Authors: Charles Sheffield
Tags: #Science Fiction, #Twenty-First Century, #General, #Adventure, #Fiction
"Alpha Centauri is a double-star system," Wilmer said, in his relaxed drawl. "Double stars can become a Type Ia supernova, but only if one of the two stars is a white dwarf. Alpha Centauri doesn't qualify."
"Then I guess Alpha Centauri doesn't know that," said Zoe. "It's not a good day to be an astronomical theorist. Hey, give me some air, folks." She wriggled around to face Wilmer Oldfield. "What do you mean, just getting going?"
"If this is a supernova, the increase in brightness will be as much as a hundred billion. We are still far short of that."
"Are we going to be safe?"
Celine listened for Wilmer's answer with special interest. In addition to being in charge of instrumentation, she was also the expedition's physician. The medical supplies and equipment were adequate for "normal" emergencies, but a supernova didn't qualify.
"Safe?" Wilmer blinked his eyes and rubbed his stubbly beard as though such a question had never occurred to him. Celine's guess was that it hadn't. He was a super scientist and a sweetheart, but sometimes he seemed on a different wavelength from normal people.
"I dunno," he said after a moment. "But I can work it out easy enough. The bigger star of Alpha Centauri is pretty much a look-alike for our sun, same spectral type but a little bit brighter. It's about one and a third parsecs away, so that's about two hundred seventy thousand times as far as the sun is from Earth. If it becomes a hundred billion times as bright as usual, it will look a hundred billion divided by two hundred seventy thousand squared as bright as the sun. So there you are."
He paused, as though that was the end of the story. "Translation, Jenny," said Zoe. "Do the calculation, would you, for people like me. How bright will it be?"
"One hundred billion divided by two hundred seventy thousand squared is one point thirty-seven." Jenny Kopal was in charge of computers, and the common view was that she had a personal one inside her head. Celine found it easier to ask the dark-haired Hungarian for the answer to calculations rather than keying it in herself.
"That's
bright
," Reza said. He giggled. "Sell Sunscreen 100, you'll make your fortune."
"Well, that could be off a factor of two, one way or the other," Wilmer added. "But Reza's right, Alpha Centauri as seen from Earth will be bright, maybe as bright as the sun. Of course, that's only for a month or two, then it goes dim again."
Except for Wilmer, the group in front of Celine moved in concert, edging away from the chamber window.
"Are we in danger?" Zoe asked. Wilmer shrugged. He had the long limbs and wide shoulders of an outdoorsman. That, combined with his Australian accent, had Celine in the first months of their acquaintance expecting him to talk about wombats and wallabies rather than quantum field theories. "I don't see why," he said at last. "We can handle solar radiation. We have the inner shielded area in Section One, in case of big solar flares." He looked thoughtful. "Course, when the gas shell of the supernova expands, a big slug of gamma rays will break out. We have no idea which direction they'll emerge. But we have enough shielding to handle that, too. The big problem is going to be the high-energy particle flux. That will carry a lot more energy than the visible light or the gamma rays. It'll be an absolute killer."
Zoe came bolt upright. "And you say we're not in danger!"
"We're not. The light and gammas travel at light speed, but the particles are much slower—five to ten percent of light speed. It will take them fifty years to get here."
The group relaxed again.
"Fifty
years
," Zoe said. "I don't care about fifty years. I was worried about fifty minutes or fifty hours."
Wilmer shook his head. "No worries. We will be fine."
"
We
will be fine." Alta McIntosh-Mohammad was the
Schiaparelli
's chief engineer, Scottish-Indian and taciturn. Whenever she spoke, the rest had learned to listen. "But what about
them
? Back on Earth. Will they be all right?"
"Wilmer?" said Zoe.
There was a much longer silence, during which Alpha Centauri visibly increased in brightness second by second. Celine thought of her mother and stepfather, now on a field trip in central Kalimantan. They were very resourceful, they would be fine. Wouldn't they? And her brother Hiroshi should certainly be safe enough, on the west coast of Canada. But Wilmer's lengthy pause was worrying, and the appearance of the rest of the crew suggested that they were having the same thoughts as Celine. She could see uneasiness on every face, tight-lipped control, and a reluctance to look at each other.
"That's a much harder question," Wilmer said at last—not what Celine was hoping to hear. "You put another illumination source, maybe as bright as Sol, down at sixty degrees south. It will have a hell of an effect on temperatures and global weather. In the long run, you'll see some ice melt and sea-level rise. But for good quantitative answers you need the best models on atmospheric circulation patterns. We don't have anything like that on board—though you can bet they're hard at work down on Earth."
"I hope bad weather won't screw up our landing plans," Zoe said. "The last thing we need is high winds and storms. I suppose if we have to, we can sit it out in orbit."
With hindsight, Celine would realize that Zoe had still been seeing Supernova Alpha as a problem for Earth but at most a minor inconvenience to the expedition. And everyone had taken their cue from the leader of the party. So after another half hour of watching they one by one wandered away, leaving the observation chamber for their own quarters.
Wilmer and Celine were the last to go. He was simply fascinated by the supernova and wanted to see as much of it as possible; Celine had her own reasons. She wanted a quiet place to think, and the observation chamber was as good as any.
Competition for the Mars expedition had been incredibly fierce. Each of the winners had multiple capabilities and would have multiple duties, but everyone knew that competence was only part of the picture. Politics was the other variable, beyond a candidate's control. The selection committee somehow had to achieve a mixture of crew members both competent and internationally balanced. Every crew member also had to be both vitally important and totally expendable. If someone died on Mars, there could be no sending home for replacements.
So in Celine's mind, Ludwig Holter satisfied continental European pride, handled all communications, and in a pinch took over the computers. Alta McIntosh-Mohammad pleased Britain and the Federation of Indian States and was chief engineer, while Reza Armani was American-Iranian and served as backup pilot in addition to his role as areologist. Zoe Nash herself knew all the communications systems and represented both Africa and Asia Minor. And Jenny Kopal, Hungarian with a strong dash of Russian, had spent enough time with Celine to be fully familiar with the
Schiaparelli
's major command and control instrumentation.
Celine still wondered how she herself had been lucky enough to survive the final cut. Perhaps it was pressure from the Eastern lobby, with a little Hawaiian help. She knew she was hardworking and pretty bright, but the others of the crew were more than that. They were spectacular.
And in that company, the stand-out oddity was Wilmer. Everyone admitted it; they were highly competent, but he was a
real
genius. No one on board approached him as a pure scientist—and not one of them wanted him anywhere near when they were doing their jobs. He was as clumsy as you could get, and equipment fell apart in his hands. He was also the odd one physically. The rest were below average height and weight, Wilmer was tall and deep-chested and rangy.
Their special capabilities and redundancies had all made sense, even before they headed for Mars. Only when they had been traveling for a few months did Celine conclude that the faceless selection committee back on Earth had employed yet another set of criteria. The crew were matched not only in technical skills, but in personality types. They had been paired, she suspected, before they ever left Earth. The group was not particularly highly sexed, but unless people are actually neutered or drugged into an asexual stupor, couplings are bound to occur. Reza Armani and Jenny Kopal had paired off early, followed a month later by Ludwig Holter and Alta McIntosh-Mohammad. Celine thought them unlikely duos. Reza, for example, had a deep mystical streak and sometimes seemed both illogical and half-crazy. Jenny, in contrast, was a cool and objective atheist. But of course they hadn't consulted Celine before sleeping together. And she could imagine the reactions when she and Wilmer began to share quarters: Whatever does he/she see in her/him?
Zoe Nash had no one, man or woman, and seemed content with that. She was five years older than the rest, who were all within a year of each other, and maybe she saw them as her children. And maybe they liked that. They had lots of respect for each other, but of all possible losses Zoe's would be the hardest for everyone to take.
The personality types were varied in one other way that was hard to define, although Celine had pondered it often enough. Zoe was certainly the authority figure. Reza was the class clown and cut-up king, sometimes far-out enough to make Celine wonder how he had passed the psychological tests. But what were the rest? She could never decide, with one exception: Celine herself was the expedition's worrywart, a Cassandra who could always imagine a dozen ways that things might go wrong. Unlike Cassandra's, though, her own dire predictions had never come to pass.
Yet.
And that, she suspected, was why she remained in the observation chamber with Wilmer, and stared at Alpha Centauri. She was worried, and not sure why. He hardly seemed to know that she was there, until she said, "Wilmer, we talked about what the supernova might do to Earth. Could it do anything to the rest of the solar system?"
"Nothing to worry us. It will melt the ice surfaces on the moons of the outer planets, but as Alpha Centauri dims they'll freeze over again."
"What about the sun? There will be a lot of extra heat, all pouring into one side of it."
"It's a lot by terrestrial standards. In solar terms, it's nothing."
"It couldn't cause big solar flares, or anything like that?"
"I doubt it. Even if it did, Section Two of the
Schiaparelli
is well shielded against that sort of thing. We'll have plenty of notice, we'll just retreat there for as long as necessary. We're safer here on the ship than we would be down on Earth."
Celine could see why Wilmer was so good as a partner for her. No matter what happened, he stayed calm. And he could usually give her a sound, logical reason why her worries were groundless.
This time, though, she had the awful conviction that she would be right, and he would be wrong.
* * *
Supernova Alpha brightened and brightened. The crew of the
Schiaparelli
was in the best possible position to observe it. Four weeks after the first brightening—and one week before the change—the expanding gas shell around the star was big enough to show a visible disk to the on-board telescopes. From the second day, Celine had tuned their communications antennae to receive images from the DOS in Earth orbit. They all watched the fiery sphere pulsate and shiver under the force of explosions deep inside it. Wilmer did inverse calculations to determine the energy release from the observations. The numbers he quoted, in his dry, matter-of-fact way, were enough to make Celine shiver.
"If there were planets orbiting Alpha Centauri . . ." Alta said gloomily, when she, Celine, and Wilmer were together in the main galley of the
Schiaparelli.
She was the expedition's number two pessimist, right after Celine.
"Then you would be quite right to employ the past tense." Wilmer nodded to a display, where Alpha Centauri was now constantly displayed. "If they were ever there, they're cinders."
Celine didn't say anything. But after they had finished eating she went again to Section Two. There she checked that the quarters they would retreat to in case of a big solar storm were fully furnished with supplies. Then she did what she had done every day since the first blossoming of Supernova Alpha; she examined sequences of visible-wavelength images of both Alpha Centauri and of Sol, looking for changes in either.
Of course, she didn't see anything. The huge pulse of gamma rays from Supernova Alpha, when it finally came, was invisible to human eyes.
The instruments, however, had sensitivity to everything from hard X rays to long radio waves. They caught the leap in the ambient gamma-ray level in the first fraction of a second, extrapolated the upward curve, and sent a warning bellow through the whole ship.
The crew had been well trained.
Better to overreact than underreact.
They headed at maximum speed for Section Two. Celine, in a bizarre way, felt vindicated. She had expected trouble, and here it was—and thanks to Celine they were ready, food and water fully stocked, extra instruments installed so they would know exactly what was going on outside.
Not much space, of course. They were in an emergency shelter, not a luxury hotel. But Celine sat bug-rug-snug and not unhappy between Wilmer and Ludwig, watching the gamma-level readout.
It was calibrated so that a level of zero equaled the mean solar gamma flux with a quiet sun. The current level—sixty-three—only meant something if you knew that the readout scale was the base-e log of the gamma intensity. That was easy to deal with if you knew, as Celine did, that e
3
is about equal to twenty. So an increase of three in readout value was equivalent to a factor of twenty multiplier in actual gamma-ray level. Readout level sixty-three then meant that the current gamma flux was 20
63/3
of the usual value. 20
21
was rather more than 10
27
. Space outside the shielded compartment of the
Schiaparelli
was hot, hell-hot, with the gamma-ray burst from Supernova Alpha.
And still Celine, who would conclude in retrospect that she was an idiot, thought they were sitting pretty inside their shield. She hadn't even bothered to include a display showing anything of what was happening back on Earth. It was Ludwig, sitting with his miniature ear-link tuned to open communications channels, who after a few seconds grunted, sat upright, and said, "What the hell is going on?"