The Space Trilogy

by Arthur C. Clarke

  Even the Commander unbent more than I'd ever known him to before—not that he was ever really formidable once you'd got used to him. But he never talked about himself; and back at the Inner Station no one would have dreamed of asking him to tell the story of his part in the first expedition to Mercury. And if they had, he certainly wouldn't have done so—yet he did now. He grumbled for a while, but not very effectively. Then he began to talk.

  'Where shall I start?' he mused. 'Well, there's not much to say about the voyage itself—it was just like any other trip. No one else had ever been so near the Sun before, but the mirror-plating of our ship worked perfectly and stopped us getting too hot by bouncing eighty per cent of the Sun's rays straight off again.

  'Our instructions were not to attempt a landing unless we were quite sure it would be safe. So we got into an orbit a thousand miles up and began to do a careful survey.

  'You know, of course, that Mercury always keeps one face towards the Sun, so that it hasn't days or nights as we have on Earth. One side is in perpetual darkness—the other in blazing light. However, there's a narrow 'twilight' zone between the two hemispheres, where the temperature isn't too extreme. We planned to come down somewhere in this region, if we could find a good landing place.

  'We had our first surprise when we looked at the day side of the planet. Somehow everyone had always imagined that it would be very much like the Moon—covered with jagged craters and mountain ranges. But it wasn't. There are no mountains at all on the part of Mercury directly facing the Sun—only a few low hills and great, cracked plains. When we thought about it, the reason was obvious. The temperature down there in that perpetual sunlight is over seven hundred degrees F. That's much too low to melt rock—but it can soften it, and gravity had done the rest. Over millions of years, any mountains that might have existed on the day side of Mercury had slowly collapsed, just as a block of pitch flows on a hot day. Only round the rim of the night land, where the temperature was far lower, were there any real mountains.

  'Our second surprise was to discover that there were lakes down there in that blazing inferno. Of course, they weren't lakes of water, but of molten metal. Since no one's been able to reach them yet we don't know what metals they are—probably lead and tin, with other things mixed up with them. Lakes of solder, in fact! They may be pretty valuable one day, if we can discover how to tap them.

  'As you'll guess from this, we weren't anxious to land anywhere in the middle of the day side. So when we'd completed a photographic map we had a look at the Night Land.

  'The only way we could do that was to illuminate it with flares. We went as close as we dared—less than a hundred miles up—and shot off billion-candle-power markers one after another, taking photographs as we did so. The flares, of course, shared our speed and travelled along with us until they burned out.

  'It was a strange experience, knowing that we were shedding light on a land that had never seen the Sun—a land where the only light for maybe millions of years had been that of the stars. If there was any life down there—which seemed about as unlikely as anything could be—it must be having quite a surprise! At least, that was my first thought as I watched our flares blasting that hidden land with their brilliance. Then I decided that any creatures of the Night Land would probably be completely blind, like the fish of our own ocean depths. Still, all this was fantasy: nothing could possibly live down there in that perpetual darkness, at a temperature of almost four hundred degrees below freezing point. We know better now, of course…

  'It was nearly a week before we risked a landing, and by that time we'd mapped the surface of the planet pretty thoroughly. The Night Land, and much of the Twilight Zone, is fairly mountainous, but there were plenty of flat regions that looked promising. We finally chose a large shallow bowl on the edge of the Day Side.

  'There's a trace of atmosphere on Mercury, but not enough for wings or parachutes to be of any use. So we had to land by rocket braking, just as you do on the Moon. However often you do it, a rocket touchdown is always a bit unnerving—especially on a new world where you can't be perfectly sure that what looks like rock is anything of the sort.

  'Well, it was rock, not one of those treacherous dust-drifts they have on the Moon. The landing gear took up the impact so thoroughly that we hardly noticed it in the cabin. Then the motors cut out automatically and we were down—the first men to land on Mercury. The first living creatures, probably, ever to touch the planet.

  'I said that we'd come down at the frontiers of the Day Side. That meant that the Sun was a great, blinding disc right on the horizon. It was strange, seeing it almost fixed there, never rising or setting—though because Mercury's got a very eccentric orbit, the Sun does wobble to and fro through a considerable arc in the sky. Still, it never dropped below the horizon, and I always had the feeling that it was late afternoon and that night would fall shortly. It was hard to realize that "night" and "day" didn't mean anything here…

  'Exploring a new world sounds exciting, and so it is, I suppose. But it's also darned hard work—and dangerous, especially on a planet like Mercury. Our first job was to see that the ship couldn't get overheated: we'd brought along some protective awnings for this purpose. Our "sunshades", as we called them. They looked peculiar—but they did the job properly. We even had portable ones, like flimsy tents, to protect us if we stayed out in the open for any length of time. They were made of white nylon and reflected most of the sunlight, though they let through enough to provide all the warmth and light we wanted.

  'We spent several weeks reconnoitring the Day Side, travelling up to twenty miles from the ship. That may not sound very far, but it's quite a distance when you've got to wear a space-suit and carry all your supplies. We collected hundreds of mineral specimens and took thousands of readings with our instruments, sending back all the results we could by tight-beam radio to Earth. It was impossible to go far enough into the Day Side to reach the lakes we'd seen—the nearest was over eight hundred miles away, and we couldn't afford the rocket fuel to go hopping around the planet. In any case it would have been far too dangerous to go into that blazing furnace with our present, untried equipment.'

  The Commander paused, staring thoughtfully into space as if he could see beyond our cramped little cabin to the burning deserts of that distant world.

  'Yes,' he continued at last, 'Mercury's quite a challenge. We can deal with cold easily enough, but heat's another problem. Yet I suppose I shouldn't say that, because it was the cold that got me, not the heat…

  'The one thing we never expected to find on Mercury was life, though the Moon should have taught us a lesson. No one had expected to find it there, either. And if anyone had said to me, "Assuming that there is life on Mercury, where would you hope to find it?" I'd have replied, "Why, in the Twilight Zone, of course." I'd have been wrong again…

  'Though no one was very keen on the idea, we decided we ought to have at least one good look at the Night Land. We had to move the ship about a hundred miles to get clear of the Twilight one, and we landed on a low, flat hill a few miles from an interesting-looking range of mountains. We spent an anxious twenty-four hours before we were sure that it was safe to stay. The rock on which the ship was standing had a temperature of minus three hundred and fifty degrees, but our heaters could handle the situation. Even without them on, the temperature in the ship dropped very slowly, because of course there was a near vacuum round us and our silvered walls reflected back most of the heat we'd lose by radiation. We were living, in fact, inside a large Thermos flask—and our bodies were also generating quite a bit of heat.

  'Still, we couldn't learn much merely by sitting inside the ship: we had to put on our space-suits and go out into the open. The suits we were using had been tested pretty thoroughly on the Moon during the lunar night, which is almost as cold as it is on Mercury. But no test is ever quite like the real thing. That was why three of us went out. If one man got into trouble, the other two could get him back to the ship we
hoped.

  'I was in that first party: we walked slowly round for about thirty minutes, taking things easily and reporting to the ship by radio. It wasn't as dark as we'd expected, thanks to Venus. She was hanging up there against the stars, incredibly brilliant, and casting easily visible shadows. Indeed, she was too bright to look at directly for more than a few seconds: using a filter to cut down the glare, one could easily see the tiny disc of the planet.

  'The Earth and Moon were also visible, forming a beautiful double star just above the horizon. They also gave quite a lot of light so we were never in complete darkness. But, of course, neither Venus nor Earth gave the slightest heat to this frozen land.

  'We couldn't lose the ship, because it was the most prominent object for miles around and we'd also fixed a powerful beacon on its nose. With some difficulty we broke off a few small specimens of rock and carried them back with us. As soon as we took them into the air-lock, an extraordinary thing happened. They became instantly covered with frost, and drops of liquid began to form on them, dripping off to the floor and evaporating again. It was the air in the ship condensing on the bitterly cold fragments of stone. We had to wait half an hour before they had become sufficiently warm to handle.

  'Once we were sure that our suits could withstand the conditions in the Night Land, we made longer trips, though we were never away from the ship for more than a couple of hours. We hadn't reached the mountains yet—they were just out of range. I used to spend a good deal of time examining them through the electronic telescope in the ship—there was enough light to make this possible.

  'And one day, I saw something moving. I was so astonished that for a moment I sat frozen at the telescope, goggling foolishly through the eye-piece. Then I regained enough presence of mind to switch on the camera.

  'You must have seen the film. It's not very good, of course, because the light was so weak. But it shows the mountain wall with a sort of landslide in the foreground—and there's something large and white scrabbling round among the rocks. When I saw it first it looked like a ghost and I don't mind saying that it scared me. Then the thrill of discovery banished every other feeling and I concentrated on observing as much as I could.

  'It wasn't a great deal, but I got the general impression of a roughly spherical body with at least four legs. Then it vanished, and though I waited for half an hour it never reappeared.

  'Of course we dropped everything else and had a council of war. It was lucky for me that I'd taken the film, as otherwise everyone would have accused me of dreaming. We all agreed we must try and get near the creature: the only question was whether it was dangerous.

  'We had no weapons of any kind, but the ship carried a flare pistol which was intended for signalling. If it did nothing else, this should frighten any beast that attacked us. I carried the pistol, and my two companions—Borrell, the navigator, and Glynne, the radio operator—had a couple of stout bars. We also carried cameras and lighting equipment in the hope of getting some really good pictures. We felt that three was about the right number for the expedition: fewer might not be safe and—well, if the thing was really dangerous, sending the whole crew would only make matters worse.

  'It was five miles to the mountains, and it took us about an hour to reach them. The ship checked our course over the radio and we had an observer at the telescope, keeping a search in the neighbourhood so that we'd have some warning if the creature turned up. I don't think we felt in any danger: we were all much too excited for that. And it was difficult to see what harm any animal could do to us inside the armour of our space-suits—as long as the helmets didn't get cracked. The low gravity, and the extra strength that it gave us, added to our confidence.

  'At last we reached the rock slide—and made a peculiar discovery. Something had been collecting stones and smashing them up: there were piles of broken fragments lying around. It was difficult to see what this meant, unless the creature we were seeking actually found its food among the rocks.

  'I collected a few samples for analysis while Glynne photographed our discovery and reported to the ship. Then we started to hunt around, keeping close together in case of trouble. The rock slide was about a mile across: it seemed that the whole face of the mountain had crumbled and slid downwards. We wondered what could have caused this, in the absence of any weather. Since there was no erosion, we couldn't guess how long ago the slip had occurred. It might have been a million years old—or a billion.

  'Imagine us, then, scrambling across that jumble of broken rocks, with Earth and Venus hanging overhead like brilliant beacons, and the lights of our ship burning reassuringly down on the horizon. By now I had practically decided that our quarry must be some kind of rock-eater, if only because there seemed no other kind of food on this desolate planet. I wished I knew enough about minerals to determine what substance this was.

  Then Glynne's excited shout rang in my earphones.

  "'There it is!" he yelled. "By that cliff over there!"

  'We just stood and stared, and I had my first good look at a Mercurian. It was more like a giant spider than anything else—or perhaps one of those crabs with long, spindly legs. Its body was a sphere about a yard across, and was a silvery white. At first we thought it had four legs, but later we discovered that there were actually eight—a reserve set being carried tucked up close to the body. They were brought into action when the incredible cold of the rocks began to creep too far up the thick layers of insulating horn which formed its feet or hooves. When the Mercurian got cold feet, it switched to another pair!

  'It also had two handling limbs, which at the moment were busily engaged in searching among the rocks. They ended in elaborate, horny claws or pincers which looked as if they could be dangerous in a fight. There was no real head, but only a tiny bulge on the top of the spherical body. Later we discovered that this housed two large eyes, for use in the dim starlight of the Night Land, and two small ones for excursions into the more brilliantly illuminated Twilight Zone—the sensitive large eyes then being kept tightly shut.

  'We watched, quite fascinated, while the ungainly creature scuttled among the rocks, pausing now and again to seize a specimen and smash it to powder with those efficient-looking claws. Then something that might have been a tongue would flash out, too swiftly for the eye to follow, and the powder would be gobbled up.

  '"What do you think it's after?" asked Borrell. "That rock seems pretty soft. I wonder if it's some kind of chalk?"

  '"Hardly," I replied. "It's the wrong colour—and chalk's only formed at the bottom of seas, anyway. There's never been free water on Mercury."

  '"Shall we see how close we can get? " said Glynne. "I can't take a good photo from here. It's an ugly-looking beast, but I don't think it can do us any harm. It'll probably run a mile as soon as it sees us."

  'I gripped the flare pistol more firmly and said: "O.K.—let's go. But move slowly, and stop as soon as it spots us."

  'We were within a hundred feet before the creature showed any signs of interest in us. Then it pivoted on its stalk-like legs and I could see its great eyes looking at us in the faint moon-glow of Venus. Glynne said, "Shall I use the flash? I can't take a good picture in this light."

  'I hesitated, then told him to go ahead. The creature gave a start as the brief explosion of light splashed over the landscape, and I heard Glynne's sigh of relief. "That's one picture in the bag, anyway! Wonder if I can get a close-up? "

  '"No," I ordered, "that would certainly scare it—or annoy it, which might be worse. I don't like the look of those claws. Let's try and prove that we're friends. You stay here and I'll go forward. Then it won't think we're ganging up on it."

  "Well, I still think the idea was good—but I didn't know much about the habits of Mercurians in those days. As I walked slowly forward the creature seemed to stiffen, like a dog over a bone—and for the same reason, I guessed. It stretched itself up to its full height, which was nearly eight feet, and then began to sway back and forth slightly, looking very
much like a captive balloon in a breeze.

  "'I should come back!" advised Borrell. "It's annoyed. Better not take any chances."

  '"I don't intend to," I replied. "It's not easy to walk backwards in a space-suit, but I'm going to try it now."

  'I'd retreated a few yards when, without moving from its position, the creature suddenly whipped out one of its arms and grabbed a stone. The motion was so human that I knew what was coming and instinctively covered my visor with my arm. A moment later something struck the lower part of my suit with a terrific crash. It didn't hurt me, but the whole carapace vibrated for a moment like a gong. For an anxious few seconds I held my breath, waiting for the fatal hiss of air. But the suit held, though I could see a deep dent on the left thigh. The next time I might not be so lucky, so I decided to use my "weapon" as a distraction.

  'The brilliant white flare floated slowly up towards the stars, flooding the landscape with harsh light and putting distant Venus to shame. And then something happened that we weren't to understand until much later. I'd noticed a pair of bulges on either side of the Mercurian's body, and as we watched they opened up like the wing-cases of a beetle. Two wide, black wings unfurled—wings, on this almost airless world! I was so astonished that for a moment I was too surprised to continue my retreat. Then the flare slowly burned itself out, and as it guttered to extinction the velvet wings folded themselves and were tucked back into their cases.

  'The creature made no attempt to follow, and we met no others on this occasion. As you can guess, we were sorely puzzled, and our colleagues back in the ship could hardly credit their ears when we told them what had happened. Now that we know the answer, of course, it seems simple enough. It always does…