Sunrise on Pluto

We have waited out the night, and now at last we will go forth onto the frozen face of Pluto. One by one we take our places—Leonides, Sherrard, Gartenmeister, me—and ready ourselves to clamber down the ladder to the icy surface of the outermost of worlds.

Soon we will have an answer to the question that has obsessed us all during this long night.

Night on Pluto is 6.39 Earth-days long, and that night is blacker and colder than anything any of us has ever known. It is a true dark night of the soul, a dismal time made infinitely more terrible by our awareness of the monstrous distance separating us from all that we love. That distance imposes a burden which our spirits can scarcely carry. God knows, the dark side of Luna is a bleak and terrible place, but one never feels so wholly crushed by its bleakness as we have felt here. On Luna one need make only a brief journey to the edge and there is the lovely blue Earth hovering overhead, close, familiar, beckoning. But here stand we on forlorn Pluto, knowing that we are nearly four billion miles from home. No one has ever been so far from home before.

Now at last the fierce interminable night is ending. When we made our touchdown here the night was half spent; we used what remained of the dark hours to carry out our preliminary observations and to prepare for the extravehicular journey. Now, as we make ready to emerge, there comes the first trembling hint of a dawn. The utter and absolute and overwhelming darkness, which has been made all the more intense by the chilly glitter of the stars, is pierced by a strange pale glow. Then a sudden astonishing burst of light enters the sky—the light of a giant star whose cold radiance is hundreds of times as bright as that of the full moon seen from Earth.

It is the sun, our sun, the well of all warmth, the fountain of life. But how sadly its splendor is altered and diminished by those billions of miles! What reaches us here is not the throbbing golden blaze of summer but only a brilliant wintry beacon that sends glittering tracks of dazzling merciless brightness across the stark icefields of Pluto.

We move toward the hatch. No one speaks. The tension is rising and our faces show it.

We are edgy and uneasy, but not because we are about to be the first humans to set foot on this world: that is trivial, entirely unimportant to us, as I think it has always been to those who have carried the great quest outward into space. No, what concerns us is a mystery that no previous explorers of the Solar System have had to confront. Our instruments, during the long Plutonian night, have been recording apparent indications that living creatures, Plutonian life-forms, are moving about out there.

Life-forms? Here, on the coldest and most remote of worlds? It seems absurd. It is absurd. Nowhere in the Solar System has anyone ever found a trace of extraterrestrial life, not on any of the explored planets nor on any of their moons. Unless something unimaginable lurks deep within the impenetrable gaseous mantles of Jupiter or Saturn or Uranus, our own small planet is the sole repository of life in the System, and, for all we know, in the entire universe. But our scanners have picked up the spoor of life here: barely perceptible electromagnetic pulses that indicate something in motion. It is strictly a threshold phenomenon, the most minimal trace-output of energy, the tiniest trickle of exertion. The signal is so faint that Sherrard thinks it is nothing more than an instrumentation error, mere noise in the circuitry. And Gartenmeister wants it to be an error—he fears the existence of extraterrestrial life, so it seems, the way Pascal feared the eternal silence of the infinite heavens. Leonides argues that there is nothing that could produce such distinct vectors of electromagnetic activity except neural interaction, and therefore some sort of living beings must be crawling about on the ice-fields. “No,” I say, “they could be purely mechanical, couldn’t they? Robots left behind by interstellar explorers, say?”

Gartenmeister scowls at me. “Even more absurd,” he says.

No, I think, not more absurd, merely more disturbing. No matter what we discover out there, it is bound to upset deeply held convictions about the unique place of Earth in the cosmos. Who would have thought it, that Pluto, of all places, would harbor life? On the other hand, perhaps Sherrard is right. Perhaps what we have imagined to be life-forms emitting minuscule flickers of electrical energy is in truth nothing more than deceptive Brownian tremors in the atoms that make up our ship’s sensors. Perhaps. Soon we may have an answer.

“Let’s go,” Leonides says.

We swing downward and outward, into the cheerless Plutonian dawn.

The blackness of the sky is tinged with green as the distant sunlight bounces through the faint wispy swirls of methane that are Pluto’s atmosphere. Visible now overhead, hovering ominously close, is the dull menacing bulk of Charon, Pluto’s enormous moon, motionless and immense. Our shadows are weird things, sharp-edged and immensely long. They seem to strain forward as though trying to escape from us. Cold tendrils of sunlight glide unhurriedly toward the jagged icy cliffs in the distance.

Sunrise! Sunrise on Pluto!

How still it is, an alien sunrise. No birds sing, no insects buzz and drone. We four have seen many such sunrises—on Luna, on Mars, on Titan, on Ganymede, on Iapetus: standing with our backs to the rising sun, looking out on a harsh and silent landscape. But none so silent as this, none so harsh.

We fan out across the surface of Pluto, moving lithely, all but floating: Pluto is the lightest of worlds, its mass only a few hundredths that of Earth, and its gravitational grip is less secure than those of some of the larger moons. What do I see? Ice. A joyless methane sea far away, shining faintly by the dull light of dawn. Fangs of black rock. Despair begins to rise in me. To have come billions of miles, merely for the sake of being able to say that this world, too, has been explored—

“Here!” Leonides calls.

He is far in front of us, almost at the terminator line beyond which the sun has not yet reached. He is pointing ahead, into the darkness, stabbing at it with the beam of his light.

“Look! I can see them moving!”

We run toward him, leaping in great bounds, soaring, gliding. Then we stand beside him, following the line of his light, staring in awe and astonishment toward the darkness.

Yes. Yes. We have the answer at last to our question, and the answer is a stunning one. Pluto bears life. Small dome-shaped things are scrabbling over the ice!

They move slowly, unhurriedly, and yet one somehow feels that they are going as fast as possible, that indeed they are racing for cover, pushing their bodies to the limits. And we know what it is that they are struggling to escape; for already the ones closest to us have been overtaken by the advancing light of day, and as the rays touch them they move more slowly, and more slowly yet, and then they fall entirely still, stopping altogether between one moment and the next, like wind-up toys that have run down. Those that are in sunlight now lie stranded on the ice, and those ahead of them are being overtaken, one after another.

We hasten to them, kneel, examine them. None of us says a word. We hardly dare look at one another. The creatures are about the size of large crabs, with thick smooth waxy-textured gray shells that reveal neither eyes nor mouths. They are altogether motionless. I touch one with a trembling hand, nudge it, get no response, nudge it a bit more forcefully. It does not move. I glance at Leonides. He nods, and I tip the creature on its side, which shows us a great many small jointed legs that seem to sprout from the shell surface itself. What a simple creature! A mere armored box!

“I don’t believe it,” Sherrard mutters.

“You still think it’s an error in the circuitry?” Leonides asks him gently.

Sherrard shakes his head. Carefully he gathers one of the creatures into his gloved hands and brings it close to his faceplate. “It doesn’t move at all,” he says quietly. “It’s playing possum, isn’t it?”

“It may not be able to move,” says Leonides. “Not with anything as warm as you so close to it. They’re tremendously sensitive to heat, I imagine. You see how they start to shut down, the moment the sun strikes them?”

“Like machines,” says Sherrard. “At the wrong operating temperature they cease to function.”

“Like machines, yes,” Leonides replies. “But surely you aren’t going to try to argue that they are machines, are you?”

Sherrard shrugs. “Machines can have legs. Machines can have shells.” He looks toward me. “It’s like you said, Tom: robots left behind by explorers from some other part of the galaxy. Why not? Why the hell not?”

There is nothing to gain by debating it out here. We return to the ship to get collection chambers and scoop three of the creatures into cryotanks, along with liquid methane and lumps of frozen-ammonia ice. The discovery is so wholly unexpected and so numbing in its implications that we can hardly speak. We had thought we were making a routine reconnaissance of an unimportant planet; instead we have made one of the most astonishing discoveries in the history of science.

We store our finds in the ship’s lab at a temperature of two or three degrees Kelvin. Gartenmeister and Sherrard set about the job of examining them while Leonides and I continue the extravehicular exploration.

The crab-creatures are littered all over the place, dozens of them, hundreds, scattered like jetsam on a beach. They appear to be dead, but very likely Leonides’ notion that they are extremely heat-sensitive tells the real story: to the native life-forms of Pluto—and how strange it is to have a phrase like that running through my mind!—the coming of day must be an inexorable signal bringing a halt to all metabolic activity. A rise of just a few degrees and they are compelled to stop in their tracks, seemingly lifeless, in fact held in suspended animation, until the slow rotation of the planet brings them back, in another 6.39 Earth-days, into the frigid darkness that they must have in order to function. Creatures of the night: creatures of the inconceivable realm at the borderland of absolute zero. But why? It makes so little sense: to move by night, to go dormant at the first touch of the life-giving sun! Why? Why?

Leonides and I explore for hours. There is so much to do: collecting mineral samples, drilling for ice-cores that may yield data on earlier epochs of Pluto’s history, searching for other forms of life. We move carefully, for we are not yet used to the lightness of the gravitational field, and we prowl in a slow, systematic way, as if we are going to be the only expedition ever to land on this remote outpost of the Solar System and must take pains not to overlook anything. But I see the fallacy in that. It is true that this is the first time anyone has bothered to visit Pluto, although centuries have passed since the earliest human voyages into space. And it is true also that when we planned this expedition it was under the assumption that no one was likely to have reason to come this way again for a long time. But all that has changed. There is extraterrestrial life on this world, after all. Nowhere else is that the case. When we send back the news, it will alter the direction of virtually all scientific research, and much else besides.

The impact of our find is only just beginning to sink in.

Sherrard peers out of the ship’s lab as Leonides and I come back on board. His expression is a peculiar one, a mixture of astonishment and—what?—self-satisfaction?

“We’ve discovered how they work,” he announces. “They operate by superconductivity.”

Of course. Superconductivity occurs only within a few degrees of absolute zero: a strange and miraculous thing, that resistance-free flow of current, the most efficient possible way of transmitting an electrical signal. Why not have it serve as the energizing principle for life-forms on a world where nighttime temperatures drop to two degrees Kelvin? It seems so obvious, now that Sherrard has said it. But at the same time it is such an unlikely thing, such an alien way for living creatures to be designed. If, that is, they are living creatures at all, and not merely some sort of cunning mechanisms. I feel the hair lifting along the back of my neck.

Gartenmeister and Sherrard have dissected one. It lies on its back, its undershell neatly cut away and its internal organs exposed to view. Its interior is lined with a series of narrow glossy green and blue tubes that cross and meet at rigid angles, with small yellow hexagonal bodies spaced at regular intervals down the center. The overall pattern is intricate, yes, but it is the intricacy of a well-designed machine. There is an almost oppressive symmetry about the arrangement. A second creature, still intact, rests unmoving and seemingly lifeless in its holding tank. The third has been placed in an adjoining tank, and it is awake and sullenly scrabbling about like a trapped turtle trying to climb the walls of its bowl.

Jerking his thumb at the one that is moving, Gartenmeister says, “We’ve got it at Pluto-night temperature, just a notch above absolute. The other tank’s five degrees warmer. The threshold is very precise: when the temperature rises to seven degrees above absolute zero they start to go dormant. Lower the temperature and they wake up. Raise it again, they stop in their tracks again. It’s like throwing a switch.”

“It’s exactly like throwing a switch,” says Sherrard. “They’re machines. Very neatly calibrated.” He turns on a projector. Glittering cubical forms appear on the screen. “Here: look at the crystalline structure of one of these tubes. Silicon and cobalt, arranged in a perfect matrix. You want to tell me this is organic life? These things are nothing more than signal-processing devices designed to operate at super-cold temperatures.”

“And we?” Leonides asks. “Are we not merely signal-processing devices also, designed to operate in somewhat warmer weather?”

“Merely? Merely?”

“We are machines of flesh and blood,” says Leonides. “These are machines of another kind.”

“But they have blood also,” Gartenmeister says. “Of the sort that a superconductive life-form would have to have. Their blood is helium II.”

How startling that is—and yet how plausible! Helium II, that weird friction-free fluid that exists only at the lowest of temperatures—capable of creeping up the side of a glass vessel in defiance of gravity, of passing through openings of incredibly small size, of doing all manner of unlikely things—and of creating an environment in which certain metals become capable of superconductive propagation of electrical signals. Helium II “blood,” I realize, would indeed be an ideal carrier of nutrients through the body of a non-organic creature unable to pump a conventional fluid from one part of itself to another.

“Is that true?” Leonides asks. “Helium II? Actually?”

Gartenmeister nods. “There is no doubt of it.”

“Helium II, yes,” says Sherrard sullenly. “But it’s just lubricating fluid. Not blood.”

“Call it what you like,” Gartenmeister tells him. “I use only a metaphor. I am nowhere saying yet that they are alive.”

“But you imply—”

“I imply nothing!”

I remain silent, paying little attention to the argument. In awe and wonder I stare at the motionless creature, at the one that is moving about, and at the dissected one. I think of them out there on the Plutonian ice-fields, meandering in their unhurried way over fields of frozen methane, pausing to nibble at a hydrocarbon sundae whenever they feel the need for refreshment. But only during the night; for when their side of Pluto at last comes round to face the sun, the temperature will climb, soaring as high as 77 degrees Kelvin. They will cease motion long before that, of course—at just a few moments after dawn, as we have seen, when the day’s heat rises beyond those critical few degrees at which superconductivity is possible. They slip into immobility then until night returns. And so their slow lives must go, switching from on to off for—who knows?—thousands of years, perhaps. Or perhaps forever.

How strange, I think, how alien, how wonderful they are! On temperate Earth, where animal life has taken the form of protoplasmic oxygen-breathing beings whose chemistry is based on carbon, the phenomenon of superconductivity itself is a bizarre and alien thing, sustainable only under laboratory conditions. But in the unthinkable cold of Pluto, how appropriate that the life-forms should be fashioned of silicon and cobalt, constructed in flawless lattices so that their tissues offer no resistance to electrical currents. Once generated, such a current would persist indefinitely, flowing forever without weakening—the spark of life, and eternal life at that!

They still look like grotesque crabs to me, and not the machines that Sherrard insists they must be. But even if they are animals rather than machines, they are, by comparison with any life-form known to Earth, very machine-like animals indeed.

We have spent a wearying six hours. This discovery should have been exhilarating, even exalting; instead we find ourselves bickering over whether we have found living creatures or mere ingenious mechanisms. Sherrard is adamant that they are machines; Gartenmeister seems to lean in both directions at once, though he is obviously troubled by the thought that they may be alive; Leonides is convinced that we are dealing with true life-forms. I think the dispute, now overheated and ugly, is a mere displacement symptom: we are disturbed by the deeper implications of the find, and, unwilling thus far to face them directly, we turn instead to quarreling over secondary semantic technicalities. The real question is not who created these beings—whether they are the work of what I suppose we can call the divine force, or simply of other intelligent creatures—but how we are to deal with the sudden inescapable knowledge that we are not alone in the universe.

I think we may just have settled the life-versus-machine dispute.

It is morning, ship-time. Gartenmeister calls out sharply, waking us. He has been on watch, puttering in the lab, while we sleep. We rush in and he points to the Plutonian that has been kept at superconductive temperatures.

“See there? Along the lower left-hand rim of its shell?”

I can find nothing unusual at first. Then I look more carefully, as he focuses the laser lamp to cast its beam at a steeper angle. Now I observe two fine metallic “whiskers,” so delicate that they are barely visible even to my most intense scrutiny, jutting to a length of five or six millimeters from the edge of the shell.

“I saw them sprout,” he says. “One came half an hour ago. The other just now. Look—here comes a third!”

We crowd in close. There can be no doubt: a third delicate whisker is beginning to protrude.

Sherrard says, “Communications devices, perhaps? It’s programmed to signal for help when captured: it’s setting up its antenna so that it can broadcast to the others outside.”

Leonides laughs. “Do you think they get captured often? By whom?”

“Who can say?” Sherrard responds. “There may be other creatures out there that prey on—”

He stops, realizing what he has said. It is too late.

“Other creatures?” I ask. “Don’t you mean bigger machines?”

Sherrard looks angry. “I don’t know what I mean. Creatures, machines—” He shakes his head. “Even so, these might be antennae of some sort, can’t they? Signalling devices that protrude automatically in time of danger? Say, when one is trapped by an ice-slide?”

“Or sensors,” offers Leonides. “Like a cat’s whiskers, like a snail’s feelers. Probing the environment, helping it to find a way out of the tank we’ve got it in.”

“A reproductive organ,” Gartenmeister says suddenly.

We stare at him. “What?”

Unperturbed, he says, “Many low-phylum life-forms, when they are trapped, go automatically into reproductive mode. Even if the individual is destroyed, the species is still propagated. Let us say that these are living creatures, yes? For the sake of argument. Then they must reproduce somehow. Even though they are slow-growing, virtually immortal, they must still reproduce. What if it is by budding? They take in minute quantities of silicon and cobalt, build up a surplus of nutrients, and at a certain time they put forth these filaments. Which gain in size over—who knows, a hundred years, a thousand, ten thousand?—and when they have the requisite minimum mass, they break free, take up independent life, foraging for their own food. The electrical spark of life is transferred automatically from parent to offspring, and sustains itself by means of their superconductivity.”

We look at him in amazement. Obviously he has been pondering deeply while we were sleeping.

“If you tell us that they metabolize—they eat, they transfer nutrients along the flow of helium II, they even reproduce,” says Leonides, “then you’re telling us that they’re living things.

Or else you’re asking us to redefine the nature of machines in such a way as to eliminate any distinction between machines and living things.”

“I think,” says Gartenmeister in a dark and despondent tone, “that there can be no doubt. They are alive.”

Sherrard stares a long while at the three tiny filaments. Then he shrugs.

“You may be right,” he says.

Leonides shakes his head. “Listen to you! Both of you! We’ve made the most exciting discovery in five hundred years and you sound as though you’ve just learned that the sun’s going nova tomorrow!”

“Let them be,” I tell him, touching his arm lightly. “It’s not easy.”

“What’s not?”

“A thousand years ago everyone thought the earth was at the center of the universe, with everything else moving in orbit around it,” I say. “It was a very comfortable and cozy and flattering idea, but it didn’t happen to be true, as Copernicus and Kepler and Galileo were able to prove. It was such a hard thing for people to accept that Galileo was put on trial and forced to deny his own findings, wasn’t he? All right. In time everyone came to admit that the earth moves around the sun, and not vice versa. And now, for centuries, we’ve explored space and found it absolutely lifeless—not a smidgeon of life, not a speck, no Martians, no Venusians, no Lunarians, nothing. Nothing. Earth the cosmic exception, the sole abode of life, the crown of creation. Until now. We have these little superconductive crabs here on Pluto. Our brothers-in-life, four billion miles away. Earth’s last uniqueness is stripped away. I think that’ll be harder to swallow than you may think. If we had found life right away, on the Moon back in the twentieth century, on Mars a little later on, it might have been easier. But not now, not after we’ve been all over the System. We developed a sort of smugness about ourselves. These little critters have just destroyed that.”

“Even if they are machines,” says Gartenmeister hollowly, “then we have to ask ourselves: Who built them?”

“I think I’d prefer to think they’re alive,” Sherrard says.

“They are alive,” I tell them. “We’re going to get used to that idea.”

I walk to the hatch and peer outside. Small dark shapes lie huddled motionless here and there on the ice, waiting for night to return. For a long while I stare at them. My soul is flooded with awe and joy. The greatest of miracles has happened on this planet, as it had happened also long ago on Earth; and if life has been able to come into being on dismal Pluto, I know we will encounter it on a million million other worlds as we make our way in the centuries to come beyond this little Solar System into the vast galaxy. Somehow I cannot find anything to fear in that thought. Suddenly, thinking of the wonders and splendors that await us in that great beyond, I imagine that I hear the jubilant music of the spheres resounding from world to world; and when I turn and look back at the others, I realize that they also have been able to move past that first hard moment of shock and dismay which the loss of our uniqueness has brought. I see their faces transfigured, I see the doubt and turmoil gone; and it seems to me that they must be hearing that music too.