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 recalculated 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.