The Rock From Mars (40 page)

In characteristic fashion, as he had done for the Mars Meteorite Group, Gibson ordered polo shirts for fellow team members, at his expense, with the legend “Beagle 2 Mars, the search for life.” It was important, he believed, for the people in the trenches, the unsung technicians, to feel connected to the mission, and the shirts were his way of doing that. Gibson also outfitted his Lexus SUV in Houston with a special license plate frame that read: “Beagle 2 Mars” on top and “Search 4 Life” on the bottom.

Unfortunately, on Christmas Day 2003, at Beagle’s landing time, engineers listened in vain for the Beagle call sign—a nine-note composition written for the mission by the rock group Blur. The Martian devils had snared another Earth craft. Despite repeated attempts and the assistance of other spacecraft operating at Mars, they never heard from it again.

Gibson felt a special agony when, weeks later, in March 2004, instruments on Earth and aboard the European Express orbiter at Mars indeed detected signs of methane in the Martian atmosphere. One explanation was Martians. But there were good reasons to suspect there are other ways of producing methane, such as hidden modern-day volcanic activity, for example, or mineral chemistry. Oh, he thought, what the Beagle instruments might have done with that methane data. He held out hope that NASA might be persuaded to incorporate Pillinger’s backup instruments (still sitting in the London workshop) into a future mission, to help answer the big questions about life on Mars.

Now, as Gibson worked on his Antarctica project, the nail on the middle finger of his right hand still bore a small, fading black mark where he had accidentally struck his hand on a water spigot in the London apartment he’d rented for what he’d hoped would be months of Beagle 2 operations. It was a very minor battle scar, but a sad reminder of what might have been.

Andrew Steele moved his wife and daughter, now six, from England and into a home in the suburbs of Washington, D.C. (Soon they would be expecting a second child.) As the high-pitched white noise of the emerging seventeen-year cicada horde rose in the old trees outside his lab at the Carnegie Institution, he was busy juggling work there with the occasional field trip and with “big-picture” jobs he had taken on. As chairman of one of the committees appointed to advise NASA on the next round of Mars exploration missions, he was rushing to finish a report.

The previous year, in August 2003, the riddles in the rock had prompted Steele to join an annual international field expedition to the archipelago of Svalbard, in the Arctic Ocean between Norway and the North Pole. It was another frigid desert, where glaciers lay like sheet cakes and stretched like fingers toward the Bock fjord. Here, in hot springs, the heated water climbed up through some twelve hundred feet (about four hundred meters) of permafrost.

Several types of Mars-like environments conveniently combined in this one place. There was rocky rubble—breccia—similar to what Spirit was seeing in Mars’s Gusev Crater. There were sites with evaporates and concretions like the “blueberries” Opportunity was finding. And there were evocative “red beds”—elevations where reddish floodplain sediments were crosscut by gullies. They seemed so eerily similar to the startling gulley-wash formations detected on Mars by the orbiting Global Surveyor that Steele found they raised the hairs on his neck.

Here, on the island of Spitsbergen, sat a volcano named Sverrefjell, after an old Norwegian king. This volcanic system, raked over by glaciers, was the only known spot on Earth that manufactured carbonate globules very similar to those found in the Allan Hills rock—same composition, same concentric layering, same Oreo-cookie rims.

As Steele’s Svalbard team leader enthused, “That poor little Mars rock traveled millions of miles,” and it was just one rock, with no context. “Here, we have the ‘crime scene’ intact. We can go to these volcanic centers and look at mineral deposits identical to those you know exist on Mars and you can look at the whole scenario and try to figure out what on Earth was going on—and was, or was not, biology involved.”

Carbonates are not usually found in volcanoes, but in this case the lava pipes that come from deep in the Earth apparently carried them up through the permafrost. The lava had spewed out, the pipes were left empty, and the empty tubes gradually filled with the hardened rubble. At some point, they apparently also filled with water.

When the lava cooled some million or so years ago, it released gases, which left vesicles, or pores, in the rock. The carbonate globules had been captured in these pores.

The carbonates appeared to have been deposited by water reacting with the basalt at low temperatures—in a moderate hot spring like the setting in which the Martian carbonates (in the McKay team’s analysis) had most likely been deposited.

The large international team that included Steele was trying to decipher in detail these processes by which the complex carbonate rosettes had been created, at least for the terrestrial case. At the same time, they were field-testing strategies and tools for life detection, some of which would win berths on upcoming Mars missions.

When Steele and company examined the carbonate globules (taken from the cavities in the interior of the rock to avoid “analyzing bird shit”), it turned out they were full of organic material. The researchers were shocked. You were not supposed to find organic material inside volcanic flows. The researchers were not even sure yet what was the right question to ask in order to figure out if this betokened biology—or not.

Most terrestrial rocks contain microscopic life; the samples from the volcanoes were no exception. The striking thing was that life seemed to be closely and intimately associated with carbonate globules taken from inside the rock. When the researchers stained a sample of carbonate with a substance that binds to DNA, they saw microbes crawling all over it. In some samples, there was also biofilm, a snotty residue left by microorganisms, coating the walls of the cavities and of the carbonate globules themselves, and there were hydrocarbons “of unknown origins.”

Here you had a rock very much like the rock from Mars, and you could see organic processes going on in that rock.

Back in civilization, one of the hard truths that Steele and many more-experienced Mars-exploration planners had been confronting, through all the surveys and meetings and teleconferences, was the degree to which they still lacked the tools for distinguishing life at its most ancient and primitive from mere chemistry, and Martian signs from terrestrial. There was still no consensus even about the basic definition of life.

“It’s assumed we’ll look,” Steele said. “We have no idea what to look for, how to look for it, where to go to really look for it, or what to look with.”

The important thing was that people were finally taking steps to address the abundant deficiencies. Steele, like many others, traced this promising turn directly to the rock from Allan Hills and the work of the McKay group.

Life on Earth represented a sample of only one. There should be organic chemistry happening on Mars, Steele thought. Life had formed or it had not. As Sagan had said, to learn of either outcome would be remarkable, and unimaginably fascinating.

McKay volunteered as a spear catcher in yet another controversy—one that returned him to nanobacteria issues, this time with a medical angle. The research focused on mysterious “autonomously self-replicating particles,” spheres armored with a hard calcium phosphate coat, first detected in the early 1990s by Finnish researchers in fluids such as cow serum that were routinely used in labs to grow cells. In 1998, another published paper linked the spherical nanothings with diseases of calcification, such as kidney stones and hardening of the arteries—prompting interest from the Mayo Clinic and the National Institutes of Health, as well as profit-seeking commercial entrepreneurs.

In fact, the lead researcher on the Finnish studies credited the controversy connected with the McKay group’s claims with his ability to get his work published. Previously, reviewers had simply rejected it.

Even though he had to scrounge to find the money to pay her, McKay brought one of the lead authors of the 1998 paper, Neva Ciftcioglu, to work in his lab. There was heated disagreement about whether these nanoentities, or nanobes, were actually living organisms—or something for which no proper nomenclature yet existed. You could grow them in the lab. And at 200 nanometers or smaller, they could pass through the filters intended to sterilize medicines used for vaccinations, getting into places where they were decidedly unwanted. But nobody had found genetic material in them. Though some people were convinced they were living bacteria, they could also be something else—some stage—between bacteria and viruses.

Ciftcioglu was hunting for evidence of even the smallest scrap of DNA in the mystery particles. Some people, McKay included, thought the research might lead to beneficial medical treatment in any number of diseases, including some ailments that afflicted astronauts in weightlessness.

But McKay, not surprisingly, had another reason for bringing Ciftcioglu to Houston. Her putative nanobes were roughly the same size as the fossil-like shapes he and his team had seen in the Martian meteorite—the ones deemed too small to contain the machinery of life.

In 1998, in response to a NASA request and in an effort to deal with the issues raised in the nanofossil skirmishes, the National Academy of Sciences had gathered a blue-ribbon panel of experts to try to define the minimum size for life. After months of discussion, they had agreed on a bottom line: the volume in a sphere 200 nanometers across.

At about that time, McKay was giving ground, conceding that entities smaller than 100-nanometer spheres were not “indicative of bacteria” after all. However, he said, the original fossil-like structures might be bits and pieces of defunct Martian microbes.

Some experts saw both sides yielding toward a new middle ground on the question of strangely small biological entities, thanks in part to work like that of Ciftcioglu’s Finnish colleagues, and also to a new report of 50-nanometer nanobes in Australian rocks.

If McKay’s revisionist argument sounded “like top-of-the-head improvising by one stuck in a tight corner,” wrote science historian Steven Dick and biologist James Strick in
The Living Universe: NASA and the Development of Astrobiology,
“we must also note that, by the time the [academy] report on nanobacteria appeared at the end of 1999, their own 200 nanometer published figure was also being finessed to leave some ‘wiggle room.’ ” The National Academy of Sciences experts adjusted their position to allow for the possibility of primitive unknown microbes as small as 50 nanometers. In a statement that must have pleased McKay, one panel member, John Baross, told
The
New York Times,
“We have to think about them [nanobes] in a different way, and one is that they are components that function as a living organism only in totality, the whole being greater than the sum of the parts.”

Down the rabbit hole, at unprecedented magnification, life took on all sorts of unexpected possibilities.

The mother of planetary rocks, somewhat diminished, sat serenely in its nitrogen vault on the second floor of the Building 31 annex. A sizable chunk of it was on display in the Smithsonian in Washington. Chips and shards of it resided in more than sixty laboratories around the world. More than one hundred metric tons of equipment, the most advanced technology the planet could muster, had been brought to bear on it.

People had published at least eighteen peer-reviewed papers in support of the McKay group’s claims; some twenty-nine papers opposed those claims. Numerous others were hard to place cleanly on one side of the line or another, and still others studied the rock but were not particularly relevant to the debate about ancient Martian life. In any case, as Allan Treiman, one of the more prominent gadflies and critics of the McKay claims, noted, “A body count does not prove who won the war.” The debate would continue and expand—on Mars.

The rock was a catalyst. It fell into a volatile brew of human endeavors and yearnings. It changed the recipe, and became part of the new brew. It changed people’s lives and it changed their thinking.

Thanks in part to the rock, with its clear evidence of organics on early Mars, the American space program was revamping its Mars campaign and mainstreaming the search for extraterrestrial life there. Spurred by the rock and Dan Goldin, NASA had turned itself into a “biology-centric” agency, organized around the cosmic search for life’s origins.

The controversy over the rock had driven forward key areas of astrobiology. And with the rock’s riddles in mind, biologists of various stripes were tackling the history of life on Earth with fresh eyes and techniques.

The hostilities unleashed on Terrible Tuesday 1996 had:

•                  Helped expand the fields of geology, biology, and planetary sciences into the nanometer realm.

•                  Alerted Mars mission planners to how shockingly difficult it would be to assess the meaning of any bits of rock or dust brought back from Mars, triggering efforts to find solutions and to use Mars-like settings on Earth as rehearsal stages.

•                  Helped narrow the selection of future landing sites on Mars.

•                  Increased awareness of the potential for interplanetary contamination, and the danger that Earth explorers could upset unsuspected ecosystems on other worlds as well as the reverse possibility of a biological threat to Earthlings.

•                  Dramatized complexities involved in the struggle to understand how chemistry turns to biology (on any planet).

•                  Accelerated the useful cross-bedding of scientific disciplines (along with a proliferation of multisyllabic skills descriptions: cosmogeophysicist, geoastrophysicist, paleomicrobiocosmogeochemist).

•                  Enhanced understanding of Martian meteorites, provoking research that would aid in sorting out organic Earth contaminants from authentic alien material.

•                  Demonstrated lively public interest and funding support for the search for extraterrestrial life and related work.