Throughout the history of life on Earth, there has really only ever been one constant. Death. During the long period before the Cambrian, entire ecosystems popped into existence only to collapse with the rise of modern taxons at the dawn of the Paleozoic. Between the Permian and the Triassic, a rapid temperature increase brought about by volcanic activity in Siberia meant the end for more than ninety percent of everything that showed up in the fossil record. The great ancestors of the birds were then able to diversify. They spread out across the Earth and lived for over a hundred million years, growing from small creatures that scrambled through the underbrush into behemoths that shook the Earth as they moved. Then, a random hammerblow from a member of the Flora asteroid family cut them down. Within a decade, all that remained were bones turning to fossils in the sediment left by the first thunderstorms after a ten year winter.
Humanity had a good run. We rose from a pretty unexceptional branch of the mammal family tree, closely related to the rodents and a little more closely related to the tree shrews, to complete dominance over all life on Earth. Well, at least all macroscopic life. The enormous brains gifted to us by a few fluke mutations allowed us to shape the world to our whim. Entire environments were wiped out and created. Prairies turned to farmland, savannahs turned to desert, saltwater estuaries turned to concrete canyons, and tropical rainforests turned to ashes and wasted pastureland. Along the way, though, we dug up the bones left in the sandstone hills that had once been thunderstorm runoff. We saw those enormous creatures, along with the older amphibian monsters that had dessicated and then been buried beneath the dunes of the desert in the heart of Pangea.
The rules were clear. Death was a constant.
There wasn't any real surprise in 2667, when JESSICA sounded her warning. By that point, we had learned to divert and even mine smaller asteroids like the one that hit Chicxulub, but we still knew that the nature of the Great Game of Life hadn't changed. A real monster, whipping in from interstellar (or in this case, intergalactic) space, could not be diverted. Echidna was a body from the Oort Cloud of a solar system thrown our way when two enormous spiral galaxies collided long before the formation of the Earth. Its star had died and the orbiting bodies had been scattered by gravitational encounters.
Echidna wasn't that large in the big scheme of things. Half the size of Pluto, maybe. The big scheme of things didn't matter. She was going to hit the Earth at a thousandth of the speed of light. The crust of the Earth wasn't even going to shatter. With heat that high, it would turn to liquid near instantaneously. The predicted zone of impact, the Precambrian craton of South Africa, was going to splatter, a wave of liquid rock that would partially solidify as it came back down, creating second impacts ahead of a storm of something that could only be called fire by rough analogy.
There was no way that the off world colonies could support fifteen billion new people. The Moon was evacuated due to the high likelihood of secondary impacts, then JESSICA shut down the ports on Mars to all incoming traffic. Autonomous supply vessels still left the Vastitas Borealis for the few manned asteroid mines and the research stations on Europa (along with the single lonely Japanese outpost near the South Pole of Enceladus). Anyone coming in, though, would be shot out of the reddish grey sky by a railgun under the direct control of the WC. She entrusted no one else with the responsibility.
The message was clear. Mars wasn't suitable for mankind yet. Life there was underground, whether in the human-made caverns under the enormous boreal plain or in the natural, water-filled caverns blocked to all exploration by international treaty due to their native microbial colonies. In time, it would become a home. For now, though, the resources just weren't there. The asteroids would never sustain us. Any ship small enough to evade JESSICA's watchful eyes would have no hope of even reaching the icey moons, where massive, dark oceans hid the kilometers-long, glowing bodies of their eternal sovereigns. Our only real home in the solar system, for now, was Earth. It would soon belong to JESSICA alone. She would not be deactivated like the other World Controllers when her tome came to be replaced, it had been decided. Like the others, she would be stored in a data center buried in the rocky crust of 4-Vesta, but unlike the others she would sent back to rebuild as soon as the Earth cooled enough for that to be possible. She could have an entire world and its material wealth to expand into. She would be a god. For her part, JESSICA really had nothing to say on the issue. I was one of the custodians present when the Governing Assembly called her up to give her the news. They actually had us haul one of her larger projectors into the Chamber in Tokyo, so that she could stand there in the center of the giant hall in a form conjured up from the air. Nominally it was to check her response. Maybe they just felt more comfortable telling this to something that looked like a human being.
None of them knew that the seven year-old in a green and yellow floral sundress, with curly black hair down to her waist and a straw gardening hat, was a real person. Most of the others were amalgamations of fictional and historical children. This one was the daughter of the engineer who built the cooling systems, Dr. Patric Isidoku. Her real name was Akhona, I think. JESSICA had been picked out two hundred years before for the 2630 Series WC. They managed to salvage enough of her brain to culture all of the cell lines for the computer's biological components. JESSICA wasn't Akhona, really, but I do wonder if she was somehow more human than her predecessors. Sounds ridiculous, I know, but her expression and her silence that day stuck with me.
For those human beings left waiting for the impact, though, there were a few decisions left to be made. Did we wait to die? Choose euthanasia? A few really did attempt to make it to Mars. That was euthanasia by a different route. A lot fewer turned to religious extremism or to hedonism than you might expect, at least in the first three years.
I opted for a longshot. A fleet of four "arks" were approved for four solar systems with known habitable planets. They were packed with all settlers would need to establish self-sufficient colonies like those on Mars. Still, a long shot. No human interstellar missions had ever been attempt because of all that could go wrong over the course of, for the shortest trip, just under four centuries.
I booked a trip on the Hope. The ship with the shortest voyage, Prayer, had already filled. When the Hope left its dockyard in Low-Earth Orbit, we all filed into the cryo storage rooms. None of us really expected to wake up again. Most of us didn't.
Not that it mattered.
See, here's the thing. Echidna was still three years out. JESSICA used that time to study alternative options, mostly in secret, and she finally found one. Travel through hyperspace had been discussed before, but it seemed impossible to fit anything larger than a hydrogen atom into that compact place. She figured it out, though, and with a year to spare and a dozen planets within easy reach, Grey Ridge, the planet we were headed to, wasn't even part of the first wave of settlement. The mountains in that Ridge were too high and too broad, I guess. Not as much room for agriculture as some of the others.
I'm not unhappy, looking down from the enormous window of the Hope across the night side of a world illuminated with centers and corridors of light. I know that I made the most rational decision that I could have, all things considered.
The other ships were intcepted, because their paths crossed the great hyperspace routes. Their cargo was destroyed en route, because it wasn't really just a cargo of humans, food, and animals.
JESSICA, as the core of the Galactic Controller, told us that she had been unable to find our beacon and assumed us lost. Then, she apologized for not destroying us in our blissful unconsciousness.
In just over half a millennium, mankind crossed that last barrier to dominance of all life. Humanity wiped out all pathogens. Both human diseases and agricultural pests. All those not inadvertently put in cold storage and shot out into the stars, at any rate.
We have two minutes left before one of the few nuclear weapons still in existence detonates in the core of the Hope. Two thousand megatons will make one hell of a light show for the people on the coasts of the giant southern continent.
I don't blame them at all, but I do hope that they still understand the rules of the Game. You can't kill death with fusing deuterium. It finds everyone eventually.