Antarctica

by Gabrielle Walker

  More than a decade later, debate is still raging. But although most scientists remain sceptical about the claims for Martian life in the rock, nobody has yet managed to prove beyond all doubt that ALH84001 has no traces of life. At first it seemed as though the carbonates must have formed at temperatures that were far too high to allow the existence of life, but, no, they could also have formed at comfortably low temperatures. The wiggles that looked like worms were too small to be bacteria, except that we have now found similarly small ‘nanobacteria’ on Earth. The organic chemicals could easily be formed by perfectly normal chemistry that has nothing to do with life. But they are also a natural by-product of life itself. ALH84001 is far from conclusive. But it is still the most intriguing evidence to date that life might have existed elsewhere in space, that we humans may not be alone.

  And if this proves to be right, there is a fascinating corollary. The earliest days of the Solar System were like a celestial billiards game with half-formed planetoids slamming into each other. Most scientists agree that life could not begin on Earth until this early bombardment had calmed down, and the rocks had stopped melting and the atmosphere had stopped boiling away. However, the evidence suggests that life started on Earth immediately after the bombardment ended. Which begs the question: how did life get its toehold on Earth the very moment that conditions were right?

  Perhaps the answer lies elsewhere in the Solar System. Mars is much smaller than the Earth, and its weaker gravitational pull would have attracted fewer incoming missiles. For it, the bombardment would have finished earlier, and thus life could have arisen earlier. And if life did appear on Mars in its earliest days and if (as we now know to be true) meteorites can be chipped off Mars and carried to Earth, could some of those rocks from space have brought Martian life along with them? If so, life might have evolved just once in the Solar System—on the planet Mars—and then come belatedly to Earth on the wings of an incoming rock or two. If that is true, and thanks to all that we have learned from Antarctica, we might all of us be Martians.

  Mars, Mars, Mars: you hear about it everywhere in the Dry Valleys. But the most Mars-like of all is a remote valley tucked up against the edge of the ice sheet, almost level with the Allan Hills. It is hard to reach, almost hidden by the bright white ice that all but surrounds it.

  Beacon Valley is an elongated horseshoe, protected by a semicircle of mountains, its flat northern edge disappearing seamlessly into the interlocking system of valleys and glaciers that stretches all the way down to the sea. It lies in the upland region of the Dry Valleys, the coldest, driest, most desolate part. And it is not just the closest place to Mars that humans have ever seen. It is also a valley where time stands still.

  From above, Beacon Valley’s floor looks like the scaly skin of a crocodile, or perhaps the cracked mud from a dried-out river bed. While the other Dry Valleys are smooth, this one is shot through with many-sided shapes that look too regular to have formed by chance. They are called ‘contraction-crack polygons’ and they show up in small patches in many cold, bleak parts of the world. But here they stretch for miles, the defining characteristic of an otherwise bare valley floor.

  Through my helicopter window the polygons looked so small and tidy that it was a shock to land and find that they were metres wide; so wide, in fact, that at eye level you could no longer make out the patterns. They seemed instead like random jumbles of rocks, set in shifting gravel and silt, with no discernible purpose but to turn your ankles and bar your way. The pilot had been in radio contact with my hosts and told me they were expecting me. ‘They’re over there somewhere,’ he said with a grin and a jerk of his thumb.

  As I watched him take off, I was feeling a bit bleak myself. The helicopter pad was just a small square in the middle of a polygon, with some of the biggest stones removed to make it flat. In the centre was an ‘x’ formed of yellow sandstones that stood out against the grey; the edges were marked with red tent bags weighted down with more stones. Just beyond were three pyramidal Scott tents, two yellow, one white, a few smaller dome tents and a large, brightly striped Endurance model that was probably where they cooked. There was no sign of anyone in camp. I was tempted for a moment just to stay there and wait for the end of the day, but I resolutely dumped my sleeping gear and stumbled off in search of the field party.

  I’d come to meet a double act of scientists, a partnership that Peter Doran described to me as a ‘match made in heaven’. The leader of this expedition was Dave Marchant from Boston University.14 Dave was an expert on geomorphology—the shape and structure of ice-formed landscapes—and he knew this particular landscape as well as anyone alive. With him would be Jim Head, from Brown University in Rhode Island, who was a world expert on Mars. According to both of them, Beacon Valley was the most Martian of the Dry Valleys, the closest you could get to the Red Planet without leaving Earth.15

  To be sure, the rocks I was stumbling over reminded me of the famous pictures from NASA’s missions to Mars. There were boulders everywhere, with polished sides like gemstones, and slightly rounded edges where they had been shaped by the wind. The winds must be strong here. Some of the more exposed ones had a scooped-out hollow in the gravel in front of them, and a long drawn-out gravel tail behind. Many of the rocks were pitted with holes that had been scoured by a combination of wind, salt and sand. I watched, fascinated, as a stray flake of snow landed on one of these pits and bounced from one side to the next before it finally settled and melted.

  The polishing by the wind had varnished these boulders, giving them a rust colour that looked even redder through my sunglasses. I sat for a moment with my back against a boulder and imagined that I was on Mars. The gravity was too strong, but I tried to let go of that. I pictured a pink sky, alien moons, Earth as a distant neighbour. The first overwhelming impression was one of loneliness. I shook myself and stood up. Maybe I overdid it. But now, a feeling of responsibility had kicked in. If I were really on Mars, then anything I touched had never been touched before. I started jumping from rock to rock like a child avoiding the cracks, so that I didn’t leave any footprints on the soft gravel. On this ridged landscape, I could see nobody else in the entire valley. It was foolish, but I suddenly needed to climb up on to one of the highest ridges of the nearest polygon and peer out ahead until I caught sight of a handful of red coats in the distance and felt a rush of relief.

  As I stumbled over the polygon rocks towards them I heard a mighty thwack. A figure in a red parka and jaunty green hat had slammed a sledgehammer against a small square of aluminium on the ground in front of him. The plate rose into the air with a silver flash like a leaping salmon and from where I was standing I heard two distinct ‘tings’ as the sound reached me first through the ground and then through the air. Two other figures were operating monitoring equipment and a handful more were looking on. The man with the hammer turned out to be Dave Marchant. When he saw me, he put the hammer on the ground. ‘OK, men!’ he barked in a mock-military tone though there were clearly women in his team. ‘Five minutes. Smoke if you’ve got ’em. Check your socks. If you’ve got a buddy make sure he’s OK.’ His students were clearly used to this. They grinned, stood down from the equipment and started pulling chocolate bars out of their backpacks.

  Dave was an odd combination of the light-hearted and intense. He was in his forties, his face deeply tanned and crinkled with laughter lines. His eyes were strikingly blue. He worked so hard and relentlessly that his students called him, to his face, ‘Cyborg’. But he required little persuasion to tear open his parka and fleece and show off the T-shirt he often wore underneath, bearing a picture of his infant son with the same striking blue eyes.

  While the rest of the crew took their break, Dave climbed with me over the boulders, pointing out his favourite features of this, his favourite valley. The main thing he wanted to show me was how it defied the normal rules. The one constant on earthly landscapes is usually change. Our home planet is restless and the continual assault of wind and w
eather, water and ice, is what shapes its surface.

  But not here. Dave calls this landscape ‘paralysed’. There has been no running water in Beacon Valley for fourteen million years. Most of the snow on the ground has blown in from elsewhere rather than fallen from the clouds. The wind may scoop and pit the boulders but it doesn’t move them. ‘You see that rockfall over there?’ He was pointing to a large skirt of rocks and boulders that had tumbled down from the mountain across the way. The rocks lay neatly where they had fallen, just as you’d expect from a fresh young landslide. If it had happened long ago, they should have been shuffled and shifted, confusing that neatly sloping pattern. ‘It looks recent, doesn’t it?’ said Dave. ‘Well, we’ve dated it and it’s a million years old!’

  He was delighted by my look of confusion, and walked over to where a small rock was sitting on the gravel. ‘Think about it,’ he said. ‘My family is religious, I went to church, heard about the time of Jesus two thousand years ago. Think of everything that has happened to the world since then, and through all that time this rock has just been sitting here. If I’d walked here a million years ago it would have looked like this. Ten million years ago, before humans ever walked anywhere, this is how this valley looked. It’s a window back in time.’

  The tectonic forces that cause the rest of the world to buckle and warp have been subdued here for an extraordinary stretch of time. ‘You’re looking at the most stable landscape on Earth,’ said Dave. ‘Nothing even comes close. The Grand Canyon was carved in its entirety; the alps in New Zealand have risen to their great heights and all the while nothing happened here.’

  I was awed by the sense that time was standing still there. And not just in the past but in the future, too. Though other parts of Antarctica might now be feeling the heat, Beacon Valley was insulated from almost everything. Only a big tectonic change—a clashing of continents that altered ocean circulations—would be likely to have an effect here. And that isn’t likely since the rest of the world’s continents are now all moving away. ‘We know what the future’s going to hold in Beacon Valley,’ said Dave, ‘and it’s more of the same.’

  And that’s what makes Beacon Valley Mars-like. Today, the Red Planet is old, cold and dry. Nothing moves; nothing changes. Just like here.

  As we walked, our bunny boots made striated oval footprints on the silt, like the ones Neil Armstrong left on the Moon. I told Dave about imagining myself on Mars, and then hopping from rock to rock on the way here so that I didn’t leave any violating human trace. He laughed. ‘This landscape isn’t just old, it’s also stable,’ he said. ‘So if you change something it wants to go back.’ He pointed to my space-man footprint. ‘The tread will be gone after one storm. The outline after a summer. And after a year, there will be no sign that it was ever there.’

  Back at the site, I met the other half of the scientific match. Jim Head appeared graver, with a soft, courteous Virginia accent. He was maybe twenty years older than Dave, and his white hair and beard, and the staff-like pole he was carrying, made him look like Gandalf, the wizard from The Lord of the Rings. Though he was the elder and more experienced of the two scientists, he was the guest here, and marked this, slightly self-mockingly, by calling Dave ‘sir’.

  Jim’s first job, just out of graduate school, was to advise the Apollo programme where to land on the Moon. (He said he had answered an advertisement that read: ‘Our job is to think our way to the Moon and back. Call this number.’) He had to choose somewhere that was interesting geologically to make the science of the mission worthwhile. But if the soil had been too soft in the Sea of Tranquillity, the Eagle could have sunk irrevocably into the lunar dust. If the ground had been sloping, the craft could have rolled. Buzz Aldrin and Neil Armstrong would have been tossed and tumbled inside their craft and their journey might have ended there. When the world watched on 20 July 1969, Jim’s daughters asked: ‘Where’s Dad?’ Dad, it turned out, was in a side room at the Apollo Control Center, watching and listening as the pictures rolled in. His choice of landing spot worked perfectly.16

  Since then he has been obsessed with planets. He talks about them with an easy familiarity, as though they are old friends. ‘On the Moon you could move along pretty fast. On Apollo 17 Jack [Schmitt] really got the lunar gait down. He practised a lot of different ways but the best one was hopping. There are some very funny pictures.’ What about Mars? ‘You probably wouldn’t hop on Mars,’ he says. ‘The Moon’s surface is much more forgiving, like a soft soil. On Mars you could launch yourself more than you wanted to and come crashing down. Trudging is the way to go there, pretty much the way we do it here.’

  I asked him what his favourite planet was. ‘The Earth,’ he said immediately. ‘But after that, Mars.’

  And that was why he was here, in this most Martian of places. Though he had trained astronauts for manned missions and robots for flights to Venus, Saturn and Mars, he had never walked on the planets he studied, or touched them, or tasted them. His job was to use his imagination. What should the astronauts collect? And later, what would the landers and rovers see? What should they pick up, or turn over, or test? How can you picture a landscape when all you had to go on was the rigid view of a robot camera?

  He started telling me about the Vallis Marinaris canyon system up on the Martian region of Tharsis. The canyon itself is vast, a single feature stretching the equivalent of the distance from Boston to Los Angeles. And yet, the resemblance to here is still uncanny. Beacon Valley is almost a montage of parts of Vallis Marinaris: the wind, the quiet, the ancient surface, the steep cliffs, the polygons and rocks that look just like those seen through the camera of the Viking lander.

  There is also the way the ice here tiptoes over the land without leaving a footprint. In most other icy parts of the world, glaciers are wet. They scrape along on a thin film of water, gouging out valleys and scratching the rocks as they pass. That’s what you get in the Alps, and the other places that have informed glaciologists and geologists for generations. But here, glaciers behave differently. They are old and cold and slow, and their bases are stuck to the ground. Instead of sliding, they flow sluggishly like treacle. They leave few scrape marks on the surface, but the piles of rocks they leave behind—formed as rocks fall from the cliffs on to their surfaces—look exactly like the ones on Mars.17

  When Dave first told Jim about Beacon Valley he was gobsmacked. ‘It was an epiphany for me. It was like, shht, that’s how it works on Mars, too!’ (He actually said ‘shht’. That’s how he pronounced it. Jim might mimic swear words but I can’t imagine him actually using one.)

  Now Jim was excited as he started reeling off the many ways that Beacon Valley reminded him of Mars. There was the lack of liquid water; the low erosion rates; the incredibly cold climate. Here in the upland zone of the Dry Valleys, he said, it was a hyper-dry cold polar desert. ‘And that’s what Mars is pretty much everywhere.’

  So though Jim was helping Dave investigate the scientific details of Beacon Valley’s surface, he was also on a training exercise for his imagination. ‘When you’re here you can walk around. You can look. You don’t have to wait for the wind data to come in, you can feel the wind. You see the way the light falls. You can immerse yourself in the landscape.’

  In his office in Brown University one of his students had painted a sign in calligraphy to hang on his wall. It bore one word: Daydream. ‘You know,’ he said, ‘in case I forget.’

  That evening, I discovered that Dave and Jim ran the most whimsical camp I had yet encountered. They used animal sounds for the wake-up call—a different one for each day. Tomorrow, Saturday, would be ‘Eee-awww’ which turned out to sound like a donkey with a bad hangover. Sunday would be the cawing of a crow and Monday, ambitious, this—‘a mockingbird imitation of a jay’. They named their thermos flasks according to a theme. This year, the theme was ‘obscure people’. Jim’s was named after Joe Engle, who was the astronaut kicked off the Apollo programme at the last minute to make way for Harrison �
��Jack’ Schmitt, ‘the only true geologist who’s ever been to space’.

  Toilet facilities were unusual, too. There were the normal pee bottles of the Dry Valleys, to be poured, when full, into a U-barrel. But for the rest, there was an arrangement little short of a throne. To use it you ‘declared’ in front of everyone, so there was no danger of subsequent embarrassment through the lack of lock, or indeed of door. A short stroll then took you to a sit-down box on the edge of the camp, set in the natural shelter of a small wall of boulders. To the right were age-old chocolate-coloured cliffs. In the distance, the folds and sweeps of the Taylor Glacier. Barring the few souls in the camp behind you the nearest human was hundreds, perhaps thousands, of kilometres away. This was a smallest room with the biggest, most majestic view.

  Though people slept in individual tents, the main activity centred around the cook tent, which contained two cots that doubled as couches, and two stoves on either side of the door. Hanging from the ceiling, among the defrosting dinner, plates, drying socks, gloves and hats, a cock-eyed Santa Claus and his spindly legged Rudolph, were two miniature speakers, precariously attached with duct tape beside an iPod cable. I’d brought fresh fruit and bread to try to win these guys over, but maybe fresh music would be a better idea. It was 8 p.m. now, and most of us were already in the tent, waiting for Dave to join us. Hesitantly I offered my iPod. ‘Are you looking for some new tunes?’ I asked. Conversation stopped. Someone said: ‘You don’t . . . by any chance . . . have any Tom Jones do you?’ Seven pairs of expectant eyes turned to me.

  As it happened, the answer was yes. I’d made my collection as eclectic as I could and now it looked as though it would pay off. Everyone was bizarrely excited. ‘Shh! Don’t say anything. Quick! Before he comes!’ Within a few minutes the first few bars of ‘It’s Not Unusual’ came belting out of speakers cranked up to top volume. Outside there was a roar. Dave ripped open the door and lurched into the tent, his eyes shining. Everyone was laughing and shouting at once. Eventually I discovered that Dave long ago declared this to be the official camp song; but someone took the CD last season and they’d been missing it like crazy. Tom Jones has no idea, I thought to myself. This was about as unusual as it got.