The Quest for Mars: NASA scientists and Their Search for Life Beyond Earth

The question got me thinking about the famous Miller-Urey experiment designed to illuminate the origins of life. In 1953, two scientists at the University of Chicago, Stanley L. Miller and Harold Urey, put gaseous methane, ammonia, water vapor, and liquid water – ingredients thought to simulate a primitive Earth atmosphere – into a closed system, and sent an electrical discharge spark through the mixture. The gases interacted, and a gummy residue formed; analysis showed it contained organic molecules, including many amino acids, which are the building blocks of life. It had been previously thought that the prerequisites for life were rather special and demanding and occurred only on Earth, but the experiment suggested that all you needed to produce life were a few simple, readily available chemicals and an energy source. These things could be found on other planets, on some asteroids, and most probably on Mars. You don’t need oxygen for life to develop, and you don’t even need the Sun; the heat source could be volcanic or subterranean. I asked Jim, “If you put together all the necessary ingredients, does life inevitably develop?” Because if it did, it could be developing on Mars and throughout the universe, wherever those things are found.

“Larry,” he said, “you’ve just asked the Genesis Question. We don’t know the answer. Some people believe it could, some believe it couldn’t. A few billion years ago in the history of this planet, and in the history of Mars, and possibly in the history of other places, there may have been very sporadic conditions that might have been able to sustain life. But that was at the time when the planets were being constantly bombarded by junk leftover from when the Solar System formed. There was a lot of leftover crap, and it eventually smashed into the planets. We think all the planets formed about four point seven billion years ago in a relatively commonplace little spinning nebula of dust that collapsed to produce them and also spun off stuff that didn’t quite make it, like the materials in the asteroid belt that occasionally crash into us.” And then he said: “There was even an idea that life sprang forth on those objects, and there was a great so-called ‘panspermia’ wherein life spread from one place to another from some unknown source. Not us. We weren’t the source, according to panspermia theory. We were just one of the places where it landed and survived.”

I casually remarked that panspermia sounded like the answer to the question of life in the universe.

“Be careful,” Jim said. “The idea is very controversial, and often misunderstood. A lot depends on whom you talk to.” Although there is no consensus about life on Mars now, he told me, many scientists have come to believe that it’s very hard to imagine that Mars didn’t have a failed attempt at life forms at some point in its history. “The question is: where did it go? Seeing the existence of life on Mars would be like finding the Rosetta Stone. We may be alone now, but not in the past.” Jim thinks of Mars as the mother of all control experiments. “The theory goes like this: the Earth is a very messy, complicated, intersecting set of systems, but we also need a sandbox to play in, and the best sandbox we have is Mars. It’s a natural control experiment for things we want to understand about our own planet, if we were able to strip away and isolate some of the variables. For instance, Mars is colder and drier. Water exists there as ice or as a gas in the atmosphere. When it did exist as a liquid, it probably did so only briefly. There is no biosphere altering the planet, as we have on Earth. If it ever started, it failed.”

It’s possible that we could end up like Mars, as the Sun fades. Jim tells me that if all the water on Earth froze and then evaporated, we could very well have conditions that would suck the oxygen out of our atmosphere without renewing it.

I begin to think of Mars as Earth reduced to the essentials. For purposes of scientific research, it’s more promising than the moon, even though it is much harder to reach. “Back in the days of Apollo, we could use military-class technology to zip up to the moon and fly around and be very clever because we had unlimited funds and a national commitment from our president to put human beings there. We don’t have that commitment for Mars,” Jim reminds me, making the idea of regular transits to Mars suddenly sound sensible. “People argue that NASA will never have carte blanche like that again. Nowadays, you have to keep the price way down. It means that when you go to Mars you can’t carry enough fuel to go into the orbit you want. You have to use the gravity and atmosphere of Mars itself to get you there.”

Jim takes heart from historical precedents for these difficulties. “Think of them in terms of the exploration of our own planet,” he says. “Think of the early sailors willing to risk their lives sailing from Greece to Crete, an island about a day away, if the wind blows right. They might be willing to do that because, what the heck? That’s analogous to going to the moon, which we can reach in a matter of a few days. Now imagine sailing not from Greece to Crete but from Greece to North America. That’s the scale of difference we’re talking about when we send spacecraft out to Mars.” At that scale, the celestial sailors will have to learn to improvise in order to survive, just their maritime forebears did.

While we linger at the seep, Jim reminds me that only thirty-five years ago, there was nothing here but the Atlantic Ocean and fresh air. And now we are standing on rock containing copious evidence of bacteria. Could life have spread as quickly on a Martian volcano? Well, why not? No one knows. Questions like these form the basis for “astrobiology,” the search for extraterrestrial life – generally in the form of primitive bacteria invisible to the naked eye. Although the questions posed by astrobiology – or, as it is sometimes called, exobiology – have concerned NASA scientists for over twenty years, the field has suddenly entered a period of rapid expansion, as it moves from the realm of the purely speculative to the potentially demonstrable.

Biologists are coming around to the idea that Earth, while complex and idiosyncratic, is hardly unique. Our planet does not necessarily contain a divine, magical, or fluke recipe for life. On the contrary, life emerged here when our planet was less than a billion years old, as the outcome of geologic and chemical processes. It might have been the inevitable outcome; if so, it could easily appear throughout the Solar System and the universe.

In that case, why has extraterrestrial life been so hard to find? One thing is now clear to many scientists. As the song goes, they’ve been looking for life in all the wrong places – mainly in moderate, sunlit, moist environments. As biologists develop a greater understanding of all the unlikely, remote places where life exists on Earth, it has become apparent that there is much greater latitude. Life forms can be so hardy and unpredictable that they will find a way to exist just about anywhere. And at the microbial level, life can be so simple it seems barely alive at all. Still, to qualify as life, the stuff has to satisfy at least two widely accepted conditions. It must be able to replicate, and it must be able to mutate and evolve. Darwin’s principles of natural selection apply at all levels of life, and if life is discovered on Mars, or anywhere else in the universe, natural selection will apply there, as well.

We make our way along shallow erosional gullies, which provide a foothold on the volcano’s sheer upper reaches, until we arrive at the summit of Surtsey, a precarious location high above the surface of the North Atlantic. Jim, who’s lighter and more agile, is a lot better adapted to climbing than I. The jet lag and lack of sleep are taking their toll; my heart thumps wildly, and the wind pushes me off balance. I look up, trying to orient myself. Heimaey, so solid and inviting by comparison, floats in the distance, and beyond, Iceland itself. After a brief rest, we head down the steep slope.

By mid-afternoon, we reach a small research hut at the base of the volcano, where the Icelandic botanists who flew in with us have gathered. A pot of water comes to a boil on a little propane stove, a welcome sight, a bit of Earth on Mars. Over a mug of instant coffee, I converse with a botanist, Sturla Fridricksson, who, Jim explains, is considered the grand old man of Surtsey research. Sturla’s face has been seamed and cured to a leathery perfection by the Northern sun. He looks as though he’s served time on the Kon-Tiki. Just as he launches into a complete geological history of Surtsey, a saga in itself, the Icelandic Coast Guard returns to rescue us. Their helicopter touches down with a great throbbing racket; the rotors feel like they’re sucking the air right out of my nostrils. Silent and overwhelmed with impressions from our day’s exploration, Jim and I begin the journey back to the mainland, as though returning to Earth.

When he’s not climbing active volcanoes, Jim Garvin often roams the hallways at his place of work, NASA’s Goddard Space Flight Center in Greenbelt, Maryland. That was where we met, exactly one year earlier, when I was visiting a friend who also works there. Jim was standing in a busy corridor, holding forth on the subject of Mars, and within minutes, the sound of his voice attracted a crowd of curious scientists, who drifted away from whatever they were doing to listen. Somebody ought to be getting this down, I thought, and started to take notes as fast as I could. When we began to talk, he identified himself as a co-investigator for the Mars Global Surveyor (MGS), a state-of-the-art spacecraft designed to orbit Mars and conduct a number of pioneering experiments, including mapping the surface of the Red Planet in more detail than is available for Earth.

His special area of interest, he explained, is an instrument on MGS known as a laser altimeter – a laser designed to fire impulses at the surface of Mars. Minute fluctuations in the time it takes for the impulses to return create a three-dimensional picture of the surface, accurate to within a few meters. This is an incredibly intricate engineering feat – akin to extending a tape measure all the way from New York City to Washington, D.C., to determine the surface variations on the dome of the Capitol, while recording the results in a moving car back in New York.

At that first encounter, Jim invited me – as he does everyone he meets – to share his obsession with Mars. He is a rigorous scientist, but underneath the rigor lurks a romantic explorer. Mars is not just a planet to him; it holds, potentially, the answers to the riddles of the universe. At the time of this meeting, in July 1997, the Pathfinder spacecraft had just landed on the Red Planet, and its tiny rover, Sojourner Truth, had captured the imagination of the scientific community and people around the world, who were able to follow the extraterrestrial proceedings closely on the Internet. As I talked with Jim about the development of Mars exploration, it occurred to me that Pathfinder belonged to a much larger story – mankind’s exploration of Mars – and that the exploration was itself part of an even larger story: the search for the origins of life on Earth and throughout the universe.

Despite the sophistication of the new missions to Mars, Jim waxes nostalgic about the Viking program of the mid-70s – “the Cadillac of missions,” he says. “They actually had better equipment then.” Of course, it cost the American taxpayer about ten times as much as the current hardware does. He became involved with the Viking missions when he was still an undergraduate at Brown; a geology major, he helped to analyze images from the Viking 2 lander spacecraft, and he got hooked on the study of Mars. (Planetary spacecraft come in three basic varieties – flybys, landers, and orbiters. The flybys whiz past a planet on their way to somewhere else. An orbiter circles a planet. And a lander touches down on the surface.)

Just when he thought he’d found his vocation, the Viking missions ended, and NASA closed the book on Mars exploration. The missions, Jim often says, were the victims of their own success. They sent back thousands of stunning color images, and provided enough data to keep scientists occupied for two decades. They accomplished so much it seemed there was nothing left to do except send people to Mars, and there wasn’t enough money in the budget for that.

After graduation, Jim went to Stanford for an advanced degree in computer science. The life of a geek was not his style. So what if he could de-bug his colleagues’ programs and make them run faster? The work was too routine, too solitary, too stationary. He returned to Brown for his Ph.D. in geology, where he studied under Tim Mutch and Jim Head, who also taught a popular undergraduate course known as “Rocks for Jocks.” One day, Mutch said to Head, “You know, there are no fundamental problems left on Earth.” Mutch turned his attention to the planets and published an important – one is tempted to call it groundbreaking – book, The Geology of Mars, in 1976. This was a revolutionary idea, to study the geology of the Red Planet in a scientific manner. Geology claimed a gigantic new turf: the Solar System, and, by extension, planets and asteroids everywhere. All at once, geology became an integral part of the exploration of space, and Mutch was leading the way, training a new generation of planetary geologists, including Jim Garvin.

“At first glance,” Jim says, “Tim Mutch might have been perceived as a Jimmy Stewart type of character: tall, thin, amiable, and always above-board, almost self-deprecating. Deeper inside the man was his passion and resolve.” Occasionally, he’d remark to Jim, in an offhand way, “You’re a Mars person. Did you know that?” And at a party, he buttonholed his fast-talking young graduate student and said, “Jim, you and a few others are the future of Mars exploration, so it is yours to make it happen.” That was, he says, “heavy stuff” for a twenty-one-year-old grad student to hear.

As it happened, Brown played a role in analyzing data from the two Viking landers, so Jim had access to the latest developments in Mars research and analysis. He still revels in the memory as if it were his first love. It was his first love. In defiance of conventional geological practice, Mutch concentrated on the enigmatic landforms of Mars. “This was revolutionary thinking to me, as most geologists argue that studying typical landforms is the best way to learn how a surface was formed,” Jim says. “But Tim argued that finding those enigmatic landscapes might be more pivotal in the workings of Mars than background normal landscapes.”

In 1980, Tim Mutch led an expedition to the Himalayas. He made a successful ascent accompanied by two graduate students, but the weather turned foul during their descent. One of his crampons broke, and it was impossible for him to continue. The students wanted to carry him down, but he told them, “No way. Strap me in here. Go back to base camp and get help and come back for me.” By then, he might have been delirious from lack of oxygen. The students went down to base camp, and he probably thought they’d return in an hour to rescue him, but they had a rough time getting through the storm, and by the time they made it back, eight hours had passed, and there was no sign of Tim. His body was never found. The best guess is that the storm blew him off the mountain.

About a year later, Tim’s widow, Madeline, held a memorial gathering to which Jim was invited. She showed slides taken during her husband’s fatal descent. It was unbearably moving, especially for Jim, who had been Tim Mutch’s last graduate student. In an obscure but deeply felt way, Jim believed that as Mutch’s disciple, he was supposed to carry the torch – but where? He didn’t know, and even today, he still doesn’t know where, exactly, but he always hears Mutch’s voice in his ear, pointing the way to the Red Planet. And NASA was the only way to get there.

During Jim’s early career at the agency, an unofficial Mars Underground developed within NASA’s bureaucracy. This was a loosely-knit affiliation of scientists and engineers who maintained a keen interest in Mars, despite the agency’s lack of Mars programs, and who also maintained a fervent desire to return to the Red Planet, first with robotic spacecraft, and later, with people, if the money and the motivation could somehow be found. The Mars Underground published papers, held symposia, and tended the flame through difficult times.

These were not easy years for Jim. An instrument he’d proposed, a radar altimeter, was initially selected for a Mars mission, but later deselected, or dropped. Soon after, in January 1986, the Space Shuttle Challenger disaster threw the agency into crisis. A period of soul-searching ensued within NASA. He worked for Sally Ride, the astronaut, on a project designed to renew the agency. Out of copious discussions, the Ride committee produced a grand new vision for NASA: the United States must return to the moon, and, beyond that, establish a permanent lunar base. Their recommendations were never acted on. After the group disbanded, Jim’s laser altimeter was selected for the Mars Observer mission, which ended in catastrophe in September 1993.

Finally, in 1996, Mars’s time came round again. First, there was NASA’s announcement of the discovery of nano-fossils in a meteorite from Mars. Suddenly, as one scientist put it, NASA was bitten by the life-on-Mars bug. The discovery, by a team of NASA scientists, gave the agency a focus it had been lacking since the Challenger disaster a decade earlier. The following year, the Pathfinder spacecraft settled on Mars on the Fourth of July, and its miniature rover rolled down a ramp and inched across the surface of the Red Planet, acting as a robotic geologist. “We can now get to the Red Planet for the price of a big-budget Hollywood movie,” NASA claimed. Jim puts it even more simply: “Mars is back.” It’s his mantra.

The Keflavik Naval Air Station, where Jim and I are billeted in Iceland, is a sprawling NATO base that once served as an essential Cold War outpost. These days, it’s mostly a stopover for young European pilots who bring their planes in from France or Italy; they drink a lot, sleep a little, and depart at first light. Although Jim is a civil servant, his quasi-military status becomes evident the moment he enters the base. He salutes everybody, and they salute back – at least, some do. “My civil service status grade is equivalent to a Colonel’s,” he says, “but no one here is aware of that.”

We’re assigned to the Bachelor Officers Quarters, cement barracks strongly reminiscent of college dormitories. The penetrating odor of burned pizza crust wafts through the halls; the walls reverberate with blasts of heavy metal music. Occasionally, you hear squeals and shouts from girls who may or may not belong here. When you look out the window, you see a landscape so flat and featureless it could be Nebraska. There are schools, playgrounds, pickup trucks, a movie theater, a bowling alley, and a Wendy’s where they play “God Bless America,” country-style, over the PA system. The unofficial motto of the base might be: “Keflavik, a Nice Place to Raise a Family.”

In July, it’s light all the time, and the only way you can tell it’s late in Keflavik is that it gets very quiet. For a few hours, there are no cars zipping around the roads, no fighter jets streaking overhead. Around midnight, there’s a sort of dusk, a suggestion of darkness like a shadow across the sky, but it soon passes, and brightness returns by 2 AM or so.

A few days after our Surtsey expedition, Jim goes forth in search of glaciers to measure. We head out in a Land Rover Discovery across the treeless, craggy, doom-laden landscape, in which people, or, for that matter, all life forms, even grass, seem out of place. Mars on Earth. “You have to remember, Iceland, except in the highlands, looks like the ocean floor,” Jim says. “Now, what if I were Spock in ‘Star Trek,’ looking at the Earth from the Starship Enterprise? Captain Kirk says, ‘Spock, what do you see? Put the scanners on.’ I’d say, ‘I see a watery planet. It’s a planet dominated by oceans.’ The land is an insignificant fraction of what makes up this planet. If we could peel away the water and look at the Earth from space, planetary scientists would say, ‘I see what the Earth does. It has a large system of very thin crustal blocks that are moving and being eaten up in some places and being regenerated in others.’”

Jim catches his breath and swerves to avoid a small herd of scrawny Icelandic sheep. “Now we are starting to add a tapestry of new measurements from Mars Global Surveyor, as we try to understand all these different surface units on Mars. Scientists want to find hot pits, if there are any, just like the ones you saw on Surtsey. Now, how big were they on Surtsey?”

Just a few inches wide, I remind him, and he points out that it would be very difficult to see such tiny formations from space, even at high resolution. “You would need an extremely sensitive thermal scanner in orbit.” Such a device actually exists, but it would not, on its own, be able to detect alien life. Scientists also look for biomarkers, that is, distinctive signatures of life. And they seek signs of an energy or nutrient system capable of sustaining life. “On Mars, we want to find playas, dried up sea-beds, where there might have been standing bodies of water. We see playas on Earth, in the dried lake beds of the western United States, the dry lakes of Australia. On Mars, these playas may be even bigger. The topography measured by the laser going around Mars can find those areas for us.” So playas may hold clues to life on Mars, and volcanoes may also lead scientists to Martian gardens of Eden. It may just be Garvin’s bias, because he is crater expert, but he thinks volcanoes are an important component in the design for living – another reason that Iceland appeals to him. “Iceland has volcanoes that are active, with ice, certainly something that happened on Mars. We have volcanoes interacting with ground water, very important, because there may be ground water on Mars. We don’t know. And we have volcanoes here producing new lava at great rates. Some of the volcanoes on Mars have sustained high eruption rates for hundreds or even thousands of years. That’s what it takes to make an Olympus Mons” – and Olympus Mons is so big that it couldn’t exist on Earth. “There’s too much gravity here, and anything aspiring to Olympus Mons-like grandeur would collapse under its own weight.” He likens its shape to the much smaller lava shield volcanoes of Iceland. The term is meant to suggest a Viking shield turned on its side; a lava shield volcano slopes very gently. “It’s the most common landform made by volcanism in the Solar System. Mother Nature does not know how to do it any simpler.”

Later, we coast past an immense, dry lake bed studded with pebbles. We get out and walk across its dusty surface. It would not be surprising to see a pterodactyl soar overhead, or a spacecraft descend from the skies. This is Nature’s rough draft, a land of possibilities. It’s not as polished as later versions, but the crude landscape yields its secrets and intentions to geologists. “When the water dries up, it leaves behind a lag deposit of rocks,” Jim remarks. The rocks range in size from small cobbles up to large boulders. “And anything bigger,” he announces, “is called a real big boulder! The bright stuff you see here is a layer of desiccated, cemented dust made of clay. That is what comes out of suspension when water evaporates. We expect to see signatures of that kind of stuff on Mars.” He points to a fissure in the soil. “See this desiccation crack? This is what we hope to see on Mars.”

We head north until we reach an enormous glacier: Langjökull. On the other side, its summit obscured by cloud cover, is the great volcano known as Ok. The stony, dusty ground, reddish brown, contrasts with the huge wall of ice. I slowly become aware of the landscape’s resemblance to images of the Martian icecaps, those vast dull white fields rising out of the reddish Martian desert. The more we look, the more striking the resemblance to the northern latitudes of Mars. Our isolation feels complete. No birds or cars disturb the pure silence. No airplanes streak by overhead; the atmosphere is untarnished by plumes of smoke. The spectral glacier rises impressively from the dark red rock, its façade reaching into the clouds and mist, massive, gloomy, impersonal, hypnotic. Nearly everything looks alien and supremely indifferent to the two tiny human figures in the midst of this vast, primeval sanctuary. Take all the measurements you want of Mars, but walking through this strange and unnerving place suggests, as nothing else can, what it would be like to traverse the surface of the Red Planet.