the aerospace industry, they were just out of grad school, and had grown up watching the space program on television. They were young, and they weren’t burdened by the past. The men wore earrings and pony tails instead of military buzz cuts, and tie-dyed t-shirts replaced white polyester short-sleeve button-down shirts and narrow black ties. But that was just the men. Many of the new recruits were women, and among them was Jennifer Harris.
Growing up on her family’s farm in Fostoria, Ohio, Jennifer never expected to explore Mars or to become a flight manager for a Mars mission. She wanted to be a concert pianist. She played the piano, the saxophone, marimbas, bassoon, trumpet, tuba; she was a one-woman band. On the other hand, she loved math and competed successfully in county-wide math competitions. Astrophysics excited her imagination, especially black holes; she loved just thinking about them. In the summer before her senior year in high school, she went to music camp, where she realized that her survival as a concert pianist would depend on her ability to practice every waking moment, and she wasn’t sure that was what she wanted to do with her life. She also wanted to travel, to meet people; she was even thinking of becoming a missionary. When MIT accepted her, she went into a mild state of shock. Eventually, she chose to major in Aerospace Engineering – partly because it sounded like the coolest thing she could do and partly because her father had tested missiles for NASA when he was younger, and she had come of age hearing his tales of countdowns, halts, and explosions. Or maybe the picture of a rocket on a wall in the den of her home influenced her decision. After graduation, she went to work for the Jet Propulsion Laboratory.
Even after she arrived at JPL, Jennifer was restless. They were designing spacecraft on spec, hoping to get funding from Congress, and most projects never did. If a project actually received a green light, the lead time was awfully long. As she toiled away at her subsystems, she couldn’t see where her little cog fit into the machine, or if there even was a machine. She began to ask herself, “Is this all there is?”
She was single and didn’t have any serious ties to Pasadena or JPL. She chose to take a leave of absence, without assurance that a job would be waiting for her when she returned, if she returned. She still wanted to see the world and meet people, so she decided to do missionary work in Russia. She was assigned to Sevastapol, in the Crimea, near the Black Sea, where the conditions were unbelievably grim. There was no hot water, and they lived in cement buildings that were always cold and damp. A lot of the population were flat-out atheists. The economic situation was horrendous. She was paid about $30 a week, which made her among the wealthiest citizens of the town. Everyone around her was subsisting in a barter economy, using coupons instead of cash; one Snickers bar, for instance, cost 2,000 coupons. She and her friends based everything on the cost of a Snickers bar, but that didn’t help keep track of finances, because the inflation was incredible. Pretty soon that Snickers bar cost 8,000 coupons, then 16,000. People who had saved throughout their entire lives lost their fortunes overnight when the ruble crashed.
At times she wondered what kind of space program the Russians could possibly mount under these conditions. She had to wonder how they got anything done. As if the Russians’ pervasive fatalism wasn’t enough, there was the corruption, another thing she hadn’t been exposed to back at MIT and JPL and the family farm. She knew evil when she saw it, though, and it seemed to her that Russia, or at least her speck of it, was basically run by the Mafia, the politicians, and the church, all in bed together. After a while, she wondered if she was meant to be doing missionary work, if it was really the best use of her abilities. Was this what God wanted her to do? Was this what she wanted to do? She had to say honestly that the answer was no, her education was going to waste here. When her tour of duty was over, she left Russia to wander around Europe.
One day, she sent a postcard to a friend at JPL to say she would be back in a few months. “Do you have any jobs?” she asked, knowing the answer was very much in doubt. The day she arrived back in Ohio, JPL called to say they had a job for her, a good job, if she wanted it, but she would have to make a decision that day or the next. The job opening was on the new Pathfinder project, the next spacecraft to go to Mars. She said she’d take it. Jennifer was fairly skeptical about Pathfinder, but so was JPL. “A lot of people thought it would never work. There were so many things that could go wrong, especially with the Mars environment.” Her new job didn’t seem to have official status at JPL. Even the official Mars program people kept their distance. The development of Pathfinder struck her as a skunkworks, basically. She knew what that meant: if it wasn’t working, they could take it out and shoot it and bury it and no one would be the wiser.
The nature of her job changed as the mission went along. She began by working on software, “but the neat thing about Pathfinder was that once you took a job, it was sort of a ‘where-do-you-fit-in?’ type of thing. People didn’t say, ‘That’s not your job, stay out of there.’ They allowed you to move around, so I ended up doing more integration and testing in the early stages than operations. People were always given the opportunity to move over the borders and learn more and do more.” This open-ended, go-wherever-you-fit-in approach was something very new at NASA, and at JPL, which functioned along rigid, bureaucratic lines of command. The problem with the traditional structure was that if one element was delayed, or failed, or went awry, it brought the entire system to a halt. It became accepted practice for missions to slip several years. People were confined to narrowly defined jobs, and many of their talents and interests went untapped, because they had only a single task to perform. That paradigm didn’t apply to Pathfinder. Things were more flexible. It actually was faster and better and cheaper. This was all new, and very un-NASA.
Not everyone at JPL took to this open-ended approach, but Jennifer did. She became more confident in her various roles, accustomed to change. After her experiences in Russia, she knew not to overreact to situations and to plug along until she found a solution or failed miserably. In time she developed an informal network of specialists and advisors she could trust, her go-to people. The Pathfinder cradle-to-grave approach helped a lot. People came on board at the beginning, when the hardware was delivered, and they stayed all the way through to the end of operations. On the typical NASA mission, the person responsible for delivering the hardware would say, “I’ve delivered my hardware on time,” and walk away. If the hardware happened to be a camera, and it took pictures, they felt they had achieved their goal. They didn’t care if it was impossible to operate, or if it didn’t get the right pictures. But if you worked on Pathfinder, you had to undergo a mental shift. If you designed your component incorrectly, if it was difficult to test or to operate, it was still your problem.
It was difficult to explain the new thinking, Jennifer realized. You had to experience it for yourself, and then it could make a huge impact. You would become committed to the ultimate goal, whatever it was. In Pathfinder, the goal was to get to Mars quickly and cheaply, and to get a rover to function on the Martian terrain. Things worked in a sort of non-systematic way because people attacked problems where they saw them. Eventually, they generated procedures, and she wrote the documentation, but this was not a document-heavy mission, like most NASA missions. She sat down with a couple of other people, and they asked, “What are the most likely contingencies? What’s our nominal plan at the big-picture level?” She realized this could be a wonderful opportunity to participate in the exploration of space, and that idea pleased her greatly. “I feel like God has blessed me in my career,” she once wrote, “and I would like to glorify Him by exploring His incredible creation.” So the missionary had a new mission, but even as a scientist, especially as a scientist, she still devoted herself to God.
The Pathfinder mission originated in a speech given by President George Bush in 1989 to commemorate the twentieth anniversary of men – American men! – landing on the moon. NASA was in the doldrums at the time; and the occasion of the speech seemed to point up how little it had done since the halcyon days of Apollo. The Challenger disaster, which occurred more than three years before the anniversary, still loomed; when people thought of NASA, they didn’t visualize Neil Armstrong jumping onto the surface of the moon, they thought of the faces of the parents of Christa McAuliffe, the school teacher who rode aboard the Space Shuttle, looking in disbelief at the Y trail left in the sky by the catastrophic explosion.
Along came George Bush, discussing the future of space exploration. The demoralized NASA contingent could scarcely believe what they heard. Did the President mention “the permanent settlement of space”? Yes, he did. Did he also say it was time to travel “back to the moon, back to the future, and this time back to stay”? Indeed, he said that, as well. But surely he could not have said, “And then, a journey into tomorrow, a journey to another planet: a manned mission to Mars.” Yes! The President said that, too. Mars. The NASA bureaucrats began to ask themselves: how much was all this going to cost? No one thought you could go back to the moon and on to Mars for under 400 billion dollars; the tasks might require twice that amount. NASA’s annual budget at the time was around 13 billion. Where would the money come from? Interestingly, few doubted that the technology existed to send people to Mars, or that it could be developed quickly; if NASA had the money, they could get the job done.
George Bush’s remarks evoked John Kennedy’s famous speech in which he charged NASA with the duty of sending men to the moon. Without realizing it, Bush tapped into the agency’s other obsession, reaching Mars, an obsession that had begun in the mind of its ace rocket engineer, Wernher von Braun, during World War II. Von Braun, a member of the Nazi party, and a favorite of Hitler’s, had helped to design the V-2 missile. When he became disillusioned with the Nazi war machine, the Gestapo arrested him and sent him to jail. In his cell, he turned his attention to interplanetary travel, and Mars in particular. And it was in these strange and harsh circumstances that the kernel of what would become the American effort to explore Mars was born. In May 1945, von Braun and over a hundred other German rocket scientists surrendered to the Allies. They were swiftly transplanted to New Mexico to continue their work on rockets, this time for the United States. The German V-2 became the prototype of a new generation of American missiles, and on the strength of his engineering accomplishments for the Nazis, von Braun quickly established himself as the chief architect of the American space program’s booster rockets during the 1950s and 1960s; his designs were responsible for getting American men to the moon.