First Contact (15 page)

Mumma turned reflective about the challenge ahead. “In this kind of science, we can't really prove anything to be correct; we only can prove to be wrong. That's why we're always trying to confirm more. I learned pretty early on: Do not fall in love with your own interpretations and ideas. Be ready to accept a different view.” When you've followed a path like Mumma's, when you've pushed back all your life against the world as it is presented, it is impossible to be content with what you think you know.

•   •   •

Now that the search for Martian life is focused on both methane and the microscopic creatures that we know can live in extreme environments, researchers have fanned out across the globe to identify, analyze, and better understand similar habitats. Pan Conrad, an astrobiologist for NASA and a co-investigator for the agency's landmark Mars Science Laboratory mission, has taken a lead in this far-flung fieldwork. Since 2006, she has mapped in intensive detail small sections of extreme places like the Mojave Desert and Mono Lake in California, as well as the McMurdo Dry Valleys of Antarctica and the Svalbard archipelago in northern, arctic Norway. She takes the temperatures of rocks and minerals, she scans for signs of static electricity and magnetic fields, she details the chemical makeup of whatever spare, frigid, or blasted terrain she is focused on, and she takes samples that will allow her to know what lives there and what organic compounds can be found. Death Valley does not leap to mind as an obvious place to study the conditions that allow for life, but actually few are better. In this spot, the lowest not covered by water in the Western Hemisphere, we might as well have been on Mars—which is exactly the point.

I joined Conrad at Badwater in California's Death Valley before dawn because she wanted to do some before-and-after measurements on the salt-mineral scramble: before dawn, when the ground retains its nighttime conditions, and again when the baking sun was high. She had defined a small area of jumble off a salt-slicked path and was into her third round of measurements when her voice rose in excitement: The static electricity meter was delivering a surprise. Laid on the crusty salt, the pocket-size meter was hardly moving. But when placed on the dun-colored toppings—mostly sulfur-based minerals—it shot up. She repeated the measurements several dozen times and found the same pattern repeated every time. “That,” she said, “is just so cool. I have no idea what it means, but it's telling a story and I want to know it.” We would return to the spot twice more that day, once in the afternoon heat and once in the dark of night.

Conrad is an expert, a pioneer really, in studying these extreme minihabitats. She's a mineralogist by training, though she's also performed as
a professional opera singer and was moviemaker James Cameron's companion for a trip to the Pacific floor in a Russian submersible. She began measuring and probing these miniature worlds after being selected in 2004 as one of several dozen investigators for a collection of instruments on NASA's next big mission to Mars, the Mars Science Laboratory. Three times larger than any previous Mars rover, the MSL is designed to travel as far as twelve miles from its landing site on its official quest to determine whether that small piece of Mars turf, selected with painstaking care, is or was ever habitable. That's a step short of the 1976 Viking goal of actually searching for Martian life, but because of the controversy and confusion over the Viking results NASA has never again flown a “life detection” mission to Mars. The agency still doesn't consider the time to be right, but the Mars Laboratory—scheduled to launch in late 2011 and arrive on Mars the next year—is a significant step in that direction.

The collection of instruments that Conrad and her colleagues are in charge of is called SAM, Sample Analysis at Mars. SAM's job is in many ways the most ambitious on the rover: to search for organic material, the kind of carbon-based compounds needed for life as we know it. Conrad's approach is based on this logic: MSL will be sending back the most detailed information ever about the chemical makeup of the rocks, minerals, and atmosphere of one promising destination on Mars, and if all goes well it will do that for several years. Because the location is certain to be extreme, like all of Mars as it's currently known, her team needs to know as much as possible about extreme environments on Earth so members can better understand the information that MSL will be sending back. She doesn't know what will or won't be helpful, but she wants to have an encyclopedia of extreme conditions data at her fingertips in case it becomes suddenly relevant. NASA's Mars mantra has long been “follow the water” as the surest path to habitable places and possibly life; Conrad's goal is to add other guideposts based on the presence, structure, and behavior of particular molecules, compounds, and minerals.

As she explained it, the actual job of looking for current or past extraterrestrial
life is not what people imagine. Typically, extraterrestrials are envisioned as strange but visible, touchable creatures or vaguely human-looking aliens. But what Conrad, the MSL team, and future missions will be looking for is the presence, or former presence, of a life too small to see without a microscope—the kinds of microbes found in those South African mines or under Antarctic glaciers. As a result, they have to look at how that microbe may have changed the site's organics, minerals, and rocks, at the possible gases created by the current or past presence of a living bacteria-like creature, or at the chemical and electromagnetic landscape to see if it could conceivably support life. Physics, astronomy, meteorology, organic chemistry, spectrometry, the relatively new field of geomicrobiology—they all provide important tools in the forensics of extraterrestrial life. A lot of work for a seemingly limited return, but do remember what's at stake. There is a general scientific consensus that if life of any sort is found on another body in our solar system, and if that life has a detectably different origin than life on Earth, then all the calculations about life in the cosmos change dramatically. One genesis in a solar system and it could be a fluke. Two geneses and suddenly life becomes more of a feature than an anomaly; a cosmic commonplace. And if life is common elsewhere, then there's every reason to believe it has undergone evolution as on Earth, and could have become complex or even intelligent. One small microbe for Mars, one giant leap for life in the cosmos.

Intrigued by the different charges found in the brown crusts and the white carbonate “fluffies” all around them, Conrad decided to return later in evening with one of her big guns, a portable Raman spectrometer. A sophisticated (and, at twenty-three thousand dollars, expensive) piece of equipment, it can tell researchers in the field what molecules make up a particular rock or sediment or mineral they encounter. Used in mining and chemistry of all kinds, the Raman laser spectrometer (named after the man who theorized how it might work, C. V. Raman) has been adopted by astrobiology as an indispensable tool for analyzing other planets and celestial bodies, as well as their Earthly analogues. The portable spectrometer,
called a “Rockhound,” looks rather like a clunky but powerful ray gun, with a point-and-shoot laser beam that can harm the eyes or burn the skin. But the instrument loses its Star Wars menace when it's tethered to the Toughbook laptop computer it needs to perform.

Conrad wanted to come back at night because the Raman spectrometer works much better without light interference, and during the day Badwater was nothing but that. The moon was rising over the Amargosa Range on the eastern side of the valley just as the sun had begun to light the sky when we first arrived at the site sixteen hours before. We walked a ways on the salt pathway and, using her miner's light to scan the landscape, Conrad found another spot to analyze, this time pursuing “extreme science.”

To help explain the differences in electrical charge, Conrad needed to know exactly what minerals and elements made up the white and brown deposits. She had already taken samples to analyze in her lab—which for twelve years was at NASA's Jet Propulsion Laboratory, but would soon be at the agency's Goddard Space Flight Center—but doing work in the field is part of her self-imposed training for the Mars mission. So she proceeded as if Death Valley were Mars, and set out to learn then and there what was putting out those very different electric charges and why.

Space missions are famous for their glitches, and we had one with the Toughbook and spectrometer. For more than an hour the computer refused to read what the Raman was picking up, and there were any number of reasons why. The instruments had been exposed to great heat in the car trunk, they were now being buffeted by wind in what amounted to an enormous salt bowl, and the temperatures were substantially below what they had been several hours before. Nothing so dramatic as conditions on Mars, but an extreme changeability nonetheless. The moon was fully overhead when finally the first squiggly lines of a spectral pattern showed up. Each peak on the graph is the signature spectral pattern of a vibrating bond between atoms in a mineral or compound; collected, the peaks reveal the identity of the ray-gunned materials. The graphs for the white valleys were, not surprisingly, very different from the brownish peaks. It was quite
a sight. Conrad, seated on a tarp in a failed effort to get comfortable on the hard jumble below, the glow of the Toughbook, and another member of the team carefully moving the spectrometer ray gun from white to brown and back to white again. The moonglow kept away complete darkness, but it was well into the night and we were out on the Badwater salt with no other humans for miles around. It was noiseless, except for the wind. Mars in the day; Mars at night.

Death Valley is a popular site for Mars analogue research, but it's nothing compared to Svalbard, a region on the northern tip of Norway, well into the Arctic Circle. When the men and women who run Martian or lunar or other planetary experiments want to try out their equipment and learn the challenges, they now regularly go to Svalbard, an archipelago of islands best known for the town of Spitsbergen, their harsh beauty, and their three-thousand-plus polar bears. These animals are sufficiently fierce that when researchers (or any locals) go out of the towns, they are required to take a shotgun. It's a place that's often fogged in, where instruments can quickly die outside if not kept properly warm, where romances tend to flourish and breakdowns are not unheard-of, and where astrobiologists can do great research and can test their Mars or lunar rovers and other experimental equipment. And in the arctic summer, when the expeditions occur, it's light twenty-four hours a day.

The expeditions remain under the leadership of a Norwegian geologist named Hans Erik Amundsen, who did his doctoral research in Svalbard starting in 1997 and organized the first, almost impromptu international mission in 2003. The site has become valuable not only for testing instruments and training people on how to use them in Mars-like conditions, but also as a kind of scientific Outward Bound. “Nobody's allowed to work alone, and nobody goes ashore unless they've been trained on what to do if you encounter a polar bear. Everyone is in a group of maybe four to seven people with radio communication to the boat. Everyone has to be accounted for all the time, and at least one team member has a rifle and flare guns in case they come across a bear,” says Amundsen. Many on the
expeditions are high-powered scientists and engineers, and they often work by themselves and control their days. “They're alpha personalities, but all that has to be put aside and they have to meld into a team,” is how Amundsen puts it.

The 2008 and 2009 expeditions focused on testing instruments for the Mars Science Laboratory scheduled to launch in 2011 and land on Mars in 2012. Although its mission is to determine “habitability” on Mars, scientists on the MSL team are convinced that the rover, the size of a Mini Cooper and weighing in at almost one ton, actually could detect life under certain circumstances. They say it, however, in something of a whisper. That's because the rover and all its instruments would have to be sterilized to a higher and far more expensive level if MSL were officially deemed a “life detection” mission. So being slightly less than that has its advantages.

Svalbard is a great test range for cutting-edge ideas, as well as new equipment. Mars scientists disagree about many things, but one that unifies most of them is the long-term goal of a “sample return” mission: sending a spaceship to Mars, collecting some especially promising rocks and minerals, and bringing them uncontaminated back to Earth via another spaceship. The challenges are enormous, but the United States does have an impressive track record on Mars—it's the only nation to ever land a spacecraft safely on the planet; the Russians tried many times unsuccessfully, as did the British with their Beagle spacecraft. But now, NASA and ESA have not only joined up for the ExoMars missions to measure trace gases like methane and then to land rovers on the planet in 2016 and 2018; they've also begun brainstorming and testing out ways to collect rock samples on Mars and bring them back to Earth. Svalbard has become a test site again for prototypes of the rover that will collect and then safely store the samples, called the Mars Astrobiology Explorer-Cacher, or MAX-C.

But the immediate project on everyone's mind is MSL, and the man in the spotlight for that is Paul Mahaffy, a two-time Svalbard expedition member and the principal investigator for the Sample Analysis at Mars, the many-faceted instrument on MSL designed to detect organic material
and possibly life. A somewhat rumpled, low-key physical chemist, he will oversee a team of several dozen people who will conduct the most extensive and most significant investigation ever on the Martian surface for the kinds of organic, carbon-based materials that could lead to or be associated with life. Other instruments on MSL will definitively determine if minerals present were formed, as expected, in the presence of water, while another will shoot out an intense laser beam that will vaporize a small amount of nearby rock, allowing a spectrometer to then read much better what the rock is made of. Another instrument will be able to sniff for methane, which after Mumma's discovery has become a high priority. The reach of all these instruments will be greatly expanded by the ability of MSL to travel at least twelve miles during its two-year tour of Martian duty.