“Muons,” Antonio interjected.
“Muons,” Hawthorne acknowledged. “Billions per square centimeter. Many times the lethal dose, down to two kilometers deep in the oceans, down to a kilometer deep in solid rock. Everyone on that side of the world soon dies.”
Two kilometers deep? Only one world had such oceans. Horror and relief—and shame at her relief—washed over Dana. “You’re saying the GRB will strike Earth. Not Mars.”
“Both,” Jumoke said hopelessly. “More. It’ll blanket the solar system.”
Blake broke a lengthening silence. “You said a minute or two. That leaves half of each world untouched. What about people, animals, all life on that hemisphere?”
“Ordo…vician,” Antonio intoned, his face expressionless. “They’re dead. Everyone is dead. Everything is dead, only…more slowly.”
Dana couldn’t not ask. “How?”
Hawthorne finger-swiped his datasheet several times, skimming. “From the ozone layer half-blasted away. The solar UV pouring through has become withering, lethal. Much of the oxygen from dissociated ozone recombines with atmospheric nitrogen. I’m hazy on the chemistry, but it means extreme acid rain, with widespread slaughter at the bottom of the food chain.”
“And also a haze of…reddish-brown nitrogen…dioxide reflecting the sunlight. It starts an…ice age.”
Blake shivered. “What’s this Ordovician thing?”
“The Ordovician Extinction.” Antonio straightened in his seat, stroking his scar faster than ever. His voice strengthened, taking on the tone of a lecture. “Four hundred fifty…million years ago. Before anything lived…on land. The second largest extinction ever…of marine life. Animals not native to the…ocean depths soon…died off.” His voice faded and cracked. “Paleo…climatologists…have reasons to believe…a gamma-ray burst did that.”
“When?” Blake asked. “When will it happen?”
“It has happened,” Antonio said. “More than seven thousand…years ago. In three…years at most…the blast…hits us.”
At Dana’s side, Blake trembled. He said, “Respectfully, Governor, people should be told. They deserve the opportunity to make peace with what’s coming, to spend time with their loved ones. Why fritter away their last days in meaningless toil? Why bring babies into the world only to die before they’ve had the opportunity to live?”
“Meaningless toil?” the governor said. “That attitude, Mr. Westford, is why you will keep quiet. Why everyone in the know must keep quiet. The universe has declared war on humanity, and war demands secrecy and sacrifice.
“Without a functioning economy, we have no options. Let the people suspect that the end is near, that we’re all about to die, and society will implode, whether from neglect, looting, or panic. On this world, and the Moon, and countless asteroids, everyone will die for the lack of oh-two or food or water long before the GRB strikes.”
Was ignorance bliss? Or was withholding the truth immoral? Dana didn’t know, couldn’t guess, could not begin to confront the questions. She couldn’t get past the death of everything and everyone she knew, written in the stars.
It was too much, too fast. Her thoughts skittered. Her head spun.
But what was that about options?
Dana asked, “Where are you sending us, Governor? What is our mission?”
4
The only conceivable “mission” was spending time with loved ones before the end. And digging very deep holes, for all the good that would do. Mission? Blake saw nowhere to go. Dana was in denial, hoping that duty could fill her remaining time.
They’d see about that. Dana was family, too, damn it.
In a fog, Blake heard Governor Dennison answer. Her words took a moment to register.
“Scouting the way to a new home.”
Some deep recess of his mind latched onto the governor’s words. Now you’re in denial, Blake told himself, even as the dispassionate, problem-solving facet of him stirred.
Dennison continued, “To survive, humanity must send out starships. Colony ships. Clermont will lead the way.”
Because with its DED, Clermont wasn’t limited in its range by the fuel it could carry. It could, in theory, accelerate till it reached relativistic speeds, could get clear of the solar system before the GRB struck. Clermont could reach the stars.
No matter that their test program had them still two flights away from first attempting a trip to Jupiter, humanity’s farthest outpost. Their longest flight to date had gone a few millionths of the distance to the nearest star—with the DED breaking down once both coming and going.
And no matter that “dark energy” was less an explanation than a label for astrophysical ignorance. Something made the universe expand faster and faster, and Jumoke had found a way to move a vehicle with that something. No one could say what dark energy was. Not in any nuts and bolts, or gluons and quarks, terms a lowly ship’s engineer could understand.
Suppose they made the DED reliable. At relativistic speeds, the ineffably thin gas and dust between the stars would become a hailstorm of radiation—lethal, if still nowhere near as intense as a GRB. And if they overcame the radiation problem? They could never carry enough supplies for a years-long flight. And no one had a clue what they might encounter between the stars. And no one had ever tried to navigate across such vast distances.
The practical problems seemed limitless, but Blake couldn’t help but consider each as it occurred to him. Maybe he didn’t dare let his thoughts run any other way.
“How many?” he asked.
“People?” Dennison said. “A few thousand, just don’t ask me how. Without at least that much genetic diversity, any colony will eventually fail anyway.”
“Which star?” Dana asked calmly.
“One second, Dana,” Blake said. He could not move past one fundamental problem. “Do I remember this correctly, Antonio? The beam from a GRB is many light-years across. In three years, how can any ship get us to safety?”
Antonio gave one of his awkward, forced smiles, the kind that never got as far as his eyes. “No, you’re right. But I think…this one will just…graze us. The gravitational waves are polarized, and that…suggests the…direction of the beam.
“Which star?” Dana asked again.
“We don’t know that yet, either,” Hawthorne
