No one answered. Neptune loomed larger already, green monarch of the sea of space around them.
“It looks so big,” Beatryx said. “And — wild. Are you sure it’s safe?”
Groton smiled. “Neptune is seventeen or eighteen times as massive as Earth, but it is a lot less dense. What we see is not really the surface of the planet — it is the cloud cover. So it is large and wild, but don’t worry — we won’t try to land on it. We’ll take up orbit around it.”
“We’ll just love a year of free-fall,” Afra said.
Ivo watched the crumbs of their meal floating elusively in the currents of the forced-air circulation and knew what she meant. Free-fall was fun to visit, but not to stay. The space was too confined for long-term residence of four people, and muscles would atrophy in weightlessness if the body didn’t malfunction in other ways first. And keeping Brad aerated yet contained would be tedious, perhaps dangerous. The melting was supposed to be a high-gravity alleviant, and might be vulnerable to prolonged weightlessness.
No — an orbit around Neptune was no answer.
“How about Triton?” Groton said. “It’s about the size and mass of Mercury, I understand. Surface gravity should be about a quarter Earth-normal, and there might even be a little atmosphere. We’ll need a base of operations, if only to process hydrogen for the tanks. And it would be fairly simple to intercept Triton at this angle, since we’re coming up behind it.”
“That does sound very nice,” Beatryx said.
Groton was just warming up. “Now as I see it, our original purpose was to rescue the macroscope from deactivation or worse by the UN. To accomplish this it was necessary to remove the instrument from the immediate vicinity of Earth in a hurry. This much has been accomplished. Our main responsibility now is to keep ourselves advised of the situation at home, and to be ready to return the scope when the time is appropriate. Meanwhile, we can utilize the scope for reconnaissance.”
Ivo smiled. “You mean Super-Duper Poo—”
Afra quashed him with a glance. Oh, well. Call it reconnaissance or call it poop scooping, there was no sense going back blind.
“What’s this?” Afra demanded. They looked at her, startled. She had apparently been reorganizing her purse during the preceding dialogue, and now was looking at a page of a little stenographer’s notebook.
Ivo saw strange squiggles on the sheet.
“It’s in stenotype — a script version,” Afra said. “I never heard of such a thing! I use Gregg.”
“Oh, shorthand,” Groton said. “Can you make it out?”
Afra concentrated on the half-familiar symbols. “It doesn’t make much sense. It says ‘My pawn is pinned.’ ”
“Another message from Schön!” Beatryx exclaimed.
“He must have planted notes all over the station,” Groton said. “That polyglot, then the Neptune-symbol, and now this. He could have written them all at once and distributed them for us to find randomly—”
“But why didn’t he come to us directly?” Beatryx wanted to know. “If he was close enough to get into Afra’s purse—”
“Schön is devious,” Ivo said. But the explanation sounded insufficient, even to him. What other little surprises did the genius have in store for them?
Neptune had grown monstrously by the time the ship braked down to something resembling orbital velocity. The planet’s disk was fifteen times the apparent diameter of Luna from Earth, and its roiling atmospheric layers were horrendously evident. The great bands of color hardly showed now; instead there was a three-dimensional mélange of cloud and gas and turbulence suggesting a photograph of a complex of hurricanes. The spectators were still too far removed to perceive the actual motion, and could contemplate at leisure the awesome extent of the frozen detail.
Ivo felt as though he were peering into a cauldron of layered oils recently disturbed by heating. He had a vision of Brad’s basin perched on a furnace — and suppressed it, shocked at himself. Gray-blue bubbles a thousand miles across seemed to rise through the pooled, heavy gases, while slipstreams of turbulence trailed at the edges. In one place the recent passage of a bubble had left a beautifully defined cutaway section of gaseous strata, yellow layered on green on pink and black. In another, masses of whitish substance — hydrogen snow — were depressing the seeming ocean beneath, ballooning downward in a ponderous inversion. He was reminded of hot wax flowing into cool water.
No, there would be no landing in that.
Afra had retreated to the bowels of Joseph to supervise the maneuvering. They had cut inside Triton’s retrograde orbit and were overhauling the moon at a rate that was rapid in miles per hour but seemed slow because of the immensity of the scale. The thirty-one-thousand-mile disk of Neptune dwarfed everything, and its rainbow hues rendered its satellite drab.
Yet baby Triton had its share of intrigue. Only a tenth the diameter of Neptune, it was still one and a half times the span of Luna, and three and a half times Luna’s mass. Triton, mass considered, was the true giant of the moons of the Solar system, though there were others with a larger diameter. It expanded until its disk was the size of that of the mighty Neptune, then larger, and it was as though the two were sister planets. But where Neptune was stormy and bright, Triton was still and dark, from this angle. Its surface was tunelessly rigid.
“Rigid ridges,” Ivo murmured, half expecting Afra to say “What?” But she was not at hand.
There were craters: mighty broken rings of rock, shadowed in the middle, some pocked by smaller craters within. There were mountains: overlapping wrinkles across the surface. There was a brief atmosphere hazing the planetary outlines. And there were oceans.
“Must be some compound of oxygen and nitrogen,” Groton said. “Water is out of the question.” Intrigued, he had Ivo focus the macroscope on it and code in a spectroscopic analysis. “Atmosphere is mostly neon and nitrogen,” Groton said as he studied the result. “With a little oxygen and trace argon. The ocean is a liquefied compound of—”
Then they spied the object in space.
“Alert!” Groton snapped into the intercom. “We’re overhauling something, and I don’t mean Triton.”
“A ship?” Afra’s voice came back. “Schön?”
Ivo centered the small finder-telescope upon it. The thing leaped into focus: a fragment of matter about forty miles in diameter. “Too big,” he announced. “It’s rock or another solid — and it’s irregular.” He checked the specific indications, since they were passing it rapidly enough to measure parallax. “About fifty miles long, thirty-five wide at the thickest point.”
“I see it!” Afra cried. “We have it on Joseph’s screen now. We — that thing is in orbit!”
“Not around Neptune,” Groton protested. “It’s heading in toward the planet. Couldn’t—” He paused to take in his breath. “A moon of a moon? I don’t believe it.”
But it had to be believed. Due observation and analysis showed that it was a satellite of Triton, orbiting at about ten thousand miles distance with its broad side facing its primary. Its direction was “normal” — opposite to that of retrograde Triton. Its composition: H2O.
It was a solid mass of ice, so cold that its surface would be harder than steel — and at the edges it was translucent. The light of stars shone through it, separating into prismatic (though very faint) flashes of color, a constant peripheral display.
“What a beauty!” Afra exclaimed. “Whatever shall we name it?”