The First Leap
In Asimov's chronology, Alpha Centauri was one of the first star systems reached by humans using early hyperspace technology. Located just over four light-years from Earth, it was the obvious first destination for interstellar colonists.
The colonization of Alpha Centauri and other nearby systems established the pattern that would define the Spacer worlds: small, carefully selected populations using advanced robotics to build comfortable civilizations on new worlds.
Place in the Galaxy
By the time of the Foundation series, Alpha Centauri was one of 25 million inhabited worlds — a tiny speck in a galaxy-spanning civilization. Yet its historical significance remained: it was where humanity first proved that the stars could be reached.
In 'Foundation and Earth,' the search for Earth's location involved tracing the oldest colonization routes backward — from the ancient Spacer worlds through Alpha Centauri and back to humanity's forgotten birthplace.