“Yes; judging from the vector, it was on the other side of Kali. Grid Reference L4.”
“Wake up, Colin—we must go and have a look. Must be a meteor strike—”
“Lasting ten seconds?”
“Um. Oh, hello, Colin. Did you hear all that?”
“Yes—most of it.”
“Any theories?”
“Obviously the Reborn fanatics have landed, and are trying to undo our good work. But their drive’s in bad need of a tuneup, by the look of that curve.”
“Ingenious—but I think we’d have seen them coming. Meet you in the airlock.”
Since Sir Colin Draker’s birthday party, there had been little occasion to go far from the ship; all activity had been concentrated in an area only a few hundred meters across. As the sled carried Singh, Draker, and Fletcher around to the nightside, the geologist remarked to his companions: “I can make a pretty good guess—would have thought of it earlier if there hadn’t been so many distractions…. My God! Do you see what I see?”
Spanning the sky ahead of them was something Robert Singh had not seen since he left Earth decades ago—and under no circumstances could exist on Kali. It was, unbelievably but unquestionably, a rainbow.
Fletcher almost lost control of the sled as he stared up into the impossible sky. Then he brought the vehicle to a halt, and it began to settle slowly to the ground.
The rainbow was fading fast; by the time the sled had hit Kali, with the impact of a falling snowflake, it had vanished completely.
Sir Colin was the first to break the awed silence.
“‘Then God said: I have set my rainbow in the clouds, and it will be the sign of the covenant between me and the Earth…. Never again will the waters become a flood to destroy all life.’ Strange that I should have remembered that—I’ve not looked at the Old Christian Bible since I was a boy. I only hope it’s good news for us, as it was for Noah.”
“But how could it happen—here?”
“Drive on slowly, Torin, and I’ll show you. Kali’s waking up.”
37
STROMBOLI
GEOLOGISTS—UNLIKE PHYSICISTS AND ASTRONOMERS—SELdom became famous, at least in the line of duty. Sir Colin Draker had never wished to be a celebrity, but that was a fate no one aboard Goliath could now escape.
He was not complaining; he felt he had the best of both worlds. No one could pester him with requests he could not fulfill, engagements he did not wish to accept. But he did enjoy giving his regular commentary (“Colin on Kali” as it was universally nicknamed) over the Inner System Network. This time he had some real news to report.
“Kali is no longer an inert mass of metal, rock, and ice. It is awakening from its long sleep.
“Most asteroids are dead—totally inactive bodies. But some are the remains of ancient comets, and when they approach the sun, they remember their past….
“Here is the most famous of all living comets, Halley. This image was made in 2100, when it was at its greatest distance from the sun, just beyond the orbit of Pluto. As you’ll see, it looks very much like Kali—just an irregular mass of rock.
“As you probably know, we have now followed it around the sun for the whole of its seventy-six-year orbit, watching the changes it undergoes. Here it is passing the orbit of Mars—what a difference, now that it’s heating up after its long winter! The frozen ices—water, carbon dioxide, a whole mixture of hydrocarbons—have begun to vaporize, and have broken through the crust. It’s starting to spout like a whale….
“Now they’ve formed a cloud all around it—the camera is pulling back—see how the tail is forming, pointing away from the sun like a wind vane in the solar gale….
“Some of you will remember how spectacular Halley was in 2061. But since it’s been evaporating like this for ages—just imagine what it must have been like when it was young! It dominated the sky before the Battle of Hastings, 1066—and even then it must have been only a ghost of its former glory.
“Perhaps Kali was equally spectacular, thousands of years ago, when it was a real comet. Now all—well, almost all—the volatiles have been boiled off during its passage close to the sun. This is the only sign of its past activity that remains today….”
Rather jerkily, the hand-held camera on the space-sled panned across the face of Kali, from a height of only a few meters. What had recently been a cratered, charcoal-black terrain was now flecked with patches of white, as if there had been a recent snowfall. They were concentrated around a gaping hole in the surface of the asteroid, over which a barely visible mist was hovering.
“This was taken just before local sunset. Kali has been heating up all day—now she’s ready to blow—watch!
“Just like a geyser on Earth, if you’ve ever seen one. But notice that nothing comes down again—it all shoots off into space: gravity here is much too feeble to recapture it.
“And it’s all over in thirty seconds, though the outbursts may last longer and become more powerful as Kali gets closer to the sun.
“You might say we have our very own mini-volcano—solar powered! We’ve decided to call it Stromboli. But the material it vents is quite cold—if you put your hand in it, you’d be frostbitten, not burned. Probably this is Kali’s last gasp; next time around the sun, it will be completely dead.”
Sir Colin hesitated for a moment before signing off. He had been tempted to add: “If there is another time around the sun.” It would be weeks before he could be sure if there was any basis to his fears, and it would be foolish—no, criminal—to raise unnecessary alarm while the world continued to relax.
Although Kali was still in the public eye, it was no longer as a symbol of doom, but as Exhibit One in “Trial of the Century.” Months earlier the Elders of Chrislam had identified the Reborn saboteurs and handed them over to ASTROPOL, but they had stubbornly refused to defend themselves. There was also another problem: where could one find an unprejudiced jury? Certainly not on Earth, and probably not even on Mars.
Moreover, what was a suitable sentence for terracide? It was a crime which, self-evidently, could have no precedent….
It might not matter, if Kali once again threatened guilty and innocent alike. The celebrations might have been premature; quite possibly, there had merely been a stay of execution.
38
TERMINAL DIAGNOSIS
THE “KALIQUAKES” WERE BECOMING MORE AND MORE frequent, though they still seemed to be quite harmless. They always occurred around the same time in the asteroid’s brief day, just before its rotation carried Stromboli around to the nightside. Clearly, the area around the mini-volcano had been absorbing heat all through the hours of daylight, and it came to the boil just before nightfall.
However—and this was what worried Sir Colin, though he had discussed the matter only with Captain Singh—the eruptions were starting earlier, lasting longer, and becoming more vigorous. Fortunately, they were still confined to the one area, almost on the other side of the asteroid from Goliath: no outbursts had occurred elsewhere.
The crew regarded Stromboli with affectionate amusement rather than alarm. Sonny—never a man to miss such an opportunity—had started taking bets on the exact time of eruption, with the result that every evening David had to make considerable adjustments of credit balances.
But, under Sir Colin’s guidance, he was also making calculations of a much more serious nature. Goliath was already halfway between Mars and Earth before Singh and Draker decided that it was time to alert SPACEGUARD—and, as yet, no one else.
“As you will see from the attached figures,” their memorandum began, “there is another force, besides our own drive, affecting Kali’s orbit. The vent we have named Stromboli is acting like a rocket motor, ejecting hundreds of tons of material every revolution. Already it has canceled ten percent of the impulse we gave. That would be no great problem—as long as matters do not become any worse.
“But they probably will as Kali gets closer to the sun. Of course, if it exhausts i
ts supply of volatiles, there will be nothing to worry about.
“We do not wish to raise undue alarm while the matter is still in doubt. The behavior of active comets—and Kali is the last vestige of such a comet—is unpredictable. So SPACEGUARD should consider what additional action can be taken—and how to prepare the public for it.
“There may be a lesson here in the history of Comet Swift-Tuttle, discovered by two American astronomers in 1862. It was then lost for more than a century, because, like Kali, its orbit had been changed by jet reaction as it approached the sun.
“It was then rediscovered by a Japanese amateur astronomer in 1992—and when its new path was computed, there was widespread alarm. It appeared that Swift-Tuttle had a high probability of hitting the Earth on August 14, 2126.
“Although this created a sensation at the time, the episode is now virtually forgotten. When the comet rounded the sun in 1992, its solar-powered jets changed its orbit again—to a safe one. It will miss the Earth by a wide margin in 2126, and we’ll be able to admire it as a harmless spectacle in our sky.
“Perhaps this piece of astronomical history—we apologize to those who are quite familiar with it—will give the public some reassurance. But, of course, we can’t rely on such a fortunate turn of events happening in the future.
“Our original plan had been to leave Kali as soon as it had been deflected into a safe orbit, rendezvous with a refueling tanker, and head back to Mars. But now we must assume that we’ll have to burn all our propellant right here on Kali. We won’t have enough to keep thrusting all the way to Earth; let’s hope it’s sufficient.
“Then we’ll sit here—we won’t have much alternative!—until a rescue mission can be arranged, probably after we’ve rounded the sun and are heading back to Earth orbit. Please advise us immediately if you approve, or if you have any alternative suggestions.”
When the spacefax transmission had been confirmed, Captain Singh remarked a little wearily: “Well, that will stir things up. Wonder how they’ll handle it?”
“I’m wondering how we will,” Sir Colin replied gloomily. “I’ve been thinking about some of the alternatives.”
“Such as?”
“The worst-case scenario—we can’t deflect Kali. Are you really going to burn up every drop of fuel and let Goliath crash as well? How many tons of propellant would it take to put us into a safe orbit—even a grazing one?”
The captain smiled mirthlessly.
“If we do it just before all-burn, about ninety.”
“I’m glad you’ve already worked it out Ninety tons won’t make the slightest difference to Kali—or to Earth—but it could save our skins.”
“Agreed: there’s no point in getting killed—and adding ten thousand tons to the Hammerblow. Not that ten thousand tons would be noticed, in two billion.”
“A good point, but I doubt if it will be appreciated on Earth—when we say ‘Sorry about that, folks’ as we skim safely past.”
There was a long and uncomfortable silence before the captain answered.
“All my life there’s one rule I’ve tried to keep. Never waste sleep on problems that are beyond your control. Unless SPACEGUARD comes up with another answer, we know what we can do; if it doesn’t work, that’s not our fault.”
“Very logical—but you’re beginning to sound like David. Logic won’t help us much after we’ve seen what Kali does to Earth.”
“Well, let’s hope all this doomsday talk is a waste of breath. And unless we can make them believe that Earth is going to be saved, a lot of people down there will go crazy.”
“They already have, Bob. Did you see the suicide statistics in the last quarterly report? They’ve fallen off now—but think of the panics—the rioting—that could happen in the next few months. Earth could be wrecked—even if Kali sails harmlessly past.”
The captain nodded—a little too vigorously, as if trying to shake some unpleasant thoughts out of his head.
“Let’s forget Earth for a moment—if we can. Have you looked at the orbit we’ll be following after we go past?”
“Of course; what about it?”
“The perihelion’s right inside Mercury’s. Only point three five astronomical units from the sun. Goliath was designed to operate between Mars and Jupiter. Can the ship handle such a heat load—two hundred times normal?”
“Don’t worry, Bob. I wish all our problems could be solved so easily. Didn’t you know I’d been closer than that? Project Helios—we rode Icarus for a week either side of perihelion—not much more than three A.U. from the sun. Spectacular—but perfectly safe, if you do it at sunspot minimum. It was quite—ah—interesting, to sit in the shade and watch the landscape melting around us. All we needed was a set of multiple reflectors to bounce the sunlight back into space; I’m sure Torin and his robots can make them in a few hours.”
Captain Singh thought this over with relief but little enthusiasm. He had heard of Project Helios and recalled that Sir Colin had been one of the scientists involved.
It would certainly bolster morale on Goliath, when the sun was ten times larger in the sky than it appeared from Earth, to have someone on board who had been there before.
39
REFERENDUM
ACCORDING TO THE BEST ESTIMATES, KALI NOW HAS
(1) 10% PROBABILITY OF IMPACTING EARTH
(2) 10% PROBABILITY OF GRAZING THE ATMOSPHERE, CAUSING SOME LOCAL DAMAGE BY BLAST
(3) 80% PROBABILITY OF MISSING EARTH COMPLETELY (MARGINS FOR ERROR, 5%)
PLANS ARE BEING DRAWN UP TO DETONATE A THOUSAND-MEGATON BOMB ON KALI, THUS SPLITTING IT INTO TWO FRAGMENTS WHICH WILL SEPARATE BECAUSE OF THE ASTEROID’S SPIN. THEN NEITHER—OR ONLY ONE HALF—MAY HIT OUR PLANET. EVEN IN THE LATTER CASE, DAMAGE WOULD BE GREATLY REDUCED.
ON THE OTHER HAND, DISRUPTING KALI MAY RESULT IN THE BOMBARDMENT OF MUCH MORE EXTENSIVE AREAS OF EARTH BY SMALLER BUT STILL HIGHLY DANGEROUS FRAGMENTS (AVERAGE ENERGY ONE MEGATON).
YOU ARE ACCORDINGLY ASKED TO VOTE ON THE FOLLOWING PROPOSITION. PLEASE KEY IN YOUR PERSONAL IDENTITY NUMBER AND FOLLOW INSTRUCTIONS. YOUR ACCOUNT WILL RECEIVE THE APPROPRIATE CITIZEN’S CREDIT WHEN YOU HAVE MADE YOUR SELECTION.
1. THE BOMB SHOULD BE DETONATED ON KALI.
A. YES
B. NO
C. NO OPINION
40
BREAKTHROUGH
DAVID SOUNDED THE GENERAL ALARM IMMEDIATELY AFTER HE detected the first tremors. Two seconds later he cut the drive, which had been operating at 80 percent maximum thrust. He then waited for another five seconds before slamming the airtight doors that divided Goliath into three separate, autonomous units.
No human could have done better, and everyone reached the nearest emergency module before the hull cracked—luckily in only one section of the ship. Captain Singh made a quick roll call while he was getting into his pressure suit, and asked David for a situation report as soon as all the crew had answered.
“Our continuous thrusting must have weakened part of Kali’s surface—it’s given way—here’s the external video of the damage.”
“Colin, can you see this?”
“Yes, Captain,” the scientist answered from his own safety capsule. “That leg seems to have gone in at least a meter. I’m astonished—I checked all the pads, and could have sworn they were on solid rock. Can I go out and have a look?”
“Not yet. David—ship integrity report.”
“All air gone in forward section—when the break-through happened, we hit against Kali just hard enough to spring a leak. No other damage to Goliath—but when the ship moved, part of the scaffolding pierced tank three.”
“How much hydrogen have we lost?”
“All of it. Six hundred and fifty tons.”
“Damn. That includes our getaway reserve. Well, let’s start cleaning up the mess.”
“Captain Singh reporting to SPACEGUARD. We have a problem, but not a serious one—yet.
“It seems that our continuous thrusting has weakened the su
rface of Kali immediately beneath the ship—and part of it has given way. We still don’t understand exactly why, but there was a minor cave-in—about one meter. The only damage to Goliath was a leak in one compartment—easily repaired.
“However, we’ve lost all of our remaining propellant, so we can make no further alteration to Kali’s orbit. Luckily, as you know, we passed into the safety zone several days ago: according to the latest estimates, we will now miss Earth by over a thousand kilometers—assuming, of course, that Stromboli does not push us back onto a collision orbit again. Fortunately, its eruptions seem to be weakening; Sir Colin thinks it’s running out of steam—literally….
“This accident—er, incident—means that we’re stuck on Kali. Again, that should be no problem. We’ll go around the sun together, and wait for our sister ship, Hercules, to catch up with us on our outward leg.
“We’re all in very good spirits, and looking forward to a safe fly-by in just thirty-four days. Captain Robert Singh, saying good-bye from Goliath.”
“You know, Bob,” said Sir Colin, “you’re beginning to sound like an airline pilot in an old Twentieth-Century film. ‘Ladies and gentlemen, those flames from the port engines are perfectly normal. The stewardess will be coming around in a moment to serve coffee, tea, or milk. I’m sorry we don’t have anything stronger on this flight—regulations don’t permit it. Hic…’”
Though Captain Singh did not consider the situation very funny, he had to admit that there were times when a little humor was a great help.
“Thanks, Colin,” he answered. “That cheered me up. But a straight answer, please—what do you think of our chances?”
Now it was Sir Colin’s turn to be serious.
“Your guess is as good as mine. It all depends on Stromboli. I hope it’s fizzling out—but it’s also warming up as we get closer to the sun. Is our safety margin big enough? Or will we be pushed back on a collision course again? Only God knows, and there’s certainly nothing we can do about it.