“If I didn’t know that by now, we might as well give up. It’s the explosion of a star.”
“A very violent explosion. When a star system goes supernova, it can shine a hundred billion times as bright for a month or two.”
“But Vronsky said that according to theory, Alpha Centauri was the wrong type of star. It couldn’t go supernova.”
“Mr. President, can and can’t make sense when you’re talking about the future. We’re talking about the past. It did. Time for a new theory. But here’s what the astronomers tell us happens in a supernova. First, you get a runaway fusion reaction inside the star, and the outer surface blows off into space. That’s what we see. People in New Zealand and Australia noticed it first — it was early evening — and they watched it get brighter and brighter until it was like a second sun. That’s when the climate people started modeling the effects on the weather, and warned us to expect extreme conditions up here in the north as well as down south.”
“You can speed it up, Grace. I’ve heard this much.”
“I’m sorry, sir. I’ll keep it short. When the star’s outer layers blow off, they form a spherical shell. The shell is opaque to short wavelength radiation, so for a few weeks the X rays and gamma rays created in the fusion explosion stay bottled up. You’ve got billions of hydrogen bombs going off in there, but what you see at this point is just the bright outside of the shell.”
“That’s what we had until the middle of March.”
“Yes, sir. But as the shell expanded it became thinner. And it wasn’t of uniform thickness. Finally part of the shell was weak enough for high-energy radiation to get through. There was a huge squirt of X rays and gamma rays, all coming out at the same time. The ’accident of geometry’ that Dr. Vronsky mentioned was that the beam of radiation came in our direction. It hit Earth on March 14.”
“Why didn’t it kill everything in the Southern Hemisphere? X rays and gamma rays are deadly.”
“They are. But our atmosphere is opaque to most of those wavelengths and the radiation that got through hit the open Pacific Ocean and Antarctica. It did no direct damage to heavily populated areas.”
“Keep going. I know this is going to end up bad, but I don’t see how.”
“The radiation absorbed by the upper atmosphere had enough energy to strip electrons from gas atoms. Enormous numbers of them. Electrons are charged particles, so they moved along magnetic field lines and kept building up their energy until finally — all at once — they produced a huge pulse of electromagnetic field. And that’s what wiped out the microchips.”
“All the chips?”
“Every one on the surface of the Earth, or close by in space. The pulse travels as well through vacuum as through air. But there’s an inverse square law effect, so the farther away you are from Earth’s atmosphere, where the pulse originated, the less power the pulse will have. That’s why the manned platforms and the polar metsats are dead, in low Earth orbit, but the geosynchronous metsats and comsats in high orbit are working fine — if only we could receive from them.”
“All the microchips. And it’s hard to find equipment without a microchip somewhere inside it. I assume there’s no way the chips can be repaired?”
“No, sir. They’ll have to be replaced. And it’s going to be a long job, because the production plants that make the microchips depend on their own microcircuits to do it. We face a difficult bootstrapping operation. Until the factories are up and running, we’ll be relying on technology from the last century.”
She paused. Saul Steinmetz had closed his eyes, and sat slowly nodding his head. “Do you have any more questions, Mr. President?”
“Yes. Why me, God? Why did it happen when I was President?” He opened his eyes and smiled at Grace Mackay. “I don’t expect you to answer that. I’ll be seeking answers from a higher authority. Thanks for the explanation.”
“My privilege.” She stood up, turned smartly, and marched toward the door.
“One other thing,” Saul called after her. “You say that distance helps. What do you think the chances are for the Mars expedition?”
She turned in the doorway. “I’ve been afraid you would ask me that. I think they could be alive, and their ship in good working condition.”
“In another few days they’ll be back in Earth orbit. The plans for their visit to the White House were on my calendar before any of this started.”
“Yes, sir. They are scheduled to retrofire and return to an orbit around Earth on March 26. The trouble is, I see no way to bring them down. The members of the Mars expedition are probably still breathing, Mr. President. But they are dead.”
4
Regardless of opinions back on Earth, Celine Tanaka did not feel dead. She felt very much alive.
Stupid was another matter. How could all the Mars crew have missed something so obvious? Logically, they ought to have known about Supernova Alpha before anyone else. After all, space was all around them, their only scenery. They should have noticed anything happening in it.
After the fact, Celine tried to justify their oversight. First, they had been on the way home for seven months, and scenery that never changes — or changes too slowly to notice — loses its charm. Second, although no one on board would mention it, they were all thinking ahead to the return to Earth. Their place in history had been secured by the Mars landing, but at the time the aerobraking problems on the way down and the loss of one unmanned lander had occupied everyone’s attention. The return from the Martian surface had been uneventful but equally tense. Only on the way home, with nothing to do but wait, could you give way to the sense of anticipation and excitement.
So Supernova Alpha had begun its change when everyone aboard the Schiaparelli was off guard. Celine, as head of instrumentation, did notice the apparent malfunction of one of her star trackers. It was reporting a photon variation above threshold. Since the trackers’ target stars were chosen as stable stellar references, the tracker obediently noted the anomaly and turned itself off to prevent damage. But Celine saw no reason to investigate the problem immediately. There were four other working star trackers, and in any case spacecraft attitude control was not important during this phase of the mission. A fix could be made anytime in the next few weeks. She thought she would do it at the end of the work period.
In retrospect, that was less than totally conscientious. But no one else on board — except maybe Zoe — would have acted any differently.
Ten minutes after the star tracker went off-line, Ludwig Holter wandered into the instrumentation center. He had the face of a wicked elf and the slight build to match, and Celine noticed that he moved with a free-fall grace and economy of effort that three years ago would have seemed impossible to all of them.
“Celine, I’m picking up a report from Canberra of anomalous short-period variation in the brightness of Alpha Centauri. Do we have anything looking that way?”
Although he was German, his English was better than her Philippine/Hawaii mixture. Celine glanced at the big board. “Only one of our navigation star trackers, and it’s off-line for checking. None of our scopes is observing in that direction. Want me to switch into the DOS, see if it’s taking a look?”
The Distributed Observation System was a complex of forty-eight telescopes in Earth orbit, all tightly controlled to observe a common target. The Schiaparelli had been designed to receive the DOS output data stream, though the crew rarely did so.
Ludwig scowled from beneath blond bangs. “Nah. I’m sure DOS is booked up weeks ahead, and it takes hours to switch targets. Can you put our big scope on it?”