Prologue, Part 1
BOOM. Crackle. Hiss.
Four hours, twenty-six minutes and 9 seconds later (as adjusted for relative Earth time)...
BOOM. Crackle. Hiss.
Cycle continues. This is the signal that heralded the end of Earth.
Prologue, Part 2
In April of 2026, the joint American-Chinese Deep Space Gamma Surveyor satellite happened to detect a peculiar signal less than a light-year from Earth. It was rhythmic, predictable and matched no known natural source of emissions. The blue-shifting of the radiation, coupled with the triangulation of the signal by the orbiting of the Earth, revealed that whatever was creating the signal was moving directly towards Earth at 5% of the speed of light (or 53,960,000 km/h). Over the next 10 years, as humanity turned more and more of its listening devices toward the signal, new details presented themselves. The source of the signal was a steadily reoccurring thermonuclear explosion. This series of explosions seemed to be decelerating towards the Earth. Estimated arrival time, at current deceleration: 88 years, 3 months and 2 days from time of the initial detection of the signal. Whatever this phenomenon was, it would reach the Earth-Moon system in July of 2114.
With several of the world's most powerful telescopes and detectors tracking the object and its leading scientists working to learn all they could, the phenomenon remained a mystery until 2074. In that year, in between the rhythmic thermonuclear explosions, faint radio signals were heard coming from the object. In addition, both ground- and space-based deep space imaging telescopes started to get vague impressions of the object's configuration and shape. It seemed to be about 13 miles long and a mile and half wide. Massive, 20 mile-across concave dishes appeared to be attached to each end of the object.
Prologue, Part 3
Even with grainy, and some would say 'overly', enhanced images, most scientists could not help but compare the object's configuration and properties to the long-theorized Orion project, first conceived over a hundred years previously by Freeman Dyson. The Orion project was a primitive interstellar concept that involved using steady thermonuclear explosions to propel a well-shielded spacecraft to a low percentage of the speed of light.
Others claimed that it was clearly a weapon, sent to destroy the Earth, as a mass of that size, moving at that relativistic speed, would physically destroy the planet. Perhaps, it was an unusual, but natural, object, such as a strangelet, a Quark star or a brown dwarf. The debate began loud and strident, but quickly faded as new telemetry came in.
The data matched the initial hypothesis. This must be an interstellar craft, created and operated by intelligent extraterrestrial life. And it was hurtling towards Earth. Assuming the craft took a linear path through space, its start point was a star system nearly 20 light years away and had been traveling for at least 400 years. Once this was determined, archives were scoured to find any data on the origin system. According to various Medieval European artworks and Chinese records, in the 1600's a bright new star appeared in the sky, at the calculated start point of the craft. Now, there is merely a small, dim and strangely distorted nebula in its place.
It was concluded that these interstellar travelers were not conquerors. They were refuges. Perhaps the last, great hope of their species, flung into the silent void towards the only place that may provide a glimmer of hope. Their desperate destination was an unassuming system that happened to have a few rocky planets in the Habitable Zone: our Solar System.
Given the nature of their craft, the travelers were not much more technologically advanced than we. Perhaps, even less so, considering their use of simple fusion explosions as propulsion. Where were their ion drives, their Anti-Matter impulse engines, their fantastical Warp Engines? Nothing was known about these alien people, besides their bravery and commitment.
We were not alone. And soon, far too soon for our world's cultures to absorb, we would be hosts to an unknown alien generation ship. As the craft grew closer and continued to decelerate, we began to get clearer and clearer radio chatter in between the nuclear explosions. Scientists and laymen alike recorded and attempted to translate the data streams. It was the greatest cryptological puzzle of all time. The prize would be to be first to understand intelligent life beyond Earth.
At first, there were hundreds of frequencies burbling from the device, thousands of sounds, voices perhaps, and technological signals. Over time, the number decreased. Some frequencies went entirely silent. In 2099, the last organic-sounding transmission ceased. It was soft, barely audible over the distance and distortion. Then, only transponders and automated signals beeped on. Over the next few years, most of those slowly and quietly died out, as well.
Prologue, Part 4
The beings that had sent this object on its unprecedented journey had done so with pristine precision. It was calculated to have produce one last decelerating nuclear blast while in the vicinity of the asteroid belt, located between Mars and Jupiter. From there, with conventional retro-rockets, it would slow a bit more and gently enter the Earth's orbit at about quarter of the distance to the Moon. Presumably, from that safe orbit, landing craft would eventually detach and fall to Earth, safely transporting its estimated 200,000 passengers to their new home.
As the vessel entered local space, the entire world watched with rapt attention, the very soul of humanity reaching out to the lonely wanderer of the stars. Orbital spacecraft of all kinds, national, military and private, approached the massive construct. Far more massive than any single object created by humanity, it was slightly longer than Manhattan island and about half as wide. It was cylindrical, its main body still rotating at a speed as to create 0.9 Gs on its inner surface: a practical form of artificial gravity. It's fore-facing dish was scorched, pitted and nearly fractured through by the rigors of its journey and deceleration. The primary hull was similarly pock-marked and scored, but seemingly intact.
Eventually, after thousands of scans, readings and welcoming signals that returned no reply, humans connected to the hull at an egress point. The airlock was mechanically practical and used a technology easily understood by the men and women accessing it. It opened dutifully and, protected by the most advanced technology available, we stepped inside.