The Rock From Mars (12 page)

Mittlefehldt and meteorite curator Marilyn Lindstrom had invited anybody who wanted to work on the rock to join a consortium and use Mittlefehldt’s samples. Because his general motivation was to learn, and in this case specifically to learn about Mars, Mittlefehldt preferred to disperse his samples among people he thought could do “something neat” with them.

This sharing would speed up the investigation. The ritual of request and response was ordinarily handled by a committee of meteorite gatekeepers from the Smithsonian, NASA, the National Science Foundation, and various universities. It could take months—even for those whose labs were right there in Building 31 where the meteorites were housed—to get a new allocation.

Curators typically shipped the samples in one of two forms: rough “chips”—essentially crumbs, or broken-off pieces—which could be shot with lasers, crushed, or otherwise destroyed, and “thin sections,” slices of rock mounted for microscopic study, which could be checked in and out of the repository like library books and used over and over.

In most cases, Mittlefehldt would grind up and homogenize a sample and give away to others “splits” of that material. An added benefit of this approach was that the researchers could compare and use one another’s results from the same sample.

This afternoon in the late summer of 1994, when Gibson and Romanek strolled down to McKay’s bright corner office, they sidled warily up to their topic. They were not about to admit the true nature of their speculation about the rock: that dancing coyly in the backs of their minds was the incredible possibility that they were peering at the first known signature of extraterrestrial life. They could just imagine McKay’s reaction.

Instead, they closed the door and spoke, gingerly. “Dave, look at this.” The visitors showed McKay Romanek’s pictures. Gibson mentioned Romanek’s limited expertise on the scanning electron microscope, which Romanek readily acknowledged. McKay had been in the dusty trenches with the thing for decades and knew firsthand all the techniques they needed in order to get the best possible pictures. He responded with equally guarded interest. “I’ve been thinking about looking at these carbonates, too. I think we really have something here.”

McKay had merely set out to chase his dust trail. But he found himself, like the others, distracted by these beguiling orange carbonates. They were everywhere in the fractured rock, some squashed flat like pancakes, some spherical. Almost like little Dalí moons. You could see them with your bare eyes.

The three men formed a pact: “Okay, we’ll work on it, but we won’t tell anybody about it.” Well, hardly anybody. They had created the nucleus of their secret society.

They wanted the search for answers to be on their own turf, so to speak. The trio had started thinking about the rock as a whole, a system, rather than as isolated crumbs under a microscope. They wanted to make sure they knew which part of the terrain they were studying. They had all been working with Duck Mittlefehldt’s samples. They needed their own piece of the rock.

Romanek had developed a rapport with Robbie Score, and she became a key contact for his dealings with her meteorite lab. He found her wonderfully friendly, and happy to answer his questions about how the curatorial facility worked, or to supply lists of rocks that might be useful, or to inform him how he and his collaborators could get more samples of that rock she had plucked off the ice in 1984.

One day, Romanek and McKay walked upstairs and entered the kitchen-like meteorite archives, where the mother rock rested inside its nitrogen cabinet. They went through the protocols—took the air shower, donned the surgeon’s cap and mask, and so forth. They intended to select exactly the chips they wanted from specific locations in the rock. There it sat: the mother rock with smaller pieces that had broken off, or been knocked off, and canisters containing grains of it, like sand.

Romanek had visited the mother rock several times since Duck Mittlefehldt had first introduced him to it. He’d seen it initially as two big chunks that seemed kind of glued together with all this crumbly material in the middle, like two small bricks cemented with mortar. He and his coworkers decided they wanted to study that place where the “mortar” was, because that was the zone with considerable fracturing and crumbling and milling of the parent rock material. (Curators would refer to this light-colored band, less than half an inch wide, or about a centimeter, as the “crushed zone.”) These traumas had most likely happened when something slammed into Mars near the rock’s native site, or in a marsquake. The two “bricks” of rock had actually rubbed up against each other and broken up. That was exactly the sort of place—full of cracks and crevices—where fluids would have moved through. And these fluids would have deposited the carbonates as they flowed through this rubble.

When the staff tried to saw the slab from the middle of the rock for Duck Mittlefehldt’s consortium, it broke apart at “a porous band of weakness.” He got the resulting pieces.

The curators used a numbering system for each piece that came off the mother rock. (The first sample was “01,” the second “02,” and so on.) They could, in theory, reconstruct the original rock, a more fortunate version of Humpty Dumpty, if they could recover all the pieces.

Few if any of the keepers of the rocks understood what Romanek and McKay were seeking on this foray. As the staff brought out sample batches, the visitors would put them underneath the microscope and say, “Look, we want pieces that look like this, with the little orange disks on them.”

McKay and Romanek sorted through roughly sixty-five bits and pieces. Their arms inside those black rubber gloves, they used the curators’ tweezers to pick out specific
grains.

Some people would later accuse the McKay group of getting special treatment that enabled them to look at the rock ahead of everybody else. But by the end of 1994, the curators had distributed samples from the rock to more than forty groups around the world. And it was not uncommon for researchers to venture into the meteorite lab to pick out specimens.

In due course, the official allocators approved Gibson’s request, and the new allotment arrived downstairs in its Teflon plastic wrapping. It was only a few grains. Two grams, a fraction of an ounce. The work the McKay group would do on the rock from late 1994 through the time they announced their findings to the world would be based on this iota.

Soon, this impromptu archipelago of Martian landscape was consuming more and more of their lives—days, nights, and weekends. Riding on beams of electrons and amplified light, they inspected the microscopic turf that would later turn into a geochemical Hamburger Hill—the first Martian battlefield.

CHAPTER FIVE

THE CONVERT

K
ATHIE
T
HOMAS SUSPECTED
that the three men had gone a little over the edge. She couldn’t believe what she was hearing, what she was seeing. She had been vaguely aware of some stealthy commotion over Duck Mittlefehldt’s Mars rock, but nothing had prepared her for the surreal proposition these guys had just put in front of her.

She was at work in her microscope lab this particular afternoon in mid-September 1994 when Everett Gibson appeared at her door. He invited her to walk down the hall to David McKay’s office for a chat with the two of them and Romanek. They sat around a big table in McKay’s corner office, daylight streaming through the windows on two sides. Romanek’s images of the rock were arrayed in front of Thomas.

At the time of this meeting (as Thomas would soon learn), barely a week had passed since the three men decided to collaborate in secret. McKay had asked Gibson and Romanek if he could bring Kathie Thomas in. They’d responded, in essence, sure, we don’t have a clue where this project is taking us, anyway. We could use the help.

The three men outlined what they had found so far in the rock, showed her the images, and then got to the point. McKay asked her to drop what she was doing and join their clandestine project. She heard David pose the question: “Could this be life in these carbonates? Could this be microbial life?”

These guys wanted her to help them look inside a rock for microscopic fossils of ancient Martians?!

McKay, she kept thinking, was usually sensible—known for his caution. She had worked for him for years; she respected him and thought she knew him. She knew Romanek as a coworker, and Gibson, too, though not as well. She wouldn’t have pegged any one of them as a nut.

The men were well aware that they had virtually no evidence. They knew their idea sounded far-fetched. They understood that Thomas thought they sounded “wacko.” But they were following an instinct, taking a creative leap based on a vivid sense of the natural world and its workings. Einstein, among others, had shown this to be a legitimate approach to advancing human knowledge—to dream up theoretical frameworks that extended well out beyond the hard data. But ultimately, they knew, the leap of imagination, in order to be validated, would have to come down in a foundation of evidence that would hold up under rigorous challenge and could be tested, and reproduced, in experiments conducted by others. That was how it worked.

The McKay team’s lack of such a foundation was a big reason, if not the main reason, they wanted to work in secret. They weren’t even telling Duck Mittlefehldt, who had brought the rock to Romanek’s attention.

Kathie Thomas was reluctant. She was in the midst of a project that had just begun to pay off for her. And within the last few months, she had barely emerged with her skin intact from a painful fracas over some startling results she had come up with. For some time now, people had been telling her
she
was crazy. She knew what it was like to be at the center of a skirmish, and she was not eager to jump into another. She told the three guys around the table that she would think about their proposition. She wanted to talk it over with her husband, Sean Keprta, who also worked at the space center. He was in charge of health and safety. They had met on the job.

She went home that night and told him about her day. She said she had serious misgivings about getting involved with this nutty-sounding hypothesis. Her husband pondered her dilemma. He said, “You know, if they’re not right about this, they need someone to keep them grounded. So you could go in with the attitude of proving them wrong. Then none of this foolishness will ever come out.”

Kathie Thomas would later explain that she had gone into this inquiry as “a
doubting
Thomas.”

An attractive, coltish blonde who favored jeans and sneakers, Thomas kept a doll propped on a shelf in her office: Paleontologist Barbie. As a girl growing up in the Midwest, she had been an ambitious student. She didn’t care for English, preferring to compete with the boys on “their” turf, science and math. She delighted in “setting the curve” for the class and credited a few crucial teachers for egging her on. She had a chemistry teacher who, even if she answered every question correctly on an exam, would give her a 99. Why not 100? she would ask. The response, which she remembers to this day, was “Until you know everything there is to know about the subject, you get a 99.” From her grown-up perspective, she thought that this had been a valuable (though frustrating) prod to keep her always learning, moving, improving.

She arrived at the space center in 1984, the year Robbie Score plucked the rock from the blue ice of Allan Hills. Like many of her colleagues, Thomas was not a NASA civil servant but a contract employee, working for an aerospace company that would become Lockheed-Martin. That meant living with one-year contracts and the possibility of getting sacked with little notice.

Thomas had not been trained as a geologist. Her specialty was in carbon chemistry, and that fit in perfectly with the work her new boss, David McKay, was doing at the time. More important, she had become skilled in the uses of the electron beam to penetrate hidden realms of nature.

While McKay’s main game had been lunar topsoil, he was branching into cosmic dust and put Thomas to work on that. He posed a question: How much carbon can be found in an interplanetary dust particle?

Thomas was fascinated with the study of these vanishingly small grains of dust that drift among the planets. She had spent a decade with them. The government regularly sent aircraft, usually spy planes, into the stratosphere with special devices that captured infalling particles before they burned up. Of the many tons of interplanetary dust that falls on Earth annually, most was thought to be the residue of comets and asteroids. As such, these particles would be remnants of the primordial solar system, kept orbiting in cold storage since the time before the first planets formed out of this same rubble.

Thomas developed a technique that used the electron beam, making it possible (she argued) to analyze, quantitatively, these incredibly tiny particles. But it was a tricky job, and she and McKay had a hard time selling the idea. People questioned whether anybody could measure such small entities. But Thomas pushed ahead, once again looking to “set the curve.”

The results were such a surprise that they only encouraged Thomas’s opposition. Until then, most people had supposed that cosmic dust particles were, by weight, maybe a couple percent carbon. But in some of the dust Thomas studied, the particles contained a whopping 30, perhaps even 40 percent carbon. This was more than twice the proportion found in the type of asteroids that, up to then, had been considered the most carbon-rich solid objects in the solar system. Space, it seemed, was
raining
a basic underpinning of life.

The unexpected findings upset people. “No way!” was the reaction she got. “You’re crazy!” She found her published work under assault.

Thomas began to feel disadvantaged by what she saw as her innate midwestern aversion to conflict, a thoughtful, slow-talking, “nice” approach to human interaction she had learned growing up. She had chosen a career in which she needed to be a black belt in the game of intellectual assertiveness. Once again, she was pushing herself. Somehow, she had to grow a thicker skin.

Her analysis held up, and over time the crowd began to tip toward wide acceptance of the new numbers. (Years later, in the spring of 2002, Thomas would attend a conference on interplanetary dust and be thrilled to hear colleagues quoting as conventional wisdom her old carbon numbers.)

Now—here was the rub—Thomas was just gaining this new foothold in her field, when McKay came along with his dubious Martian diversion. She was in no mood to go through another prizefight, so she decided that if she was going to associate herself with this madness, she would for darn sure make certain she and her collaborators were right.

She would run into another complication along the way. Because of the secrecy the project required, and her resulting failure to report how she was really spending her time, her employer (contractor Lockheed Martin) would end up giving her the lowest possible raise (about 0.5 percent) based on a yearly review, and this reflected poorly on her record. All would be forgiven when the truth emerged, but only after a year of this low regard. She came to feel the project justified such risks.

In the days and weeks after that initial meeting, Thomas started getting to know the rock. She took a look at it under a microscope. She took another. She read some papers on related topics that Romanek gave her. She began to see what had triggered the whispering, the excitement. The rock had her.

Thomas found the landscape of the rock entrancing—aesthetically, if nothing more. The magnified surfaces had a grayish tint to them, silvery almost, with hints of green. And they sparkled in the light. But the carbonate moons—they were spectacular! Looking at one of them under magnification was like staring into a headlight on a dark road. Here you were, touring this silvery-greenish-grayish textured landscape, and suddenly you encountered this bright, vibrant orange mass circled in black and white, as if drawn in ink by some Lilliputian cartoonist. The orangey moons were fairly circular, and had finely differentiated concentric rims: black, white in the middle, then black again, all the way around. It was extraordinary.

And, as McKay would later point out to her, there was another significant thing about them. The moons, or “headlights,” were not sitting on
top
of the silvery-gray rock. They were embedded
in
the rock. So some of the silvery-gray material had been worn away, or pitted, and then the carbonate globs had been deposited in the hole that was left.

She started out using the scanning electron microscope, just to get familiar with the target rock. With this instrument—David McKay’s primary instrument—she could make out surface patterns and textures, and she could see some little pebble-like objects scattered everywhere, especially in the black-and-white rims. Both the rims and the orange moons they encircled were complicated, not a solid lump of a single element but changing from one kind of mineral stew to another in concentric rings, almost like tree rings. The scenario of evolving natural conditions and events on Mars that would explain all this could not be simple either.

Thomas knew that Gibson and Romanek had concluded that the carbonates were deposited under relatively low temperature conditions, most likely by currents of fizzy, carbonated water that had flowed or percolated down through the rock as it lay beneath the Martian surface. Now Thomas was taking the investigation to a new scale and depth.

To carry out the crucial task of selecting and extracting the “best” carbonate globule, she would first spend several days looking down the eyepiece of an optical microscope, aided by generous rubs of Ben-Gay for neck tension. She would begin with several rock chips and search around until she found one on a fairly flat surface with enough underlying material so the tweezers could hold it. Extracting a chosen carbonate typically went like this: She placed the naked chip of rock underneath the microscope in a clean tray. She held it with one set of tweezers and then, using a second set of blunt-end tweezers, tapped around the outside of the carbonate moon, typically 300 microns across (about four times the diameter of a fine human hair and much too huge for her purposes). She tapped one edge, then another, working her way around the black-and-white Oreo rim. After she had tapped long enough—usually about two hours—she managed to pop the whole thing out of its setting. Then she crushed it and embedded the tiny pieces—no bigger than interplanetary dust particles, say 10 to 20 microns—into epoxy.

For this task, she avoided drinking coffee, and she usually scheduled key phases for a Sunday morning, when no one else was around and she wouldn’t have to worry about vibrations in Building 31.

Next she prepared the sample for deeper penetration by the big gun: the transmission electron microscope. It took about a week to get a sample ready.

She mounted the hard-won crumbs in a drop of epoxy atop a plastic “bullet.” After a bit of shaving and shaping, she inserted the bullet into a round holster that secured it and proceeded to cut off extremely thin sections of the sample—tissue-thin to the point of transparency—using a keen blade made of diamond.

She slid each thin section off into a “boat” of water and picked it up on a tiny copper grid that, to the unschooled eye, resembled a contact lens for a bumblebee. That little grid fit into a holder on the microscope, in the bull’s-eye of the electron beam.

The samples had to be transparent, thin enough for Thomas’s electron beam to pass through them. When explaining her approach to the uninitiated, she compared the rock samples to a loaf of bread. With the simpler scanning electron microscope, you would see the outer crust, its shape and surface textures. You could, for example, distinguish between Wonder bread and a baguette. But the view you got from the big transmission electron microscope was as if you removed a slice from the middle of the loaf: you could see the interior, assess the number of raisins or pecans; you could gauge the density of the mixture, expose the lurking weevil or the engagement ring that had fallen into the dough vat. That’s what this microscope gave you.

Thomas was essentially taking a three-dimensional object and transmitting its image onto a two-dimensional surface. That meant she had to know the orientation—the tilt—of her sample in order to interpret the flattened or foreshortened images.

When she was ready, she sat at the microscope, a device mounted on a countertop with a monitor attached to a tower, like a cathedral spire, that rose several feet above her head. She took the sliver of rock she had shaved off—some five hundred times smaller than the diameter of a human hair—and fired her electron beam down through the apparatus toward the target. The beam, acting like an X-ray of the structure, revealed internal features thousands of times smaller than the diameter of a fine human hair, right down to the regular patterns formed by the atoms in the crystals.