Ages ago, local heating had melted part of the glacier and formed Lake
Tuonela, almost as Stygian black as its parent but decorated by great whorls and loops where lighter material had been caught in patterns of turbulence, now frozen for eternity. Everyone who saw the phenomenon from the air for the first time thought he was being original when he exclaimed:
“Why, it looks exactly like a cup of coffee, just after you’ve stirred in the cream!”
As the sled raced over the lake, the pattern flickered past in a few minutes, too close for its swirls to be properly observed. Then there was another long slope, dotted with large boulders which could be avoided only by the full thrust of the under jets This cut speed to less than a hundred klicks, and the sled labored up toward the crest in zigs and zags, the driver cursing and looking every few seconds at his watch.
“There it is!” Duncan shouted.
Only a few kilometers away, coming out of the mist that always enveloped the flanks of Mount Shackelton, was a thin white line, like a piece of rope laid across the landscape. It stretched away downhill until it disappeared over the horizon, and the driver swung the sled around to follow its track.
But Duncan already knew that they were too late to achieve their main objective; they were much too close to World’s End. Minutes later, they were there, and the sled came to a stop at a respectful distance.
“That’s as close as I’m getting,” said the driver. “I wouldn’t like a gust to catch us when we’re skirting the edge. Who wants to go out?
We still have thirty minutes of light.” “What’s the temperature?” someone asked.
“Warm. Only fifty below. Single-layer suits will do.”
It was the first time that Duncan had been out in the open for months, but there were some skills that nobody who lived on Titan ever allowed himself to forget. He checked the oxygen pressure, the reserve tank, the radio, the fit of the neck seal-all those little details upon which his hopes of a peaceful old age depended. The fact that he would be within a hundred meters of safety, and surrounded by other men who could come to his aid in a moment, did not affect his thoroughness in the least.
Real spacers sometimes underestimated Titan, with disastrous results. It seemed altogether too easy to move around on a world where a pressure suit was unnecessary and the whole body could be exposed to the surrounding atmosphere. Nor was there any need to worry gbout freezing, even in the
Titanian night. As long as the thermosuit retained its integrity, the body’s own hundred and fifty watts of heat could maintain .a comfortable temperature indefinitely.
These facts could induce a sense of false security. A torn suit-which would be immediately noticed and repaired in a vacuum environment-might be ignored here as a minor discomfort until it was too late, and toes and fingers were quietly dropping off through frostbite. And although it seemed incredible that anyone could ignore an oxygen warning, or be careless enough to go beyond his point of no return, it had happened. Ammonia poisoning is not the nicest way to die.
Duncan did not let these facts oppress him, but they were always -there at the back of his mind. As he walked toward the worm, his feet crunching through a thin crust like congealed candle grease, he kept automatically checking the positions of his nearest companions, in case they needed him—or he needed them.
The cylindrical wall of the worm now loomed above him, ghostly white, textured with little scales or platelets which were slowly peeling off and falling to the ground. Duncan removed a mitten and laid his bare hand on the tube. It was slightly warm and there was a gentle
vibration; the core of hot liquid was still pulsing within, like blood through a giant artery. But the worm itself, controlled by the interacting forces of surface tension and gravity, had committed suicide.
While the others busied themselves with their measurements, photographs, and samples, Duncan walked to World’s End. It was not his first visit to that famous and spectacular view, but the impact had not diminished.
Almost at his feet, the ground fell away vertically for more than a thousand meters. Down the face of the cliff, the decapitated worm was slowly dripping stalactites of wax. From time to time an oily globule would break off and fall slowly toward the cloud layer far below. Duncan knew that the ground itself was another kilometer beneath that, but the sea of clouds that stretched out to the horizon had never broken since men had first observed it.
Yet overhead, the weather was remarkably clear. Apart from a little ethylene cirrus, nothing obscured the sky, and the sun was as sharp and bright as Duncan had ever seen it. He could even make out, thirty kilometers to the north, the unmistakable cone of Mount Shackelton, with its perpetual streamer of smoke.
“Hurry up and take your pictures,” said a voice in his radio. “You have less than five minutes.”
A million kilometers away, the invisible bulk of Saturn was edging toward the brilliant star that flooded this strange landscape with a light ten thousand times brighter than Earth’s full Moon. Duncan stepped back a few paces from the brink, but not so far that he could no longer watch the clouds below; he hoped he would be able to observe the shadow of the eclipse asit came racing toward him.
The light was going-going-gone. He never saw the onrushing shadow; it seemed that night fell instantly upon all the world.
He looked up toward the vanished sun, hoping to catch a glimpse of the fabled corona. But there was only a shrinking glow, revealing for a few seconds the curved edge of Saturn as the giant world swept
inexorably across the sky. Beyond that was a faint and distant star, which in another moment would also be engulfed.
“Eclipse will last twelve minutes,” said the hover sled driver. “If any of you want to stay outside, keep away from the edge. You can easily get disoriented in the darkness.”
Duncan scarcely heard him. Something had caught at his throat, almost as if a whiff of the surrounding ammonia had invaded his suit.
He could not take his gaze off that faint little star, during the seconds before Saturn wiped it from the sky. He continued to stare long after it was gone, with all its promise of warmth and wonder, and the storied centuries of its civilization.
For the first time in his life, Duncan Makenzie had seen the planet
Earth with his own unaided eyes. Part 11
I - -1 L Transit
I I
SIRIUS
After three hundred years of spaceships that were mostly fuel tanks,
Sirius was not quite believable. She seemed to have far too many windows, and there were entrance hatches in most improbable places, some of them still gaping open as cargo was loaded. At least she was taking on some hydrogen, thought Duncan sourly; it would be adding insult to economic injury if she made the round trip on a single fueling. She was capable of doing this, it was rumored, though at the cost of doubling her transit time.
It was also hard to believe that this stubby cylinder, with the smooth mirror-bright ring of the radiation baffle surrounding the drive unit like a huge sunshade, was one of the fastest objects ever built by man. Only the interstellar probes, now far out into the abyss on their centuries-long journeys, could exceed her theoretical maximum-almost one percent of the velocity of light. She would never achieve even half this speed, because she had to carry enough propel lent to slow down and rendezvous with her destination. Nevertheless, she could make the voyage from Saturn to Earth in twenty days, despite a minor detour to avoid the hazards-largely psychological-of the asteroid belt.