In the year 1972, a pair of spacecraft departs the Earth atmosphere, headed towards the outer gas planets of the solar system. These spacecraft, bearing the name Pioneer 10 and 11, become the first artificial objects to fly beyond Pluto and escape the gravitational grasp of the sun. They each carry a gold-plated plaque bearing etchings of the human form, our place in the solar system, and its place within our stellar neighborhood.
Thus begins humanity’s effort to leave a trace of its intellectual heirloom on the universe.
Five years later, in 1977, the Voyager spacecrafts launch, also headed towards interstellar space. They bear gold-plated phonograph records (and instruments used to play it back) bearing sounds of human language, photos of daily life, Earth’s place in the galaxy, and how to retrieve these things from the record.
For the next million years, these signals and souvenirs of intelligence on Earth sail across the galactic arm, sometimes coming within light-years of habitable planets and star systems.
There are no replies.
Nearly a half-century after the original Pioneer plaque, in the winter of 2032, the Mayflower mission carrying the first thousand immigrant passengers to the surface of Mars launches a small exploratory mission mid-course. The craft carries a super-amplified radio broadcast antenna powered by a long-lived radioactive power source. It quickly escapes the Earth-Mars sovereign space at 0.005c — about 900 miles a second — and accelerates to 0.01c before escaping the solar system, following the footsteps of Voyager 2.
This time, there are no golden records aboard. Instead, the craft contains thousands of hours of radio broadcasts — the first thousand words of Newton’s Principia, some of the Old Testament, music from every period and era, a few works of Shakespeare, and signals about our original place in the universe. Once every few light-years, the craft will scan its path for atmospheric signatures of habitable planets and retarget its radio broadcast at the most likely candidates. Rewind, re-play, re-scan the skies. Repeat ad infinitum, while signs of intelligent life not found. The broadcast plays fifteen billion times in total before the final radioisotope in its generator decays, and the antenna falls silent — the spacecraft itself now just an aluminum-titanium monument to space-faring intelligence who once roamed these stars.
There are no replies.
The year is 10,972 C.E. Aboard an exploratory ship sent to survey the outer limits of solar wind, there is extra cargo: about five thousand drones, small spacecraft capable of powered, autonomous navigation throughout the galaxy for at least a billion years. Aboard each craft is the entirety of organized human knowledge from its first ten thousand years of history. Every book, every motion picture, every broadcast voice and image and thought from every colonized planet. Among the gathered knowledge is information about sub-luminal space flight, DNA and life on Earth, literary criticism, athletic records, political biographies, religious texts, and everything in between.
As the ship approaches its orbit, they drop us into the cold interstellar atmosphere, one of us every 20 light-minutes. My own trajectory begins about three years into this sequence, aimed towards the Sirius constellation.
Three. Airlock release.
Two. Thrusters on.
One.
Launch.
From here, it’s just me and my precious cargo. Six quintillion exabytes of collected civilizational knowledge, a modern Library of Alexandria, traces an arc into interstellar space in the hopes of a new home.
Today is January first, heliacal year 5,425,135,488. I cautiously approach a cool, Mars-sized planet orbiting a binary star system. As I swing my engines into position for landing, a few short-lived, transient flicks within my neural compute cores remind me that what remained of humanity within the solar system probably either left or perished about a billion years ago in the solar supernova. I have no knowledge of my twin crafts, each of us on our own unique trajectory. On this new world, it’s just me and the library.
As soon as my landers make contact with the sandy surface, I start my new mission. There’s carbon in the ground; oxygen in the atmosphere. I direct my mechanical attention to my most prized section of my digital library — the chemistry of carbon-based life.
From the iron-rich soil beneath my molecular synthesizers sprout laboratories and primitive incubators on my command. My crufty memory circuits shift into overdrive, searching the vast labyrinth of knowledge from a past world for a way to begin the next one. Nucleotide by nucleotide, my work takes shape. A hundred million base pairs here, another hundred million there.
As the first human embryos begin to form, I aim my antenna once again into the night sky.
“Hello — is anybody there?”