The Rock From Mars (26 page)

As government committees worked out the new rules, several researchers charged that NASA was trying to limit studies of the rock to the “pro-life” side. McKay, who continued to seek outside experts to help with the group’s work on the rock, inadvertently aggravated this sore spot by dispatching some of the team’s own specimens to selected colleagues without going through proper channels. His NASA bosses reprimanded him.

Not long after the McKay team’s paper came out, there was a party at Johnson Space Center to celebrate. Dave McKay was making the rounds, shaking hands, when he spotted colleague Allan Treiman, of the neighboring Lunar and Planetary Institute. A meteorite specialist, Treiman was one of those who had been interviewed on TV several times about the McKay team’s findings. He and McKay had worked closely together a few years earlier and had become friendly. McKay started outlining ways he thought Treiman could help with the next phases of research on the meteorite. Treiman reacted harshly. He had not yet “bought into” the Mars rock claims, had not volunteered to work on the project, and he thought McKay was being a little presumptuous. “I’m just like a little kid,” he would say later. “When someone tells me to do something, I sort of resist it. . . . Dave didn’t like it when I didn’t sign on with him, and that was sort of the beginning of a downward trend in our relationship.”

Treiman had been nursing a resentment about work he had done on the Allan Hills rock himself a couple of years earlier, with Kathie Thomas-Keprta serving as his sherpa on the transmission electron microscope in Building 31. (It was one of her duties to make sure people who came in to use the microscope didn’t push the wrong button and blow the system up.) Treiman was fascinated by the same carbonate globules that had first attracted Chris Romanek, and particularly the little magnetic crystals inside them, but he was interested in them from a purely inorganic standpoint. Like many people, he was interested in the history of water on Mars; he wanted to understand the compositions of the solutions that might have deposited those minerals, because they were the only traces of what water on Mars was like. As he and Kathie Thomas-Keprta worked at the microscope together, he freely discussed his ideas about what they were seeing, and shared his results.

When he learned later from a third party that she had been secretly studying the same features but had never offered to collaborate, Treiman suspected that she had deviously used his work for her own purposes. He came to regard the McKay core group as ingrown and isolated. But he never confronted Thomas-Keprta about any of this.

Instead of acceding to McKay’s wishes that he join the research, Treiman decided to start a Web site that took a neutral position on the controversy and provided running updates describing the main lines of argument. He was inspired by a stockbroker he knew who had said he didn’t care if the market went up or down so long as people bought and sold stocks. As he would say later, “I figured, since I didn’t know which way I was supposed to go on this, the way I could benefit me and the institute around me was to try to be in the middle.”

After his 1996 announcement, McKay set up a series of weekly seminars to talk about Mars, astrobiology, the origins of life, and related topics. People were invited to come one weekday afternoon and give talks in the little conference room in Building 31. But the gatherings died out after a couple of months, Treiman said, and he thought it was because the McKay group was not sharing the inside information that their colleagues were intensely interested in—their ongoing work on
the
meteorite.

In early 1997, Treiman got an angry call from McKay. An intern had apparently told one of McKay’s daughters about negative comments Treiman had made about the McKay group’s claims. “I don’t remember saying that stuff, Dave,” Treiman answered. “You know I have problems with your work, but I don’t remember saying any of that in particular.”

McKay himself soon decided that he had gotten overly defensive in the combative months following the announcement, to the detriment of his real work. He regretted it and started trying to shift his energies back to the laboratory, to generating more data on the rock.

Technically, a person isn’t supposed to get emotionally vested in a particular outcome. Science is an enterprise in which reasonable people can weigh their disagreements together as they seek truth. The textbook version of the deal is, you propose a hypothesis, which leads to a prediction, which is then put through “risky” tests by experiment. The outcome will confirm or refute your hypothesis. Or at least it will appear to, until an exception or complication crops up. Failure is always an option. Controversy and failure can be as valuable (to the process if not to the individual) as triumph. This is how humans, with their powerful, “self”-conscious minds, learn new things; it is how they sort reality from myth, rumor, lies, and speculation.

But scientists obviously do care, some passionately. To sort through the chaotic jumble of “data” and come up with a useful picture of nature takes imagination, and an investment of individual spirit. “About thirty years ago there was much talk that geologists ought only to observe and not theorize,” Darwin wrote in an 1861 letter to one of his prominent defenders, a British politician and economist, “and I well remember someone saying that at this rate a man might as well go into a gravel-pit and count the pebbles and describe the colors. How odd it is that anyone should not see that all observation must be for or against some view if it is to be of any service!”

Some people thought that for cases such as the Mars rock controversy, another model for scientific inquiry was preferable to the textbook one. Carol Cleland of the University of Colorado, a specialist in the philosophy of science, argued that “some of the controversy over ALH84001 derives from a misguided insistence that all research conform to experimental practice.” She decided to teach the case in her classroom.

“It just drove me nuts when the Allan Hills meteorite news broke,” Cleland would say later, “and people just lashed out” at the McKay group on grounds “they hadn’t ‘proved’ their hypothesis. Well, please. We haven’t proved E = MC
²
[Einstein’s famous equation], either. I mean there’s no such thing as proof of this kind in science.”

Cleland considers the traditional approach generally ill suited for certain fields, such as paleontology, archaeology, astrophysics, and planetary science. They require a different—and, in her view, equally effective—way of confirming a hypothesis, called the
historical
method. Science is not a monolith, but ideally employs different methods based on the different ways that nature is physically put together.

While the classic experimental approach looks
forward
in time (making predictions), historical research looks
backward
in time. Experimental researchers are interested in hypotheses about regularities, about the universal, the general: All copper expands when heated. (Not under all circumstances.) All swans are white. (Until you find the black ones.) E = MC
²
. Historical researchers, by contrast, focus on a particular event, such as what caused the extinction of the dinosaurs on Earth. They aren’t out to prove that all meteorite impacts cause extinctions, but to investigate whether a particular impact caused a particular extinction.

Instead of a single hypothesis to be tested, historical researchers propose multiple hypotheses to account for traces and clues from past events. They then hunt for a key piece of evidence—a “smoking gun”—that will point uniquely to one of the competing hypotheses as the best explanation. (A few decades ago, some fifteen hypotheses had been put forward to account for the dinosaur extinction, including disease, climate change, an exploding star, and the one that was finally accepted after many years, a cataclysmic meteorite impact.)

Cleland likens historical researchers to Sherlock Holmes, stationed in the present, trying to re-create events in the past. It is hard to erase all traces of an event once it has occurred; this is the basis of good detective work. It is difficult to commit the perfect crime. There are many traces of the past in the present, and you only need a tiny portion of those to infer the existence of a past event.

What initially happened in the case of the meteorite, Cleland argues, was that people hit the McKay group with criticisms from the vantage point of their own different disciplines. “The critics were complaining, ‘Oh, you haven’t tried to falsify it,’ or ‘you haven’t tried to prove it.’ All of this was to hit them with inappropriate methodology, . . . [with] claims that they should do something that I would argue would be irrational for them to do.”

Some scientists were mortified by the whole spectacle. Others were convinced that the public had been exposed to the conflict at too early a stage. “Some [people] might draw the conclusion that scientists are morons who can’t make up their minds,” said the geologist Ralph Harvey. Some scientists, alarmed at the image this furor might be conveying to the public, thought the press reports exaggerated the “mudslinging” nature of the debate.

Others thought the case was a dandy demonstration of scientific give-and-take at its most passionate, and for stakes that could not be much higher. NASA funded not only the McKay group but most of their opposition, and no one was penalized for a given stand on the matter. For better or worse, the scientific process was on display, warts and all.

At the height of the controversy, a single pinprick-sized carbonate globule from the meteorite could easily have fetched $10,000, one meteorite specialist estimated. However, the curators took extraordinary precautions to make sure that no piece of the rock ever reached the market.

The controversy soon had as many snarling, snaking heads as Medusa. And, in the course of the protracted battle now begun, it would speed the process in which the search for life
beyond
Earth increasingly intertwined itself with the struggle to understand the origins of life
on
Earth.

The Mars rock would generate scores of papers and lead researchers around the globe on a years-long descent deeper and deeper into the microscopic recesses of the rock’s ancient landscape. The investigators would mobilize an arsenal of the world’s most advanced technologies to the task, and enlist humankind’s accumulating knowledge in such varied specialties as how atomic nuclei decay, how plastics behave, the history of magnetism on Mars, how bacteria on Earth find nutrients in murky waters, bacterial immunology, properties of impurities in Antarctic ice melt, how various minerals precipitate out of water as acidity goes up or down, and the minimum requirements of a living cell. It would be difficult for any single individual to be truly expert in all the diverse precincts of knowledge that the puzzle in that one fist-sized rock brought into play.

Throughout the bloody aftermath, McKay and his group would take particular comfort in one thing: no one—not the most truculent of adversaries—ever questioned the validity of the data they had published. It was the audacity of their interpretation—not their evidence—that had opened the can of Martian worms.

CHAPTER ELEVEN

EXPLORATIONS

O
N THE CHILL
, drizzly afternoon of December 11, 1996, David McKay again found himself in Washington, D.C., this time seated at a big table with the vice president of the United States, several senior government officials, and almost two dozen prominent scientists, theologians, and educators.

The reserved scientist from Texas felt a mixture of pride and amazement. These accomplished people had gathered here at the White House as a result of his group’s work on the rock. He would never have imagined such a thing two years earlier, when he, Gibson, Romanek, and Thomas-Keprta had agreed to begin their collaboration. In fact, they were all still feeling frankly stunned by the intensity and breadth of the public reaction.

Now McKay was trying to soak up every detail, so he could give his wife a full report that night when he got home to their woodsy cul-de-sac.

The belligerencies triggered four months ago, the day he’d sat in the bright lights on the NASA stage, showed no signs of abating. Nevertheless, the Clinton administration had decided to go ahead and stamp the White House imprimatur on the tricky topic of extraterrestrial life.

At last, it seemed that nature was pointing the way around the giggle factor. The McKay team, in tandem with the burgeoning insights about Earth’s most extreme life-forms and the proliferating discoveries of planets around other stars, had put legitimate research questions on the table. In Washington, this meant that E.T., at least in a primitive, microscopic, and still hypothetical form, might be politically rehabilitated where it really counted—in the federal budget.

Many person-hours of planning had gone into today’s closed gathering. A scientific workshop, university symposium, and other events had laid the groundwork. Officials at the White House science office, the National Academy of Sciences (and its National Research Council), and NASA had carefully pruned the invitation list. They had written and rewritten a suggested script for the vice president.

After introductions and pleasantries, Gore laid down a ground rule: “Let’s assume for the sake of discussion that David McKay is correct.”

That makes it nice, McKay thought. At least here, in this heady air, he didn’t have to feel defensive. In fact, this was turning out to be fun. Somebody at the table did eventually ask McKay how sure he was about the claims, and what the team intended to do next. McKay responded that he was “reasonably sure,” but he emphasized once again that there was “an awful lot of work yet to be done.”

The group steered clear of budget talk, per se. They focused instead on the softer societal, cultural, and religious, as well as scientific, issues exposed by the claims of possible extraterrestrial life and other recent scientific developments, and on the research opportunities that might now be seized.

Seated at the head of the table, the vice president was flanked on his left by John Gibbons, the White House science adviser, and on his right by NASA administrator Dan Goldin.

The other men and women around the table included leading lights from the fields of atmospheric chemistry, origins of life, biogenesis of membranes, planetary systems, planetary geoscience, evolution of the universe, biological complexity, stars, and bacteria.

One of the better-known participants was the evolutionary biologist Stephen Jay Gould, the author of almost twenty books. His celebrity status was approaching that of Carl Sagan and the other leading scientist celebrity, Stephen Hawking. (In 1982, Gould had appeared on the cover of
Newsweek,
and in 1997, he would attain the ultimate in cachet with a cameo on TV’s
The Simpsons.
)

Gore asked him what would be the minimum consequence if the McKay claim turned out to be true. Gould responded that if life had sprung up on only one world and been transported to the other, if Earth had “seeded” Mars or vice versa, that would say little about the potential abundance of life in the broader cosmos. It would mean scientists still had essentially only one case.

Gould was delighted with the news about the Mars rock. He suspected that the “fossils” were inorganic, not biological, though he wouldn’t bet heavily either way. He found the McKay group’s
Science
paper to be well written and properly cautious.

The news had broken about the time Gould’s book
Full House: The Spread of Excellence from Plato to Darwin
was coming off the presses. In it, he argued that the human species was not some glorious peak in the evolutionary march from simplicity to complexity. Humanity was, rather, one accidental variation in a realm of variation. Bacteria and other microscopic life-forms had been the genesis life-form, and they had never gone away. The McKay group’s line of inquiry, whether their interpretation held up or not, was in harmony with this theme.

Two years earlier, in a talk at George Washington University, Gould had summed up one of the credos of exobiology (soon to be subsumed in the new field of astrobiology) when he told the audience that all life on Earth was the product of one single experiment, and we can’t fully understand how that experiment proceeded “until we find another experiment independent from Earthly life.” He concluded, “That other experiment is as close to a Holy Grail for biology as anything else we could conceptualize or ever know or find.”

Gould would echo that sentiment after the vice president’s session, telling reporters that if life on Earth was found not to be unique, “the implications just cascade. They’re just enormous.”

Gore then asked astronomer-historian Steven Dick, who had just published
The Biological Universe,
about the other extreme—what would be the maximum consequences of life on Mars. Aside from the profound implication that we might not be alone in the universe, Dick said, what was at stake was humanity’s worldview and the possibility of constructing a universal biology in the same way that Kepler, Galileo, Newton, and their successors had demonstrated a universal physics. “We are trying to determine whether the ultimate outcome of cosmic evolution is merely planets, stars, and galaxies, or life, mind, and intelligence.”

The meeting planners had originally assumed the session would focus solely on the scientific questions, but President Clinton, because of his interest in religion, had asked specifically that the group address theological questions and the interplay of science and religion. How, for instance, would the discovery of life beyond Earth affect humanity’s self-image, and its image of God? What were the views of the world’s major religions regarding the possibility of extraterrestrial life? Was there a danger in this realm—as in the burgeoning research on the human genome—of offending vast taxpayer blocs?

Religious leaders had been invited, Goldin would say later, because “it’s crucial that we . . . have broad consultation with the American people. When you have science—free-flying science—funded by tax dollars, you want to avoid crossing ethical boundaries.”

His point was punctuated by the virulent reactions in some religious circles. Richard Zare, for one, after talking about the meteorite on ABC’s
Nightline
and other TV programs, had heard from all manner of people, including UFOlogists, but was most unsettled by the angry fundamentalists. In these calls, including some from Europe, people screamed at him about the religious implications. His story did not match what was in the Bible. Internet chat rooms took up the banner. As a protective measure, Zarelab had taken down its Web site, along with information about how to contact Zare’s office. Things stayed scary for about a month before the hubbub subsided.

But the public outpouring around the world also included more thoughtful musings, often by prominent people, on the theological and philosophical implications of extraterrestrial life. There was a sense that the world’s religions were flexible on the issue.

The White House discussion mirrored the broader discourse. Catholic theologian John Minogue, president of De Paul University and an obstetrician-gynecologist, said there was considerable support for the notion that science and religion could coexist harmoniously. Religion was rooted and stable. Science by its very definition disturbed the status quo, pushed the envelope. “We need both,” he said.

One absence was keenly felt in the room that day. Just before the vice president’s session, Carl Sagan had informed Goldin that he would be unable to attend. His hair gone, his body withered, Sagan was losing his battle with the bone-marrow disease. He would die nine days later, on December 20, at a cancer research center in Seattle.

Sagan was arguably the most effective champion of the scientific hunt for extraterrestrial life and had galloped to its rescue on numerous occasions. Now he managed to express himself once again on the issue at hand. He had sent White House science adviser Gibbons and NASA chief space scientist Huntress a letter offering suggestions as to how NASA might best follow up on what he called its “extraordinary accomplishments” that year, which had brought the space agency “a degree of public support it has not enjoyed in years.”

He alluded indirectly to the giggle factor that had fueled Congressional objections to SETI (the Search for Extraterrestrial Intelligence) and urged scientists to try again to revive the program. “The putative finding of fossil microorganisms on Mars and what is beginning to look like abundant planets around other stars surely enhances the plausibility of extraterrestrial intelligence,” he wrote. “If such intelligence were found, it would be a turning point in human history. If after a comprehensive search program it were not found, it would calibrate something of the rarity and preciousness of intelligent life—information well worth having also.”

In the public interest, Sagan urged that the report on these developments “be thoroughly de-jargonized. . . . Furthermore, we should be sensitive to arguments that strike the lay reader as implausible. For example, how could we possibly know that a rock found on the Antarctic ice comes from Mars? To the novice this seems the wildest guess. A paragraph that discusses the definition of an isotope and the Viking findings on the composition of the Martian atmosphere is an investment well spent.”

Sagan had always believed that, in tandem with the human advance toward new knowledge, it was important to provide the public with a travelogue about the journey—and in clear, simple language. This business of popularizing science had made Sagan wealthy, famous, and admired in the general populace—but a pariah among many of his colleagues.

In his early years, Sagan had churned out a torrent of important research that interwove astronomy, biology, chemistry, and earth sciences. He eventually garnered eighteen honorary doctorates and over sixty awards or medals, including a Pulitzer and three Emmys. Yet Sagan had been denied tenure at Harvard, and in 1992, in a move Sagan partisans attributed to professional envy, the National Academy of Sciences, the nation’s most prestigious scientific organization, had rebuffed an attempt to get Sagan voted in as a member.

Over the years, some people had criticized him for drifting further and further from active research as he gave in to the seductions of celebrity, or they’d murmured that he had become a prima donna with the ego of a rock star, or had tainted his career with his political activism. Some considered it frivolous and counterproductive for a scientist like Sagan to spend time trying to “dumb down” their way of speaking among themselves—an argot designed to be extremely detailed and precise—to benefit the lay public.

For citizens with a curiosity about science, his death would leave a void, and a long search for another approaching his rare mix of intellect, skills, charisma, and stature.

In one of his final essays, echoing Schopf’s echo of his own words, Sagan cautioned that “the evidence for life on Mars is not yet extraordinary enough.” But he added that the McKay team’s discoveries in the rock opened up the field of Martian exobiology.

Arguably, on this wintry day in December 1996—as David McKay’s recent experiences illustrated—science had reached a state where studies of the most remote corners of the galaxy, and of the most humble ribbons of gas in space, and of the most unassuming flecks of dust or rock all constituted research on the same fundamental and deeply fascinating topic: the story of life—life on Earth and wherever it might be found. It was this sense that moved the McKay team along the unlikely track they had followed into the depths of the rock. It was the intellectual sea in which they swam.

A couple of weeks after the Mars rock burst into the headlines, a team of genetic researchers led by Craig Venter and based in Rockville, Maryland, just outside Washington, published in the same journal
—Science—
word of a stunning development for the understanding of terrestrial life: in the culmination of some two decades of work, they had confirmed the existence of a third major domain of life.

They had done this by sequencing the genes of methane-belching microorganisms that dwell on the floor of the Pacific, tucked into the crevices of the hot-water vents that spew boiling-hot, mineral-rich fluids into the cold sea. The organisms thrive in the extreme heat without oxygen or direct sunlight and do not need organic carbon as an energy source.

The microbes called Archaea joined the other two major life domains: the bacteria (prokaryotes) and the more complex life-forms (eukaryotes), including plants, animals, and humans. “We were astounded to find that two-thirds of the [archaea] genes do not look like anything we’ve ever seen in biology before,” Venter reported, adding that the research showed “how little we know about life on this planet.”

The accumulating discoveries about extreme-loving microbes reinforced speculations that life might once have sprung up, might even exist today, in hidden pockets on Mars or in some other extraterrestrial oasis not yet dreamed of. And NASA’s Galileo spacecraft, in orbit around Jupiter, had pumped up the excitement by taking provocative photographs of the Jovian moon Europa that showed evidence of slushy ice or liquid water in a vast subsurface ocean there—another potential haven for life.