Searcher: GOOD FIND ROCK. IF YOU'RE RIGHT, THAT MEANS THE RAMSCOOP WAS DESIGNED TO PICK UP LESS THAN A KILOGRAM PER SECOND OF HYDROGEN IN INTERSTELLAR SPACE. A FULL PAYLOAD OF DEUTERIUM WILL DEFINITELY BE MORE ENERGY RELEASE, PROBABLY IN JUST MICROSECONDS, THAN IT WAS DESIGNED TO PROCESS.
Violet: FOLKS, THE FUEL HAS TO BE IONIZED. THE RAMSCOOP IS PROBABLY EITHER ELECTROSTATIC OR SOME COMBINATION OF ELECTROSTATIC AND MAGNETIC FIELDS. IT WON'T INTERACT WITH NEUTRALS, AND AT THAT SPEED, IT PROBABLY CAN'T PROJECT ANYTHING AHEAD OF ITSELF TO IONIZE NEUTRALS. BUT I'M COMING HOME WITH A NEARLY FULL LOAD OF DEUTERIUM.
Rockhound: I'VE GOT ABOUT HALF A LOAD.
Iceman: RENDEZVOUS HAS ABOUT 6,000 TONS STOCKPILED, WAITING FOR THE NEXT TANKER TO PICK IT UP. NO WAY TO CHANGE LOCATIONS, THOUGH. I'M TRANSMITTING THIS WHOLE EXCHANGE TO EARTH, BUT THERE ISN'T TIME TO WAIT FOR A REPLY. MAYBE THEY CAN MOUNT SOME KIND OF LAST-DITCH DEFENSE WITH IT. I HOPE THEY FIGURE OUT THE SAME THING, OR SOMETHING BETTER, BECAUSE THAT WOULD GIVE THEM ANOTHER THREE DAYS TO PREPARE.
Searcher: VIOLET, IF THIS THING GETS PAST US, EVERYBODY IN THE INNER SYSTEM WILL PROBABLY DIE. YOU MAY BE THE ONLY WOMAN LEFT. DON'T DO ANYTHING RASH, OKAY?
Violet: YOU GUYS KNOW I LOVE TO FLIRT AND I LOVE ALL THE ATTENTION, BUT MAYBE, BECAUSE I'M THE ONLY WOMAN WITHIN 300 AU OF HERE AND YOU HAVEN'T SEEN ANOTHER ONE IN A WHILE, YOU FORGET I'M OVER 80 YEARS OLD. FOR ME TO BE ANOTHER EVE WOULD TAKE A TEAM OF MEDICAL SPECIALISTS THAT ARE ALL GOING TO COOK IF SOL BLOWS UP.
Rockhound: ANYBODY HAVE ANY IDEA WHY WE CAN'T TAKE THIS THING OUT JUST BY DUMPING A ROCK WITH A MASS OF A TON OR SO IN ITS PATH? AT THAT SPEED, I WOULD THINK IT WOULD EFFECTIVELY TURN WHATEVER IT HIT INTO ENERGY. I'VE ALWAYS HEARD THAT HITTING EVEN LITTLE STUFF AT RELATIVISTIC SPEEDS WOULD BE FATAL.
Iceman: YEAH, ROCK, IT WOULD CAUSE A HELLUVA BANG, IF YOU COULD HIT SOMETHING AS SMALL AS THE HULL, WHICH WOULD BE PRETTY DIFFICULT CONSIDERING IT WILL LOOK LIKE IT'S A LIGHT-YEAR AWAY JUST SECONDS BEFORE IT HITS YOU. BUSSARD WOULD HAVE BEEN A LOT BETTER AT THIS MATH THAN ME, BUT I THINK THERE'S SOMETHING IN GENERAL RELATIVITY THAT ACKNOWLEDGES THAT THE RAMJET HAS BEEN GORGING ON ENERGY FOR DECADES WHILE WE'VE BEEN SITTING ON OUR ASSES, AND THAT PROBABLY BIASES THE IMPACT RESULTS HEAVILY IN ITS FAVOR. I KNOW THERE'S AN ASYMMETRY LIKE THAT FOR TIME DILATION. AND THIS WON'T BE SOME PASSENGER SHIP BUILT LIKE A BIG CAN. IT WILL PROBABLY BE MORE LIKE A BATTERING RAM, TIMES GAMMA CUBED. IF I WERE DESIGNING IT, I'D GIVE IT ONE OF THOSE MULTI-LAYERED METEOR SHIELDS, PROBABLY MADE OF THICK ARMOR PLATE, GENEROUSLY SPACED APART BY A FRAMEWORK. YOU MIGHT VAPORIZE THE FIRST ONE AND DAMAGE THE SECOND, BUT THE BULK OF THE THING WOULD SURVIVE.
Rockhound: YEAH, BUT IT'S STILL MADE OF MATTER, RIGHT? WOULDN'T A 2,000-MEGATON BLAST AROUND THE HULL VAPORIZE IT?
Searcher: NEGATIVE, ROCK. THE ORION PROGRAM, THE ONE WHERE THEY WERE GOING TO TRY USING NUKES AS ROCKET FUEL, REFERENCED SOME DATA FROM A COUPLE OF BIKINI ISLAND TESTS. THEY PUT BIG STEEL SPHERES VERY NEAR THE CENTER OF THE BLAST, AND THEY WERE BARELY SCORCHED.
Iceman: YEAH, ORION! I SHOULD HAVE REMEMBERED! GUYS, I MAY HAVE BEEN PESSIMISTIC TOO SOON. THE EQUATION I GAVE YOU A FEW MINUTES AGO IS FOR FORCE REQUIRED in the direction of travel. BUT AT RIGHT ANGLES, IT'S JUST F = g.M.A. THAT'S HALF A MILLION TIMES BETTER! AND SEARCHER, LOOK UP A TEST WHERE THEY HAD A HEAVY PLUG ON TOP OF A LOW-YIELD NUKE IN ONE OF THE FIRST UNDERGROUND TESTS, AND KICKED IT TO SOMETHING LIKE SIX TIMES EARTH'S ESCAPE VELOCITY. THAT SHOULD BE IN THE ORION STUFF. IT INSPIRED THE PROJECT.
Searcher: ICE, YOU'RE RIGHT. THAT MUST BE THE PLUMBBOB PROGRAM, A SHOT CALLED PASCAL B. IF I'M READING THIS RIGHT, THE YIELD WAS ONLY ABOUT 300 TON—JUST A POP! YOU THINK WE HAVE A CHANCE TO PUSH THIS THING ASIDE? CAN WE MAKE IT TURN IF IT CAN'T TURN ITSELF?
Iceman: HARD TO SAY. PROBABLY AT LEAST PART OF THAT STEERING PROBLEM IS THE SAME REASON WE'RE GETTING SO LITTLE WARNING: IT'S “CHASING LIGHT” AND IS HAVING TROUBLE SEEING AHEAD IN TIME. IF WE COULD GIVE IT JUST 8,726 KPH TO ONE SIDE, IT WOULD JUST MISS THE SUN. IF WE SET OFF A 2,000-MEGATON EXPLOSION IN CONTACT WITH ONE SIDE OF A BIG CHUNK OF ARMOR PLATE WITH THE MASS OF A BATTLESHIP, I'D SAY IT WOULD WORK, PROBABLY BY A BIG MARGIN. BUT AGAINST 707 BATTLESHIPS? AND WE'RE JUST GUESSING AT THE MASS OF THAT THING. BUT WITH SEARCHER'S TRICK, THE SCOOP ITSELF WILL DIRECT THE DEUTERIUM RIGHT IN AROUND THE HULL AND SET IT OFF WHERE IT COUNTS. AND SINCE IT'S ALMOST A SURE BET WE'LL HIT IT OFF-CENTER, THE FORCE WILL BE OFF TO ONE SIDE. IT WILL BE DIFFICULT ENOUGH JUST TO FIGURE OUT THE TRAJECTORY, SO I'M NOT WORRIED WE'LL HIT IT DEAD CENTER. I THINK TEDDY ROOSEVELT SAID, “DO WHAT YOU CAN, WITH WHAT YOU HAVE, WHERE YOU ARE.” I THINK THAT'S WHAT WE HAVE.
Searcher: ICE, DO YOU READ HEINLEIN? “ALWAYS LISTEN TO EXPERTS. THEY'LL TELL YOU WHAT CAN'T BE DONE AND WHY. THEN DO IT.” YOU'RE RIGHT, IT WILL BE HARD TO HIT. BUT WE CAN ASSUME IT IS AIMED NEARLY DEAD CENTER OF THE SUN, PROBABLY WITHIN ONE FIFTIETH OF THE SUN'S RADIUS, AND WE KNOW IT CAN'T TURN ITSELF. EVEN IF IT HITS THE SUN BUT DOESN'T GET THAT CLOSE TO THE CORE, MAYBE THAT'S GOOD ENOUGH. AS I SEE IT, OUR BEST BET IS TO GET ON A STRAIGHT LINE BETWEEN WHERE WE SEE THAT THING NOW AND DEAD CENTER OF SOL. MOST OF US ARE PRETTY CLOSE RIGHT NOW. STINK AND CRUSTY, MAYBE YOU SHOULD START IN.
* * * *
"Computer, cabin video log on.” Victor waited for the record indicator to light up and turned toward the camera. “This is definitely worth recording for posterity. In my library is an old classic TV series, in which one of the characters says, ‘do not confuse coincidence with fate.’ A little while ago, the borebot cut this core sample and sent it up here.” He tilted up a circular disc larger than a dinner plate, with a globular surface that was missing a small patch. “Watch this."
Victor picked up the flake of asteroid he had found a decade earlier in the inner system. Gently, he matched it up with a divot missing from the disc. The fractured surfaces matched up perfectly.
Victor smiled up at the camera. “Up to now, I've been able to think that good detective work is what led me here. Good luck played a role. It did take a little luck to find this flake, but even that was mostly orbital mechanics and a systematic radar search. After all my homework, there was about a one in a hundred chance that this object would be El Dorado, but that's not enough of a coincidence to impress a poker player. But to bore right down to this huge ball of iron, expose a three-meter diameter patch of it, and find the exact spot where the flake originated? Man, that's not coincidence, that's destiny!"
He glanced at his watch. “Damn, I haven't been on the net in over a day. They probably think I'm dead! I've got enough for a solid claim, and the forms are ready to file. I wonder if it's time to let the cat out of the bag?"
* * * *
Searcher: ALL NET ALERT! EARTH JUST SENT THEIR BEST TRAJECTORY ESTIMATE. THEY'LL SEND REFINEMENTS AS FAST AS THEY COME IN. LOOKS LIKE WE'RE ALMOST ON THE LINE, JUST AS WE THOUGHT.
THEY FIGURED OUT EVERYTHING WE DID, AND MORE. THEY'VE GOT EVERY SHIP THAT CAN REACH THE TRAJECTORY MOVING OUT FOR AN INTERCEPT. THEY'RE ALSO GOING TO TRY DEUTERIUM RELEASE, BUT THEY'RE AFRAID IT WON'T WORK. THEIR ANALYSTS THINK THE RAMSCOOP WILL BE TURNED OFF SOME TIME BEFORE IT HITS THE SUN, TO BE SURE IT DOESN'T WASTE KINETIC ENERGY INTERACTING UNNECESSARILY WITH THE CORONA AND PHOTOSPHERE. MOST OF THE SHIPS ABLE TO MAKE AN INTERCEPT ARE WITHIN ABOUT FOUR AU OF THE SUN. THAT'S ABOUT HALF A LIGHT-HOUR. IN RAMJET TIME, THAT WOULD BE MORE LIKE TWO AND A HALF SECONDS, SO THERE IS A GOOD CHANCE IT WILL BE SWITCHED OFF BY THEN. AND IF WE CAN FIGURE OUT THE DEUTERIUM TRICK ON SHORT NOTICE, THE DESIGNERS COULD TOO, AND THEY WOULD SWITCH THE THING OFF BEFORE THEY THOUGHT THERE WAS A SERIOUS THREAT. THE BET IS THAT IT WON'T WORK.
SO THEIR MAIN STRATEGY IS TO GET EVERY SOLID OBJECT THEY CAN INTO THE PATH OF THAT THING, GIVE OR TAKE THE PROJECTED UNCERTAINTY. THEY'RE GOING TO MAKE IT RUN THE GAUNTLET, AND MAXIMIZE THE CHANCES FOR A DIRECT HIT. BUT THE TRAJECTORY IS WAY ABOVE THE ECLIPTIC. IT ISN'T COMING IN THROUGH THE KUIPER BELT AND ASTEROID BELT, AND THERE ARE NOT MANY HEAVY OBJECTS THEY COULD EVEN HOPE TO MOVE INTO ITS PATH, AND ONLY THREE BIG MASS DRIVERS ANYWHERE CLOSE. BASICALLY, THEY DON'T STAND A SNOWBALL'S CHANCE IN
HELL OF GETTING A 200-KILOMETER ASTEROID INTO THE PATH OF THAT THING.
SO THEY ARE DOING IT WITH SHIPS. THEY'VE GOT HUNDREDS OF THEM CONVERGING ON THE TRAJECTORY. THEY ARE EVEN INSTRUCTING THE SHIPS TO TURN BROADSIDE TO IT. THE ODDS OF A DIRECT HIT ARE STILL NOT GOOD. THE TROUBLE IS, ALL THIS IS TOO CLOSE IN. IF THEY MANAGED TO GET A SMALL ASTEROID IN ITS PATH, IT MIGHT MEAN THEY TURN A RIFLE SHOT AT POINT BLANK RANGE INTO A SHOTGUN BLAST AT POINT BLANK RANGE. SAME OUTCOME. BUT THAT THING WILL PROBABLY GO THROUGH A FREIGHTER LIKE A BULLET THROUGH TISSUE PAPER.
FRIENDS, THERE IS NOTHING BETWEEN US AND THEM. WE MAY BE FAR ENOUGH OUT TO KILL IT IN TIME. THERE'S A MUCH BETTER CHANCE THE RAMSCOOP WILL STILL BE TURNED ON OUT HERE, AS THEY GO FOR A LAST BURST OF ENERGY IN THE SLIGHTLY DENSER GAS AS THEY COME OUT OF INTERSTELLAR SPACE. THEY PROBABLY DON'T EXPECT WE WOULD HAVE ANYONE IN POSITION THIS FAR OUT. IT'S THE MOST FANTASTIC SHEER DUMB LUCK WE are HERE. AND IF WE CAN MANAGE TO BLAST THAT THING SIDEWAYS, MAYBE THEY'LL HAVE A CHANCE.
* * * *
Victor reviewed the backlog of forum messages in shock. He finally regained his senses enough to begin processing the bad news. In the time he had been ignoring them, the news had gone from discovery of an almost comical rant from too far away to matter, to a serious doomsday threat. He glanced at the ship status display.
"I wonder if those jackasses are trying to punk me? Aretoo, get your sorry mechanical behind in gear and go dust the snow off the telescope dome."
"Command not valid,” the robot panel complained.
"Aretoo, remove foreign material from telescope dome."
"Command accepted,” the panel declared, and the display showed a maintenance robot scurrying down the trunk rail toward the telescopes.
Victor opened a data file attached to one of Searcher's posts, and transmitted the spherical coordinates to the gamma ray telescope. The coordinates would be easily in view at this point in El Dorado's rotation. A minute later, the robot reported the task was completed. Victor opened the dome and activated the telescope. The image quickly began integrating, and resolved a steady, bright pinpoint of hard gammas just where the incoming object should be. There was enough signal for a decent spectrum.
"I thought they said this thing was barely detectable. This scope is not that much better than the others. If those top peaks are supposed to be positron annihilation gammas, what's the blueshift? Um, works out to about 0.02, which would be 0.9992c. Could they be faking this? I don't see how. Jeez, they must be right, that thing is screaming in, way faster than it looked just a few hours ago.
"Computer, connect the spectra from the IR, visible, and UV scopes with the x-ray/gamma spectrum, and correct for blueshift of 0.02.” Victor studied the display. “Interesting. That doesn't look like it's all heat. Computer, model and remove blackbody spectrum. Uh-huh, and there's a cutoff at the upper end. Reminds me of the electron-cyclotron resonance spectrum in a magnetic grid corner cusp, actually. This is way too sophisticated for those guys to fake. But what kind of field would cause ECR at a nanometer? Damn, it would take around ten million teslas. That's only an order of magnitude short of the polar field of a neutron star! So, you monster, you do use a magnetic field for at least part of your ramscoop operation.
"What the hell would something like that be made of, anyway? A nickel-iron structure would be crushed by a field that strong. In fact, it's more than a million times stronger than a field that would levitate diamagnetic materials, so it would probably tear carbon fiber to shreds.
"How fast would something like this expand? It would only be seven hours behind the light it emitted a light-year out! And if it's doing six nines of light ... that drops to half a minute! It will blossom from a pinpoint to as big as the moon in a heartbeat, as if it were coming in faster than light!
"So next, I suppose I'm expected to push off from here and go out and take up position to try and stop that damned thing. Screw that shit! Nobody has said it, exactly, but I'd say it is a safe bet what they're talking about would be fatal. The odds are I won't be close enough anyway. Nobody else out here has as much to lose as I do. Let one of those other poor bastards do it, since they're all so eager to die."
Another updated trajectory came in. The estimated error cone was tighter now, definitely centered west of the station. El Dorado was near the center.
"Shit, what are the odds that thing is gonna hit my pot of gold?” He ran the calculation. “Slim. Close to zero, in fact. It'll probably pass about a hundred thousand klicks east of here. Odds are better I can use it to shield me when that thing goes by. Damn, that's a lot of gamma rays! And Ice was right: Even if I wanted to push this thing into the most probable path, no way do I have enough impulse, not by a factor of a thousand at least, so they can't blame me for not trying."
Victor paused to think. “They can't blame me for not trying to push El Dorado. They'd blame me for not getting out there to try to stop this thing. My tanks are chock full of high-grade fusion fuel, and the best projection is just a few hours east of me. So if I just let this thing go by and do nothing, and Earth gets cooked, and then I come in and file a claim on El Dorado, they'll know I was right there and just watched it go by. Man, if I think I'm short on friends now, imagine afterwards."
A motor down in the bowels of the ship growled as the borebot was raised back into its bay.
"Says you!” Victor glowered at nothing in particular. “You forget, my tin friend, that if we try to stop that thing, you fry with me. So let's not even go there. The fact is, I'll be so rich, those toads will be kissing my ass anyway."
Victor froze. “Or ... wait. Shit, my whole damned business model is screwed to hell! If the inner system is destroyed, what do I do for a customer base?” He paused to think again.
A nasty smile formed on his face. “But I'd still be sitting on top of the richest find the Oort Cloud has ever produced. There are what, four exploration outposts out here, plus that deep exploration ship, Nemesis, out about a quarter light-year on the ecliptic? The inverse square law is the best shielding, so they say. The other outposts will probably get thru this without a scratch, and that ship certainly will. So humanity will survive. We'll just start over out here. It will take a few generations before it means much, but I'll still be the richest man in the system. And if I have a chance of stopping that thing, it looks like at least three other ships have about the same chance. Maybe Earth won't be destroyed after all. I'll pay for a really nice statue in honor of whoever intercepts it."
"Aaargh! There aren't many medical doctors out here! I wonder how long it would take us to re-create the life extension technology they have in-system?"
The last forum exchange with Violet crossed his mind. “Hell, there's another hole in my plan. I don't even know if there are any women of childbearing age out in the Cloud at all. Because of the radiation hazards, most women with the itch to come out and explore wait until those days are behind them."
A valve deep in the ship hissed loudly, venting gas in preparation for decoupling the borebot's umbilical.
"Yeah?” Victor replied, “So what if I am a piece of shit? Now shut up and get back to work."
* * * *
Searcher: I GUESS YOU GUYS ARE WATCHING THESE TRAJECTORY UPDATES. THEY ARE RAPIDLY CONVERGING WEST OF RENDEZVOUS. ALL OF THIS INFORMATION FROM EARTH IS OLD NEWS. WE'LL PROBABLY BE TOO FAR BEHIND IF WE DEPEND ON THEM MUCH LONGER. AT THIS POINT, I'D SAY WE HAVE TO TREAT THIS LIKE ANY OTHER VISUAL INTERCEPTION, JUST WITH REALLY BIZARRE VELOCITIES. THAT THING IS GOING TO SUDDENLY START LOOMING LARGE, PROBABLY IN A FEW HOURS, AND WHEN IT HAPPENS, IT WILL BARELY BE POSSIBLE TO REACT. WHEN YOUR TARGET IS NOT MOVING RELATIVE TO YOUR FIELD OF VIEW, ONLY BLOSSOMING IN YOUR VIEW SCREEN, YOU'RE ON AN INTERCEPT COURSE. TRY TO STAY CENTERED ON IT THE BEST YOU CAN. PETE, CRUSTY, IT LOOKS LIKE YOU GUYS ARE OFF THE HOOK. YOU CAN'T POSSIBLY GET HERE IN TIME. ICE, DOESN'T LOOK LIKE RENDEZVOUS WILL BE IN PLAY, EITHER. HAS ANYBODY HEARD FROM WIENER? THAT THING WILL PROBABLY PASS WEST OF THAT LITTLE ICE BALL HE'S EXPLORING, AND HE PROBABLY COULD GET THERE IN
TIME. HE SHOULD HAVE FULL TANKS BY NOW.
* * * *
Victor stared at the core sample disk. Hatred burned in his eyes. The latest trajectory update was still on his screen, with the estimate of the launch date, the same year Victor had been born.
"It's not fair. You stupid chunk of inanimate matter, you suckered me out here, didn't you? Both of you. You and my flaky little buddy sitting in that divot. Man, I should have lashed myself to a mast and not let you two sirens seduce me. But that wouldn't have helped, would it? I'd probably be back in the belt and I'd fry with everyone else. So it's my fault. I should have picked Rendezvous 2 instead of Rendezvous 3. But then I'd never find El Dorado, and I'd just be a poor, lonely ice miner, living out my years out in the dark and cold and wishing there were some women around."
Victor continued to stare at the disk, as the wheels ground furiously in his mind.
"How the hell did you get out here, you stupid ball of iron? Did God do it? Could some all-powerful, all-knowing son of a bitch have foreseen all this? I mean, this all started over four billion years ago. Life on Earth—and the other world too, I suppose—couldn't have been more than slime in mud puddles, if it even existed then! How could anyone, even an omniscient being, know this would happen, now, here? Even if God is a magnificent billiards player, how could He possibly predict the future, when creatures with free will are involved?"
He placed his head in his hands, sobbing. “What's the matter with your aim, God? Did you miss? Is that it? Yeah, admit it. You were off a tiny hundred thousand kilometers after the billiards shot of all time! So you lure me out here to fix the problem, is that it?"
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