The Ring of Charon the-1

by Roger MacBride Allen

  Sondra walked back across the room and sat down next to the older woman. “The problem, Dr. Webling, is that we’re stuck with a real-life question that’s even more ridiculous—how do you make a planet disappear? Answer me that and I won’t bother you anymore.”

  CHAPTER NINE

  The Fall of Lucifer

  The Observer felt good.

  After all the endless years of waiting, it was doing what it had been created to do. Indeed, now it was entitled to a grander name than Observer. Now the work had begun, and it was a true Caller.

  Caller.

  The new name felt good, too.

  A rush of pride swept through its massive form. But proud moment or not, the effort of Calling, and Linking, was not without danger, not without strain. Though the new-named Caller was drawing massive amounts of power through the Link, the mere act of establishing that Link had drawn down its own energy reserves. The power required to create the necessary massless gravity source had left it with just a few percent of its rated power remaining. Furthermore, the quakes were desperately uncomfortable, even painful. They could be stopped only if the old gravitational balance was restored. Massless gravity fields were inherently unstable. The Caller needed an anchor, a true gravity source to stabilize the Link at this end.

  Help should come, must come through the Link. There ought to be a reasonable number of its relations surviving in the outskirts of this system, and they would assist as much as they could, but the Caller knew that the chances of success were far greater if help—and reinforcements— came through the Link.

  First and foremost, it needed a true gravity source whose power it could tap. If that did not come, all was a failure. It would have surrendered its life planet for all time, and to no avail. Failure now would condemn the Caller to a slow, mournful death, trapped and powerless, watching its power reserves trickle away to nothing.

  Help must come, the Caller told itself.

  And then it did.

  * * *

  IMPACT ALERT IMPACT ALERT IMPACT ALERT IMPACT

  Vespasian nearly leapt out of his skin, then reached over and shut off the alarm. Jesus Christ, not another one.

  Considering the crowded conditions of near-Earth space, there had not been all that many collisions so far. But each collision was a catastrophe.

  Who the hell was going to hit now? The data snapped onto his screen. Oh, no. God no. Not again.

  Lucifer. The formerly Earth-orbiting asteroid Lucifer was going to pile it in again. Lucifer had smashed into the High Dublin Habitat a few hours before. There had to be thousands dead there, and not a prayer of survivors. On any other day, it would have been the most horrifying of disasters. On the day when Earth died, it was merely a sideshow. The debris of station and asteroid were spiraling through space, causing dozens of secondary impacts.

  Even after the Dublin crash, Lucifer remained the most serious threat to the Moon and the orbiting habitats. Tamed by its human masters and towed into a stable path around the Earth over a century before, now it was free again, careering through space in a random orbit, threatening other habitats. So what was Lucifer going to clobber now?

  The computer drew the schematic for him, and the color drained from Vespasian’s face as if he had seen a ghost.

  And in a way, he had. The computers were projecting Lucifer to impact with Earth. The blue-and-white graphic image of the lost planet gleamed in the flatscreen, Lucifer’s impact trajectory shown as spiraling in. No one had had time to reprogram this particular impact warning system to tell it that Earth was gone. The computer was warning that Lucifer would strike Earth—if Earth were still there.

  If only it could be so, Vespasian thought. He’d settle for an asteroid strike on Earth if it meant getting the planet back again. He reached up a finger to dump the warning and then stopped.

  Vespasian frowned. This particular impact-warning program was a trend-projection system for constant-boost systems. It assumed that all accelerations would continue, and projected forward in time under that assumption. This program did not assume Earth’s gravity, or any other gravity field, as a constant. It merely watched radar tracks, calculated the forces preventing the track from moving on a straight line, and assumed those forces would continue.

  So why hadn’t it called this impact a long time ago? It should have been able to call it long before now, if Lucifer’s orbit had remained unchanged.

  Vespasian had checked Lucifer’s track an hour ago. Granted, they didn’t have a precise path for the rock yet, but it hadn’t been moving anywhere near Earth’s old location at that time. Now what the hell was happening? He called up a backtrack on Lucifer, running its recent actual trajectory from the tracking system.

  Sonnuvabitch. The thing had taken a hard left turn, toward Earth’s old coordinates. But that was impossible. He checked the trajectory more carefully, examining not only direction of travel, but velocity.

  The frigging thing was accelerating rapidly toward where Earth should have been. No, accelerating wasn’t quite right. That was active, and this was passive. No rockets on that rock. It was being accelerated by an outside force. It was acting like a falling body, moving toward a gravity source that was pulling it in.

  Vespasian punched up the Earth-track camera, and had his wild hopes dashed. Earth was not there.

  Vespasian leaned back, tried to think.

  And got slammed out of his chair as the Moon’s surface shuddered with new violence.

  * * *

  The second series of quakes was every bit as powerful as the first, and did every bit as much damage. It seemed as if every structure weakened in the first jolt collapsed altogether in the second. New explosions of shattered glass, new fires were everywhere. Somehow, all the SubBubbles rode out the second-wave shocks without breaching. Most people knew enough to expect aftershocks, and so the later temblors at least lost the element of surprise.

  Besides, the Lunar population was preoccupied with the far more terrifying loss of Earth. By now, hours after the event, the truth was starting to filter through and be believed. With the homeworld gone, they had little capacity for being frightened by a mere tremor.

  The second set of quakes could not have been timed more precisely to foul up Lucian’s work. He had just begun to get a handle on the orbital tracking problem when Orbital Traffic Control lost power. The emergency battery power system was supposed to be able to run the whole traffic control complex during an outage. But it had been strained by the first quakes’ outages already, and was showing signs of decay. The power-management program cut in immediately and went into conservation mode, cutting off all nonessential uses of electricity.

  Unfortunately, hypothetical modeling of speculative orbital projections went under the heading of nonessential use as far as the automatic power-management software was concerned. Lucian’s panel went dead and stayed dead. He couldn’t even program an override of the power-management system until his board came on.

  All across cis-Lunar space, spacecraft and stationary facilities alike were out of control, tumbling through space in unpredictable directions.

  Through all the long years and centuries since the first manned stations were put up, whenever a new facility was placed in an orbit of the crowded Earth-Moon system, computers and engineers would labor long and hard to place it in a safe path, to keep it away from all the thousands of other orbiting craft and stations.

  But all that fastidious timing and positioning had been overturned when Earth was suddenly not there to hold the reins. In the careful dance of the orbits, it had been Earth that had called the tune—and now the caller was gone, leaving the dancers themselves to wheel and pitch about at random.

  Lucian was trying to find out just how bad the situation was—a tricky job with a dead computer. He sat there, staring at the blank screen, trying to think.

  He had gotten far enough along in the problem to confirm his original fear. Earth’s disappearance was no illusion. Working by hand, he had recalcul
ated projected orbital trajectories for several of the larger habitats, factoring Earth’s disappearance into the existing projection as stored in the navigational almanac system. He had fed his coordinates to the radar controllers, and radar had reported dead-on tracks for every habitat.

  And the message was simple: without the Earth to anchor them, the Earth orbiters were careering across the sky. The Moon-orbiting satellites were not in much better shape—Earth’s massive gravity well was a major variable in their orbits as well. Several satellites and habitats had already spiraled down to impacts on the Moon, including all of the satellites stationed at the Lagrangian balance points. Held in stationary orbit over the Lunar Nearside and Farside by the balance of terrestrial and Lunar gravity, some of the Lagrangian stations had drifted off into deep space, and others had simply fallen down, once Earth’s gravity was no longer there to hold them up.

  Other facilities hadn’t crashed yet—but they would, their impact points as inevitable and irrevocable as gravity itself. They were falling now, and nothing could stop them. The few stationary facilities with powerful station-keeping engines might be able to save themselves. But most of the stations had no stationkeeping engines, or only small ones. There was no way to correct their courses, even if Lucian had been able to calculate their present courses in time.

  All of the objects Lucian tracked were still held in orbit about the Sun, of course, but the speed and vector each held at the moment Earth vanished threw a random element into the mix. Some were moving into higher-inclination orbits, others in a bit closer to or out a bit further from the Sun.

  But what frightened Lucian most of all was that it should have been worse. Many of the predicted disasters never happened. Radar couldn’t spot many of the threatened ships in the first place. According to the computer plots, there should have been far more impacts, more collisions, more spacecraft radioing in to report themselves off course. Satellites, habitats and spacecraft, lots of them, were simply missing.

  Suddenly, with a flare of lights and a renewed hum of ventilation fans, the primary power system came back on. Lucian’s console flashed into life. He leaned into the keyboard and ran some quick checks. Yes, his programs were still intact. That much was a relief. But what about the missing satellites? Lucian ordered up a three-dee projection of the coordinates for the missing ships and stations, as of the moment before Earth disappeared.

  The pattern in the three-dee tank was clear, obvious, and clean. It was not merely the Earth that was gone, but everything that had been within a certain volume of space surrounding Earth. Somehow, that made it seem real. It was easier to conceive of a space station ceasing to exist than a whole planet. It was suddenly real enough to be frightening.

  The intercom bleeped and Lucian punched the answer button. It was Janie in Radar, paging him on the intercom. “Lucian, you got a second?”

  Lucian looked over and spotted Janie on the far side of the big room, saw her looking not at him, but at her display system. It was disconcerting to speak to disembodied voices all day, when you could see the bodies they belonged to, out of earshot. Lucian adjusted his earpiece and spoke into his throat mike. “I’ve got just about that long, Janie. What’s up?”

  “I’ll relay it to your screen. It’s kind of hard to explain. You had me do a radar track on Mendar-4, right?”

  “Right,” Lucian said.

  “Okay,” Janie’s voice said. “Here’s what’s what. This is what Mendar’s orbit was.” A standard orbital schematic appeared on Lucian’s flatscreen. Earth stood in the center of the screen, and Mendar-4’s track showed as a perfect white circle tracing around it. “Now this is an orbit based on the radar tracks we’ve gotten since the first quake.” The symbol for Earth vanished from the screen, and Mendar moved straight out on a tangent from its previous orbit. “I’m running it forward in blue to give us a projected orbit.”

  Lucian watched as the straight blue line stretched out into Solar space.“Okay, so what?” Lucian asked.

  “So here’s what happened after the second quake, just a few minutes ago. This is Mendar’s actual course, based on radar tracking. I’ll run it in yellow.” A third course appeared on the screen, peeling away from the straight blue line of the projected course.

  “Holy Jesus Christ,” Lucian said.

  He knew what it meant, even without analyzing the orbit. Mendar’s path was being bent back toward some large mass, a large mass right where Earth had been. A planet-sized mass.

  “Has this happened to the other orbital tracks?” Lucian asked, his fingers busy running his own board. He could feel the relief washing over him. It had to be. Earth was back from whatever impossible place it had been. It had to be.

  “Yes it has,” Janie said. “Similar orbit shifts, all starting just at the onset of the last quake.”

  “It’s got to mean that Earth is back,” he said, excitedly. “That’s what caused the second quake series. Earth’s gravity field coming back and grabbing at the Moon.” He brought up the image from the surface camera, still trained on Earth’s coordinates.

  But there was nothing there. Nothing at all. Just some debris.

  “I checked that too, first thing, Lucian.” Janie’s voice was soft, apologetic. “There’s nothing there.”

  “Give me a real-time radar image of where Earth should be,” Lucian said. Maybe it was simply cloaked somehow, some weird optical phenomenon. Janie redirected her radar and Lucian split his screen, watching the same swatch of sky in visual and radar frequencies.

  “Nothing, Lucian,” Janie said. “Not one damn thing—”

  Suddenly there was a blue-white flash of light in the center of the visual screen, and a smaller, dimmer flicker on the radar. And then, on radar, a target appeared. A big one, Lucian judged. Perhaps two kilometers across, and moving fast. About the size of the other debris chunks in the radar image. And all the debris was moving away from the new gravity source. Almost as if they had been launched themselves…

  “You got a recording on this?” Lucian asked.

  “Sure thing,” Janie said.

  “Let me access that. Last fifteen minutes of it.” Lucian cut away from the live picture and ran the recording forward from the moment the quakes hit.

  Another flash, and another target. And again, and again, and again. Some of them drove straight on. Others seemed to snap around in tight parabolas before speeding away. They had to be moving at a helluva clip for the motion to be visible at this range, even in fast forward. Larry ran a check, and discovered that the targets were popping out of the bluish flashes at regular intervals, once every 128 seconds.

  The image reminded him of something, and it took a moment for it to register. Like lifeboats launching from a crippled ship, Lucian thought. For one wild moment he wondered if that was exactly what he was seeing—the populace of Earth somehow escaping from their wrecked planet.

  But in ships two klicks across? No one built them that large. The whole idea was absurd.

  But then, so was the idea of asteroid-sized bodies materializing out of the empty spot in space where Earth had so recently been.

  Lucian stared at his screens, praying for understanding. It didn’t come.

  * * *

  The Caller saw the intruder diving toward its Anchor. This was by no means a surprising development. Of course the Anchor’s massive gravity well would attract debris. The Caller immediately sent a message through the Link, requesting a temporary halt to operations. Nothing material could ever damage the Anchor itself, of course, but a disintegrating asteroid could certainly damage the new arrivals as they streaked through the worm-hole. It did not matter. Now the Caller had the Anchor as a power source. Now it had all the time and power it could ever need—and this asteroid would be out of the way in a few minutes.

  * * *

  Lucian, still staring at the mysterious blue flashes, was startled to see them stop coming, and startled again to see an asteroid-sized fragment moving in toward Earth’s previous position
. The new radar track had an ID tag on. This one, the computer could identify. Lucifer. Sweet Lord, Lucifer.

  Lucian jumped up, unplugged his headset, and hurried over to Vespasian‘ console. “Vespy, are you watching the Lucifer track?” he asked.

  “I’m on it, Luce.”

  Tyrone Vespasian glanced away from his console and rubbed his jaw nervously. Lucian stood behind him, watching in silence as the radar tracked the wreckage of Lucifer tumbling through space, pitching and wheeling wildly. The huge worldlet was tumbling, out of control. What was happening? Earth wasn’t there. But Lucifer was falling toward something. And falling fast. Vespasian checked the real-time track.

  Hell’s bells. It was moving toward that gravity source at ten klicks a second, and accelerating. He asked the computer for an impact projection. Twenty minutes. That was too fast a fall. Tyrone Vespasian had been running orbital traffic systems for a long time. He knew the space around Earth and the Moon intimately, almost by feel. He knew, instinctively, what sort of forces Earth and the Moon would impose on a body in a given position. And Lucifer’s acceleration was wrong, just a shade high.

  With Lucifer’s acceleration toward this gravity known, it was dead-simple to measure the mass of the gravity source—or, at least, the total mass of the gravity source plus Lucifer, and subtract Lucifer’s listed mass. Probably it had lost some fragments after Dublin, but the result would be close enough.

  Result of calculation: 1.053 Earth masses. It couldn’t be Earth. Not unless the planet had gained a few gigatons in the last few hours. Besides, this gee source was invisible.

  Holy Christ. Invisible gravity source. Vespasian suddenly realized what was out there. But he couldn’t believe it. He wouldn’t believe it.

  He checked the impact projection clock. He wouldn’t have to believe it for another eighteen minutes. He powered up the maximum-gain telescopic camera and trained it on the dot of light that was Lucifer. The camera zoomed in, the electronic amplifiers came on, and the typical rough potato-shape of an asteroid was tumbling in the center of the screen, tracking and velocity information appearing in a data window in the lower-right corner of the screen. Vespasian watched the fall of Lucifer, willing himself not to believe the evidence of his own eyes.