The Jupiter Theft

by Donald Moffitt

  “That's right. Eleven point two light-years away. There are only a dozen stars that are closer to us.”

  “If Dr. Ruiz's theory was correct...” He stopped till the pain disappeared from her face. “Then that must have been the Cygnans’ last stop before they headed for Earth. Our feathery zoo mates were the Cygnans’ most recent acquisition before us.”

  “But 61 Cygni was never considered to be a prime candidate for life.”

  “It is now.”

  “It's a double star, actually. The two suns are a K5 and a K7. Very weak. About six percent of the luminosity of our own sun. There wouldn't be much of a biosphere for habitat planets. Are you sure you understood the humanoids correctly?”

  “61 Cygni has a third component,” he prompted her.

  “But it isn't a star,” she said. “It's a nonluminous body. A planet. Actually, one of the first extra-solar planets to be discovered. It's a superjovian, with a mass about twelve times Jupiter's. It...” She stopped. “Oh.”

  “Exactly.”

  She swiveled back to the computer console so quickly that Jameson had to press her shoulder to push her back in her seat. Her hands scrabbled over the keys. Words tumbled out of her as she worked. “Dr. Ruiz transferred big chunks of the Farside computer's astronomical library to the ship's memory before we left Earth. He wanted to be sure we had updated data. The third component of 61 Cygni was discovered over a hundred years ago when they noticed some irregularities in the proper motion, of the binary. They started to discover a lot of extrasolar superjovians that way about then—most of them among the closer stars, of course. But nobody keeps tabs on them much any more. They get surveyed every few years in the automated sky sweeps, and if anybody wants to pull data out of the record for a graduate paper or anything, they can. Here we are. A check was made on it about five years ago, and then another just about a month before we launched this mission.”

  They both stared avidly at the data coming up on the screen. Jameson was unable to interpret the tables of astronomical figures. “What's it mean?” he said.

  “Five years ago 61 Cygni had its usual wobble. Now it doesn't.”

  “The superjovian's gone, then.”

  Maybury was going over the figures. “The Cygnans would have taken it a little more than eleven years ago. Its light ran ahead of them—but not by much of a margin. We would have seen the wobble until just before the Cygnans arrived—if we'd known enough to look for it.”

  Jameson looked out the viewport. The cast-off moons of Jupiter were now the brightest objects in the sky. They were tumbled carelessly across the night, like scattered dice, still rather close together. He picked out the biggest of them, a smooth white ball, the apparent size of a golfball, that had captured its own marble-sized moon.

  “That's its core,” he said. “All that's left of a planet twelve times the mass of Jupiter. It belongs to the feathery folk. Too bad there's no way to get it back to them.”

  Maybury had found something in the figures that interested her. She was making side calculations on a lightpad.

  “They were astronauts,” Jameson went on. “They made me understand that with pantomime. They were out quite a distance from their world, exploring asteroids, when the Cygnans scooped them up. They've got space flight, the same as we do. But their race doesn't have star travel yet. They were as excited by the Cygnan broomstick as Mike was. They want to go home.” He paused. “But they don't have a home to go back to, do they?”

  She made a brave effort to smile. “Is that what you came here to ask me?”

  “Yes.”

  “The third component of 61 Cygni couldn't have been their home, you know. It's an unkindled star. Nothing could have lived there except creatures like the Jovians.”

  “I know that. But I thought their home planet might have been a satellite of the superjovian—same as the Cygnans’ was. It was big enough to have planets. Big enough, even, to have an Earth-size planet.”

  “No,” she said flatly. “That would put their planet too far away from either primary to be warmed by them. It's not at all the same situation as Cygnus X-1 and its supergiant companion. Those were two hot stars with a joint ecosphere, so close together that they circled one another in only four and a half days.”

  “And 61 Cygni is a different story?”

  She almost laughed. “Commander, the two stars of 61 Cygni have a period of seven hundred and twenty days! They're far apart! They're too far apart to have a joint ecosphere. And they're both so dim that no matter which one of them the humanoids’ home world orbited, it would have to be very, very close to its star. When the Cygnans made off with the superjovian component of the system, it couldn't possibly have dragged the humanoids’ planet along with it.”

  “So their world is still there?” he said.

  “Yes,” she said. “It's still there.”

  “Thanks,” he said. He squeezed her shoulder and got up to go.

  She stopped him at the door. “Commander Jameson...”

  He turned. “Yes?”

  “Dr. Ruiz ... I mean ... what do you think will happen to his body? They won't just ... just throw it away, will they?”

  “No,” Jameson lied. “They'll probably allow the humans to bury it in their compound. It's a closed ecology. Relatively closed, anyway.”

  “That's good, then,” she said slowly. “He'll be a part of them forever now, won't he?”

  “Not just them,” he said, and left.

  Sue Jarowski looked round the wreckage of Jameson's cabin, appalled. The Cygnans had torn out everything movable, including the mattress on the bunk, and messed up what was left.

  “I suppose we can make it livable,” she said doubtfully. “I'll bring my own mattress and some cushions from the lounge.” She stared sadly at the empty shelves. “They even took your omnisound and music cards.”

  “We can live without music,” Jameson said. “I was getting tired of that damned collection anyway.”

  She gave him a probing look. After a moment she said, “Tod, don't feel bad about Maggie. She isn't worth it. She tried to get me to send a coded laser message back to Earth today. I refused. I think she was going to report Mike for sharing the Cygnan broomstick with the Chinese.”

  “She won't get very far with that. Not any more. Mike's going to be a hero when we get back. So are we all—Maggie and Gifford and Fiaccone included. We're all going to have to smile a lot at each other for the holocasts. The facts are going to be rearranged. Klein never murdered Ruiz. He was just another heroic crewman who died trying to save the human race. I never fought Chia's crowd. We were all in it together. They're going to have diplomatic problems enough splitting up the Jovian moons and the new terrestrial planet.”

  Later on, he showed her 61 Cygni through the port. “It's very faint,” he said. “You can just about make it out. Actually it's two stars.”

  “Nice,” she said, nestling up to him. She yawned. “Nice to know that there are a lot of little elves out there, covered with pink feathers.”

  The communicator buzzed. Jameson reached out and switched on the audio.

  “Commander,” Maybury's voice said. “Did I wake you up?”

  “No,” Jameson said.

  “I just wanted you to know that I accumulated enough observational data. Jupiter's going to miss the Earth. It's going to pass through just where Dr. Ruiz said it would.”

  “That's fine,” he said. “That's very fine. Now go get some sleep.”

  A week later they held a modest celebration in the saloon. Jupiter had crossed Earth's orbit twice, with no more effect than a few earthquakes and typhoons, and the bollixing up of the planetary tables in the Nautical Almanac. It already had passed the orbit of Saturn without incident, and was heading out of the solar system at the rate of six thousand kilometers per second, still picking up speed. It seemed to be heading for the Great Nebula in Andromeda.

  “They paid for it, you know,” Mike Berry said.

  “What?” Jameson
said. He'd been preoccupied watching the antics of the two humanoids. They seemed to like alcohol too. They couldn't tolerate the sugars in beer or wine, or the congeners in whiskey, but chilled vodka seemed to do very nicely for them, if it wasn't mucked up with vermouth or lemon peel. Right now one of them was mixing up a new batch in a cocktail shaker, while the other was breaking up the Chinese by doing a wickedly accurate imitation of Yeh's hulking walk.

  “They paid for Jupiter,” Mike said. “They took a planet the human race couldn't use and left us an Earth-size planet—conveniently sterile—and three of the four Galilean moons. Plus they traded us their own moon for Io. I'll bet the archeologists will go crazy.”

  “We didn't own Jupiter. The Jovians did,” Jameson said.

  Mike went on, oblivious. “That's five more planets in the solar system that the human race can colonize. And Jupiter's radiation belt isn't there to keep us away.”

  Jameson took a sip of his martini. Mike was only saying what had been on everybody's tongue for the last five days. As it hurtled Sunward, Jupiter had failed to hang on to its outer satellites and the two bodies the Cygnans had brought. It had managed to hang on to Io, of course, and the piece of rock known as Jupiter V.

  The core of the superjovian gas giant they had ridden into the solar system was now the size of the planet Earth. It was going to be the most valuable piece of real estate in the solar system, surpassing even Mars. It could be terraformed. They could make water out of the remnants of its hydrogen and the oxides in the rocks. It was rich in iron and heavy elements. And it was heavy enough to hold on to the atmosphere that could be squeezed out of its rocks.

  “And to top it all off,” Mike was saying, “Jupiter yanked them closer to the Sun before it let go. According to Maybury, it even looks like Ganymede will end up in an elliptical orbit that'll take it inside the orbit of Mars!”

  “You overlooked the biggest gift of all,” Jameson said. “They may have given us the stars.”

  Mike nodded vigorously, spilling his beer. “I've been going over that Cygnan broomstick with Po's boys. Do you know that it runs on water? Takes about a pint—we've tried it out with the ship's stuff. Uses the hydrogen. I don't know what it does with the oxygen! Very efficient—almost a hundred percent conversion to energy. It comes out as very energetic photons. They work like hadrons and scatter a hell of a lot of rho mesons. I think it's a scaled-down version of their star drive. If they can make it that small, it has to be simple!”

  “If the Chinese have been looking at that thing, there's going to be one great big crash research program on our side. I think you're going to be at the head of it. That's how the bureaucratic mind works. You were there first. You're magic.”

  “So are you,” Mike said. “You're the only person in the world who can talk to Cygnans.”

  “For the time being. There must be a few linguists around who have absolute pitch.”

  “It'll be you,” Mike said in a positive tone. “You and our pink feathered friends. With the three of you working on that Cygnan engineer we've got in the hamster cages, we ought to get enough clues to have a star drive inside of twenty years. Anyway, if I'm going to be project supervisor I won't take anybody but you.”

  “I accept,” Jameson said, laughing.

  Mike leaped to his feet, spilling more beer. “It'll be the stars, boy!” he declaimed dramatically. “Just think of it—the stars in our lifetime!”

  Heads turned in their direction. Mike lifted his glass and toasted the saloon in general.

  The humanoid who had been imitating Yeh came tumbling over in a series of cartwheels. Mike scratched it behind the ears. Everybody was doing that now. It was hard to keep your hands off them.

  “S-t-t-t-ars!” it chirruped in its songbird voice. “S-t-t-ars, s-t-t-ars, t-t-t-we!” The two of them already had picked up a few English and Chinese words, beginning with “no” and “stop” and “don't touch,” and you could understand them if you listened hard.

  “That's right,” Mike said, patting the silky crest. “We'll take you home first. Then we'll visit Alpha Centauri.”

  “Hold on there!” Jameson said. “Don't go off halfcocked. Alpha Centauri's only four light-years away, and 61 Cygni's eleven. If we get a starship out of this, the bureaucrats who finance it are going to want instant gratification.”

  People were starting to drift over, drinks in hand. Ears had perked up at the sound of what had become the most popular subject aboard the ship.

  “That's right,” Quentin agreed earnestly. “Baby steps first. That's been the whole history of the space program, ever since Stafford and Cernan and Young circled the moon before they let Armstrong and Aldrin land.”

  “Look,” Mike said. “It's a five-year trip to Alpha Centauri. Two of that is boosting and decelerating up to light-speed, during which you knock off another light-year, right?”

  “Yes, but—”

  “And it's a twelve-year trip to 61 Cygni. Same two years to boost and brake. In between you travel at, say, ninety-nine point ninety-nine percent of the speed of light.”

  “What about it?”

  Mike leaned back, looking smug. “So at that speed, the time dilation effect is a hundred to one, right? Subjective time for the crew is maybe two years and two weeks to Alpha Centauri compared to two years and six weeks to 61 Cygni.” He spread his hands. “So what's the big deal?”

  “You're missing the point,” Jameson said, egging him on. “Back home in the budget department, they're waiting ten years to show results from an Alpha Centauri round trip versus twenty-four years for a return from 61 Cygni.”

  “You're missing the point,” Mike said, grinning hugely. “61 Cygni's a sure thing! Nobody can criticize the maiden voyage. We know there's life there! And intelligent life at that!” He ruffled the humanoid's silky fur affectionately. “And we've got two friends to introduce us.”

  Quentin was still trying. “Yeah, but listen, Mike—”

  Mike sat up, an astonished expression on his face. “Hey, it just came to me! All distances are the same! Give or take a couple of months, anyway. We can reach any star within a hundred light-years in about three years of travel. The hell with them back home! If you want to spend five years traveling, you can have any star within three hundred light-years. Hell, make that ten years—no, twelve years...”

  He stopped and looked round at the circle of faces.

  Kay Thorwald said it for him. “We own all the stars in a thousand light-years. That's what we traded Jupiter for.”

  The celebration had grown suddenly quiet. Into the silence, Jameson said: “What's the price? Do we dismantle Saturn next?”

  “Hell no!” Mike said briskly. “The Cygnans spent six million years traveling with a first-generation technology. We'll have a second-generation technology. We'll find a better way.”

  Epilogue

  “There's our snowball,” Jameson said. “Let's see if we can nudge it into the cup.”

  Through the forward viewscreen the comet was an enormous sphere of frozen slush, fifty miles in diameter, according to the instruments. Out here in the cometary halo, far beyond the orbit of Pluto, it had no tail. According to Maybury's calculations, it grew its tail only once every two million years or so, when its elliptical orbit took it close enough to the Sun to vaporize its sherbetlike surface.

  “Right on target, Skipper,” Li said from his console in the circular control room. His English had improved a lot in ten years.

  It had taken only ten years to build the first starship. Mike had been right. The principle behind the Cygnans’ energized-photon drive was simple. The human race would have had it in another century anyway; the technical and theoretical groundwork already had been laid.

  Of course, the humans had made a lot of improvements.

  Sue lifted her head from the communications console to admire the view outside. The ten years had fine-etched her face, making it even more striking. Jameson was glad their daughter looked like her, not him.
/>   “Will that really take us all the way to 61 Cygni?” she said.

  “Sure,” said Mike Berry. “It's mostly water ice. Some methane, ammonia, carbon dioxide dissolved into it, of course, but the engine's only going to eat the hydrogen anyway. There'll even be enough of it left at the end to keep shielding us from interstellar hydrogen. We'll use any of that it picks up, too. Who needs a Jupiter? We don't have to boost as much mass as the Cygnans, and we don't have to push it as hard.”

  “We'll never run out of interstellar fuel,” Jameson said. “There's a hundred billion cometary nebulae out here beyond Pluto. All our starships'll have to do is come out and chase them down. And we can do that on a tank of water.”

  At constant one-g acceleration, it had taken less than three weeks to reach the fringes of the cometary halo and find their snowball. There would be similar swarms of unborn comets around every star, extending light-years into space and mingling with the cometary halos of their neighbors. There would always be a refueling stop. Man would never have to vandalize the planets, as the Cygnans had done.

  The two feathery humanoids chattered excitedly. They were temporarily free of their engine-room duties, and Jameson had invited them up to the control room for a look. This was a big moment for them.

  Slowly, the first human starship drifted toward the comet's frozen core. It was a mere two hundred meters long, a slender needle with a hundred-meter cup at one end, so that it resembled nothing so much as a gigantic golf tee.

  “Contact!” Jameson said.

  The snowball settled into the cup, or the ship landed head first on the comet, depending on how you wanted to look at it. The important thing was that the tail of the ship was pointed in the right direction. Before they'd gone very far, the ship would be half buried.

  By the time they got ready for turnaround, the snowball would be down to a more manageable size. The ship would be somewhere in the center of the comet by then, firing its photons through a tunnel melted through miles of snow. All that mass around it would be more than adequate to shield it from the diminishing hail of impinging radiation, and the drive beam itself would handily ward off the interstellar hydrogen directly ahead.