The Rock From Mars (25 page)

The opening of a window on the mysterious Precambrian revealed that, as Schopf liked to put it, “for three billion years, this was a planet of pond scum!” And “the modern world—the familiar fauna and flora of air-breathers and oxygen producers, the eaters and the eatees—is merely a scaled up version of a microbial menagerie billions of years old.”

With that insight, plus the revelations of “extremophiles” thriving in all sorts of toxic nooks all over the planet, at the approach of the millennium the evidence seemed overwhelming that the most conspicuous and enduring feature of terrestrial life was its stable microbial population. Just as Earth had been displaced from the center of the universe, the proudly big-brained human species was in some ways being dislodged from its position of dominance in the realm of living things.

When he took NASA’s stage as devil’s advocate that day in August 1996, Schopf had the authority born of those 26 years in the paleo trenches. He knew as well as anyone how titanically tough it was to identify life in ancient rock.

When challenged or annoyed, Schopf could be intimidatingly forceful, his voice rising with the roar of a freshening gale. But he was also capable of a folksy, professorial charm, and it was in this vein that he delivered his assessments of the McKay group’s hypothesis that day.

Schopf had an undeniable advantage over McKay and his Houston-based collaborators (though not Zare) in terms of prestige, credentials, and funding. He was Goliath to McKay’s David. As Schopf was well aware, history had shown that smart and powerful people could be wrong—even determinedly, stubbornly, persistently wrong—and that people lacking in influence could be right. The process of learning something new could be skewed in any direction by a player’s status and ability to sway others.

But in the end, advances in knowledge did not rest for long on power, influence, charisma, or credentials, and they did not depend on majority rule. All of the players in the current drama shared the sacred creed: that in the end, the slow accumulation of evidence would reveal the truth.

Schopf’s comments generated wide praise, and the heartfelt appreciation of Goldin, Huntress, and others in the top ranks of NASA. They knew he had been reluctant to get involved with the Mars rock, but he provided the balance they considered essential.

The photogenic “worms”—the putative microfossils—became the stars of the media coverage following the NASA press conference. In a society that was more and more visually oriented, a good picture was worth a thousand sound bites.

But Schopf stated clearly that a provocative shape was not nearly enough. To be convinced that the wiggly forms in the Mars rock were indeed fossil remnants of dead bacteria, he required nothing less than what he himself had found in the Apex chert of Australia, with his record-setting fossils. Among other things, he wanted to see rounded cell walls made of organic material. And yet, Schopf noted, the McKay team had included in their seven-page technical article only four sentences on the fossil-like features, with a single reference to their resemblance to terrestrial microorganisms.

The size problem was a deal breaker, in Schopf’s view. He knew, of course, about the controversial evidence on Earth of so-called nanobacteria, which had influenced Chris Romanek’s early explorations of the Mars rock. For many microbiologists, however, these entities were about as plausible as Bigfoot. Schopf was among many who questioned whether anything that size—Martian or terrestrial—could contain even the most rudimentary cellular machinery required for life as we know it.

The basic cell—the smallest unit of matter that scientists considered alive—had to house plenty of water, a set of instructions (genes), something to carry out life functions (proteins), and something to manufacture the proteins (ribosomes).

A cell was like a little room, or a capsule. If the Martian “fossils” had ever been alive, they would have needed some kind of wall to separate their chemistry from the environment in which they lived. This was a fundamental feature in all known forms of life. But the total breadth of some of the proposed Mars “organisms” was less than that of the simplest known bacterial cell
wall.
They were smaller than any bacteria whose existence had been confirmed—actually a million times smaller in volume than a typical bacterium and more like bits of cellular machinery (such as a ribosome).

Schopf’s smiling but unsparing rebuttal set the tone for much of the reaction among scientists—as it was meant to do. Many repeated Schopf’s unassailable admonition about the need, in a case like this, for “extraordinary proof.”

But the aftermath was more complicated than that.

The McKay team was caught completely off guard by the sheer fury of the challenges from many colleagues. They were staggered by the lacing of bitterness, of sheer personal vitriol.

The more extraordinary the claim, the more certain it was that the combatants’ full range of sensibilities would be engaged: the constellation of fears, resentments, and rivalries, the friendships and loyalties among individuals and institutions, the native ambitions, dogmatic beliefs, sense of cultural and financial pressures and tribal memories. A particular irritant was NASA’s reputation—born of Apollo—for mixing science, politics, and public relations to a high and, in the view of many, unhealthy degree.

“This is half-baked work that should not have been published,” declared Edward Anders, a leading authority on meteorites and the birth of the sun and planets and a veteran of the Apollo lunar-sample investigations. Anders had a lustrous track record on the very question at hand—prospecting for biological signs in meteorites.

In 1961, as students of meteorites were well aware, researchers in New York had announced a similar detection of possible life-forms, structures like “fossil algae,” in a meteorite. Their samples had come from a shower of carbon-rich meteorites—fragments from an asteroid, not Mars—that had fallen in the previous century near Orgueil, France. In 1961, as now, the announcement had caused a great hubbub in the press. Then, as now, skeptics had conducted their own analyses and refuted the claim. Anders, then at the University of Chicago, had produced a series of critical papers that played a crucial role in sinking the claim. A consensus had developed that the alien “fossils” were actually Earth contamination—some of it likely plain old terrestrial ragweed pollen.

This and other discredited claims constituted a flashing warning for others working the same terrain. It had certainly pulsed in the heads of David McKay and his collaborators as they’d checked and rechecked their work on the Allan Hills rock for two years, in preparation for going public.

Yet Anders felt compelled to disrupt his retirement in Switzerland. In an e-mail to McKay soon after the paper came out, Anders began with congratulations on “outstanding aspects of your work, especially your superb data and techniques.” Then he lambasted the team’s conclusions, alluded to the proposed nanofossils as “turd-like shapes,” and hammered away at the “distressingly biased” interpretations” and “illogic.”

Science
magazine published a toned-down version of this message. His words resonant with authority, Anders compared the McKay team’s claims with the 1961 case. “The Orgueil meteorite was bad data and bad interpretation. Now [with the McKay claims] we have good data and bad interpretation.” Summing up the McKay group’s various lines of evidence, he concluded, “Five maybes don’t make a certainty!”

Geologist Ralph Harvey, who had done his own studies of the Allan Hills rock, joined the ranks of the outspoken, lamenting that a premature claim of this nature could be a setback for space scientists of every stripe. “Every single person who has written a letter to the editor saying ‘We don’t need this dreck about space’ will say they were proven right if this [McKay] paper turns out to be wrong.”

Even if the McKay group turned out to be right, Harvey asserted, their claim had a political taint. “The fact that the president of the United States spoke out on their behalf in an election year, and that the head of NASA was known to be looking to build the case for Mars exploration, means this was science being used for a political end. It scares a lot of us, frankly.”

Harvey had recently become the National Science Foundation’s man in charge of the annual Antarctic meteorite hunts, the same program that put Robbie Score on the ice back in 1984 and made the current controversy possible. As Schopf mentioned at the NASA press conference in August, Harvey and colleagues had already published one paper at odds with McKay, indicating conditions on Mars too hot to accommodate life.

In the months after the August announcement, the debate got so acrimonious that
Newsweek
reported its descent to the level of “you ignorant slut!” (shorthand for the parody of supercilious talking heads made famous on NBC’s
Saturday Night Live
). Anonymous quotes—among the least admirable or credible features of journalism—flew in all directions. The magazine quoted one unnamed meteorite researcher as saying that the McKay team consisted of “an inferior group of people [who] are setting the agenda for others who have real science to perform.” Other anonymous missiles included:

•                  “He wouldn’t know the truth if it bit him.”

•                  “He wouldn’t know a meteorite if it hit him.”

•                  “I am appalled he is still in the business.”

Gibson, ever the most outspoken member of the McKay group, countered at one point that one of his critics, whom he didn’t name, “has been in this country for 32 years and hasn’t held a permanent job.”

NASA’s reputation as a scientific “entitlement agency” with a special mandate (which critics often lumped together with the Department of Energy in this regard) fed the flames. Some people, in political as well as scientific circles, loathed the agency’s approach to allocating scarce research funds—an approach established at its inception under the Cold War umbrella—because (despite recent efforts by administrator Goldin to change this) they so often saw NASA operating outside the true rigors of the merit-based, peer-review regimens of the scientific establishment.

A corollary concern wafted through the atmosphere in which the McKay team produced their claims. It flowed from the specter known as cold fusion—a “discovery” that had made big news in March 1989. Two chemists claimed they had invented a tabletop device that produced more energy than it consumed, by means of nuclear fusion occurring at “cold” room temperatures rather than at the multimillion-degree temperatures that exist where it goes on inside stars and hydrogen bombs. If valid, the work could have led to a form of cheap, abundant energy that would transform civilization. But the chemists had announced preliminary results of their experiment before any review by independent scientists—or before they even managed to reproduce their own results.

The event, staged in Utah, turned infamous when numerous outside scientists were likewise unable to duplicate the experiment. While a few true believers would press on with the research, the wider scientific community rapidly concluded that the chemists had made serious mistakes in the conduct and reporting of their experiment and had never seen the “amazing phenomenon” they’d claimed.

In that case, the process of testing and knocking down had worked—and worked fast. But the
way
it worked—the initial burst of high-profile news reports (albeit in most cases with appropriate caveats), including the covers of
Time
and
Newsweek,
followed by a highly visible reversal—felt embarrassing to many scientists. The higher the stakes, the greater the sting of collective humiliation. Spectacular blunders of the cold-fusion sort could lead the public to question the credibility of unrelated projects.

Now, amid the furor over the Mars rock, a lot of people mentioned their desire to avoid “another cold fusion”—even though the McKay group (unlike the cold-fusion chemists) had done appropriate checks on their own work and passed the tests of peer review. One meteorite expert told
Newsweek
that the intense bitterness stemmed from a “profound fear” by meteorite scientists “of what this might do to our field. We’re at the bottom of the pecking order in NASA’s budget, and people are concerned that if this turns out to be as stupid as cold fusion we’ll be out on the street.”

With the shades of cold fusion, the Orgueil “fossils,” and other misadventures, as well as NASA’s waywardness, haunting them, and with the added aggravation of having been caught off guard when the Mars rock announcement had escaped untimely into the public domain, many scientists were not in a mood to be charitable toward McKay and company.

At the time of the McKay group’s announcement, almost fifty laboratories around the world had pieces of the rock from Allan Hills. Quite apart from any possible signs of Martian life, the rock’s other unusual properties (the carbonate deposits, the fact that it was the oldest rock known from any planet, and so on) made it a hot item.

Once the McKay claims surfaced, many of these researchers, from San Diego to New Mexico to London, took their samples out for another look. One researcher was moved to open up his freezer, where he had stored a large amount of ice from Allan Hills, hack off a big chunk, and melt it down for testing as well.

McKay and his eight collaborators had spent more than two years refining and checking their analysis. Other scientists who had not already received samples of the rock were now starting from zero—at a time when getting a piece of the rock had suddenly become difficult. Some would have to wait months.

After the August announcement, the suddenly beleaguered interagency working group responsible for allocating pieces of the meteorite to interested scientists halted the distribution on grounds that the group needed time to consider the blizzard of requests and select the most promising ones. The group set out to develop a strategy for distributing the material while holding a significant portion in reserve for, say, ten years in the future when advanced instruments might clear up the mysteries.