Interstellar SF Gets Real: Galactic Settlement by Hitchhiking Among Passing Star Systems

In most science fiction to date, the natural distance between stars is fixed and is too large to span with realistic technologies. Instead, interstellar SF invokes faster-than-light travel or exotic notions like generation ships or human hibernation. Academics outside SF label these stories as fantasy and serious thinkers often assert that humans are stuck in our solar system. These views have negative effects on the broader culture outside SF. The problem can be solved by writing SF that includes two facts: (1) stars naturally move and (2) people can live among comets. When stars pass near each other, sometimes their clouds of orbiting comets overlap. During these times, comets from the two star systems pass close enough for real technologies to transport human settlers across the gap. This implies new possibilities for interstellar SF. We suggest options for world-building, opportunities for conflict, and enhanced SF themes. With these options, readers who are neither SF scholars nor astronautical engineers can realistically foresee interstellar settlement by people like themselves. The broader culture benefits from more sense of purpose and more hope.